CFD Exhaust jet wake and thrust characteristics of several nozzles designed for vtol downwash supresion nasa report.pdf

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C O N T R A C T O R

R E P O R T

JET

WAKE AND

VERAL NOZZLES DESIGNED

VTOL DOW NWASH SUPPRESSION

I N A N D

OUT

OF GROUND EFFECT

7 0 F AND

1200

F

NOZZLE

C.C. Higgins

D, P .

Kelly and T, W. Wainwright

E R O N A U T I C S N D P A C E D M I N I S T R A T I O N - W A S H I N G T O N ,D .C . -

JAN U%l? 'Y 1 9 6 6



TECH

LIBRARY

KAFB. N Y

EXHAUST J E T WAKE AND THRUST CHARACTERISTICS OF SEVERAL

NOZZLES DESIGNED

FOR

VTOL DOWNWASH SUPPRESSION

TESTS

IN

AND OUT

OF

GROUND E FF E C T WITH

70' F

AND

1200' F

NOZZLE DISCHARGE TEMPERATURES

By C.C.Higgins, D. P. Kelly,andT. W. Wainwright

Distribution

of

t h i s repor t is provided in the interest

of

informationexchange.Responsibil i ty or hecontents

re s ides in the author or organizat ion that prepared

it.

Prepared under Contract

No .

NASw-908

by

THE BOEING COMPANY

Renton,Wash.

for

NA TIONA L A ERONAUTICS AND SPACE ADMINISTRATION

F o r s a l e b y t h e C i e o r i n g h o u s e o r F e d e r al S c i e n t i f i c an d Te c h n i c a l n f o r m a t i o n

S p r i n g f i e l d , V i r g i n i a 22151

-

P r i c e $3.00



. . -

- . . .

.



EXHAUST J E T WAKE AND THRUST CHARACTERISTICS OF SEVERAL

NOZZLES DESIGNED FOR VTOL DOWNWASH SUPPRESSION- TESTS

IN

AND OUT OF GROUND EF FECT WITH 7 0 ° F AND 1200°F NOZZLE

DISCHARGE TEMPERATURES

By

C.C.

Higgins, D.

P.

Kelly,and T. W. Wainwright

SUMMARY

The jet wake degradatio n and thrust character istics of eleven exhaust

nozzle models designed for dynamic pressure and temperature reduction in the

jet were evaluated statically, using both hot gases and unheated air, and similar

tests were conducted with

a

reference circular nozzle. Addition al tests of

selected nozzles were co nducted to determ ine effec ts of fuselage and/or proximity

of a ground plane upon thrust and jet wake character is tics .

Results show significant jet wake degradation for all suppressor nozzles

tested, both in and out of ground effect and with various fuselage configurations.

Most rapid

jet

wake degradation was achieved with nozzle designs having widely

spaced and/or high aspect ratio nozzle elements. Except for regions very

close to the nozzle exit , increasing exit wall divergence angles provided only a

small improvement in jet wake degradation characteristics.

Thrus t losses were a function of no zzle geo metry, w ith losses m inimized

for nozzle s having sm all exit wall dive rgence an gles and m oderate va lues of

aspe ct ra tio of the discharge openings. The effect upon thr us t of varying spacing

between nozzle elements was not clearly established by these tests. Combining

the nozzles with a fuselage resulted in additional thrust losses ; these losses

further increase d when operating in proximity with a ground surface. Ventila-

tion of the fuselage reduc ed thrust losses, partic ularly with suppre ssor nozzles ,

but all nozzle and fuselage configurations exhibited large los ses when tested in

proximity to a ground surface. These thrust losses were associated with the

large projected fuselage area used in the present tests, and it

is

concluded

that the projected area must be minimized i f excess ive losses are to be avoided

during operation in ground effect.



I

I

. .

_.

. . ..

INTRODUCTION

Ground impingement of the downwash from VTO L aircraft can produce

ope rati ona l problem s of varying degree , depending upon the type of landing

site

and the disc-loading of the

lift

system. With

jet

powered VTOL

aircraft

built

to date, operations have been conducted primarily from prepared sites, thereby

avoiding problems of surface deterior ation from imping ement of high velocity,

high temperature exhaust gases on unp rotected natural surfaces. Some success

has been achieved with operational techniques which reduce exposure time of'the

surfaces to jet impingement, and ways of rapidly preparing the sites with surface

coatings

are

being investigated. Other solutions to the jet impingement problem

have been proposed, but no solution appears to be completely satisfactor y at

this time . Many of the proposed solution s involve some operat ional o r logistic

penalties, and other approaches to the problem must be investigated if VTOL

aircraft are to achiev e maxim um utilization . In practice, a combination of the

best elements of a number of so lutions may be required to achieve the desired

operational capability.

In an effort to reduce the severity of the fundamental problem, particularly

with jet-lift

aircraft

with high disc loadings,

a

program to evaluate various ex-

haust nozzle design factors which could lead to a reduction

of

dynamic pressures

and temperatures

at

the ground surface was undertaken (reference

1).

The

current ef for t represents a follow-on to the program reported in re fer ence

1;

emphasis in the current tests was directed toward an evaluation of the nozzle

performance and

jet

wake degradation characteristics of suppressor nozzle de-

signs under representat ive jet engine nozzle discharge temperatures and

pres-

sure s. Effe cts of

a

simulate d fuselage upon instal led nozzle perform ance,

together with the effects of an adjace nt groun d plane, were evalua ted. Significant

thrust lo sses d ue to advers e press ure field s indu ced on the undersurface of the

fuselage

(i .

e.

,

suck-down losses) have been reporte d by other investigato rs,

references 2 , 3 , and

4 ,

and it was anticipa ted that the higher rates of mixing

associated with suppressor nozzles would result in proportio nately larger

t h r u s t

losses .

Twelve nozzle configurations were evaluated in the current tests, designated

as

Phase I1 tests to distinguish the present efforts from those reported in

reference

1 ,

which

are

designated

as

Phase I

tests.

Of the twelve nozzle con-

figuratio ns tested, three nozzle s duplica ted Nozzles No. 1 , No. 8, and No. 12

of

the Phase

I tests.

Nine additional nozzles, each with four parallel rectangular

discha rge ports, were design ed to investig ate in greater detail the range of

nozzle design param eters applica ble to VTOL

jet

lift

aircraft.

The principal

design parameters were:

1) spacingbetweennozzleelements

2) internalexitwalldivergenceangle

3) asp ect ratio of the elemen ts forming the nozzle exit

2



All nozzle designs were evaluated without fuselage o r ground plane at

both

70°F

and

1 2 0 0 ° F

nozzle discharge temperatures. Surveys of the pres sure s

and tempera tures in the jet wake of each nozzle were made at a nozzle pressure

ra ti o of 2 . 0 , while thrust measurements were made over

a

range of nozzle

pressure r a t ios f rom 1. 3 to 2 .5 . Following these tests, the thrust and jet wake

degrada tion chara cteristics of the circular n ozzle and

two

suppressor nozzles

were evaluated with

a

large simulated fuselage outof ground

effect

in which

vary ing d egre es of fuselage ventilation were provided. Testing was completed

with these three nozzles and various fuselage configurat ions while operat ingt

a distance of five equivalent nozzle diameters from

a

ground plane. Thrust

measure ments and survey s of jet wake pressures and temperatures in the

efflux

ove r the surf ace of the ground plane were obtained in these

tests.

Except for

differen ces of proced ure and eq uipmen t necessita ted by the tes ts at 1200 F ex-

haust gas t emperatures , the cur rent tests were conducted in

a

manner s imi lar

to those of the Pha se

I

tests.

This rese arch was spo nso red by the National Aeronautics and Space

Administration through the Office of G rants and Re search Co ntracts und er

Contract NASw-9d8.

SYMBOLS

CF

cP

L

W

exit area of the nozzle, square inche s

projected

area

of the fuselage on the ground plane, square

inches

aspect

ratio, D /Area o r length/width

m as s flow coefficien t, actual mass flow/ide al mass flow

stat ic pressure coeff icient ,

's

measured

-

PJPt

-Po

n

effective velocity coefficient, effective exit velocity/ideal

exit velocity. Effective velocity

=

(thrust/mass flow)actual

incremental change of effective velocity coefficient

dia me ter of nozzle exit, inches

di am ete r of

a

circular nozzle with

exit

area

equal to that

of

a

non-circular nozzle, inches

length of an element of rectangular exit planform, inches

width of an element of rectang ular exit planform, inches

3



R

radialis tanceromen ter of groundlane,nches

S distanceetweenente rlines of nozzlelements,nches

X f

Y f z axes of a righthandcoordinatesystemwith he Z axis n

the dire ction of flow. Also designat es distance s along

each re spe ctiv e axis from c ente r of nozzle exit, inches

distance from core

o r

apparent core to any point in the

mixing region, measured parallel to the

X

axis, inches

(ref. f igure 29).

x 25, distanceromore o r apparentore oeferenceontour

m a x

at twenty-five

pe r

cent ynamic ressure,nches

(ref.

f igure 29).

x SOT, distancerom ore r apparent ore oeference ontour

m a x

at fifty

pe r

centdifferentialemperatures,nches (ref. figure

2 9,

by analogy).

Y

distance from core or apparen t core to any point in the

mixing region, measured parallel to the Y axis, inches

(ref. figure 29).

y 254, distancerom ore

o r

apparent ore oeference ontour

m a x at

twenty-five

per

cent ynamic ressure,nches (ref.

f igure 29).

Y.50T, distanceromore o r apparentore oeferenceontour

m a x at

fiftyper entdifferential emperatures,nches

(ref.

figure

29,

by

analogy).

h

n

P o

p s f

p s g

height above the ground plane, inches

distance from ground plane to the end of the jet core, inches

load induced on plate , lb .

number of exit segmen ts

a tmospher ic pressure , Ibs / sq f t

stati c pres sure m easu red by orifices in the fuselage surface,

lbs/sq f t

stati c p ress ure mea sure d by orifices in the ground plane,

lbs/sq f t

4



P t

9

m a x

' g m a x

qgS

rnax

static pressure at any specified point in the

jet

wake,

lbs/sq f t

total or stagnation pressure, lbs/sq

f t

total

o r

stagnation pressure

at

the nozzle exit , lbs/sq

f t

total o r stagnat ion pressure at any specified point in the

jet

wake, lbs/sq f t

F

total o r s tagnat ion pressure

at

any specified point on, or

over the ground plane, lbs/sq f t

compressible dynamic pressure at the nozzle exit, p

-

po,

lbs/sq f t tn

compressible dynamic pressure

at

any specified point in the

jet

wake,p - pot bs/sq t

t Z

maximum compressible dynamic pressure measured at any

specified transverse plane perpendicular to the Z axis,

Pt

- po, lbs/sq f t

%ax

compressible dynamic pressure

at

any specified point on, o r

adjacent o, he ground plane, pt -

po,

Ibs/sq f t

.gr

maximum compressible dynamic pressure measured on,

o r

adjacent to, the ground plane at specified distances of the

ground laneromhe ozzle, p

-

po, lbs/sq f t

tgr

max

local dynamic pressure measured on, o r adjacent to the

ground plane p

maximum local dynamic pressure measured on, or adjacent

toheroundlane

,

lb/sq

f t

T

5

jet thrust , lbs



+ t

g l m a x

g'rnax

t t

t t

n

Z

t t

Z

ma x

Z

C

r

Tg rnax

tZ

rnax

e

6

ambient emperature,

F

total

or

stagnat ion temperature , F

total temperature measured in the boundary layer

immediately adjacent to the ground plane, O F

maximum total temperature measured in the boundary

layer immediately adjacent to the ground plane,

O F

total temperature measured in the

jet efflux

over the

ground plane, O F

maximum total temperature measured in the

jet

efflux over

the ground plane,

O F

total temperature at nozzle exit ,

O F

total temperature measured

at


jet wake, O F

maximum total temperature measured

at

any t ransverse

plane perpendicular to the Z axis , O F

length of unmixed jet core, measured from nozzle exi t ,

inches

nozzle wall divergence angle, referred to the longitudinal

axis of th e nozzle, degrees

nozzle wall convergence angle, referred to the longitudinal

axis of. the nozzle, degrees

differential temperature at any specified point on,

o r

adjacent o, he'groundplane

it - - t

o r

tt - to, F

gl

0

g r

maximum differential temperature at any specified point on, o r

adjacent o, hegroundplane

t

-

t o r tt - to,

O F

g1maxrmax

t

0

differential temperature

at

the nozzle exit ,

tt -

to,

F

n

differential temperature

at


jet

wake,

tt

-

to,

F

Z

maximum differential temperature measured

at

any specified

transverseplaneperpendicular o he Z axis ,

tt - to, F

angle subtended by a nozzle sector , degrees

Z

max



A P P A R A T U S A N D P R O C E D U R E

Models

The nozzle models used in this program are described in figures 1

through

4

while figure

5

give s deta ils of the fuselage configurations used with

nozzles 1 . 1 , 2.1,

2. 5 ,

2.6, and 2.8. The circular and twelve segment nozzles

shown in figure

1

were the same nozzles (designated

as

nozzles Nos.

1

and

1 2

during the Phase

I

tests, reference 1)previously tested, while the delta nozzle

shown in figure 1 was a new nozzle of sta inless steel whic h duplicate d the

conto urs of the previous fiberglas s delta nozzle.

The circular nozzle provided

a

reference standard to which the perform-

anc e of the remaining nozzles could be compared, while the delta and twelve

segment nozzles provided correlation with previou's Phase I tests

at

lower

pressure s and tempera tures. Basic characte r is t ics of these nozzles

are

shown

in

Nozzle No. Configuration

1. 1

1 . 2

1. 3

Circular Nozzle

DeltaNozzle

A3

= 5

,

0

=

5

Twelve Segment Suppressor Nozzle,

8

=

6

The additional nine nozzles

shown

in figure

2

consiste d of four rectangular

discharge elements w hich were designed to cover the probable range of nozzle

geometry applicable to

jet-lift VTOL

aircraf t . Nozzle design parameters for

the four-element suppressor nozzles were (1) nozzle internal wall divergence

angle,

0

; (2) spacing

to

width ratio

of

the nozzle elements,

S/W;

and

(3 )

aspect

ratio of thenozzleelement, . Thedimensions of the our-ele mentsuppressor

nozzles

2 . 1

through 2.9,

are

shown in figure 3. Configurations were selected

so that a systema tic v ariation of each of the n ozzle design parame ters w as

obtained for

at least

three nozzles. The nozzles selected

are

shown in the

following table:

7



Nozzle Bo. Variablenvestigatedariableseldonstant

2 . 1

2 . 2

2 . 5

2 . 7

2 . 3

2 . 4

2 . 5

2 . 6

2 . 8

2. 5

2.9

(3

=

0

to

30

s /w= 1 . 5 to 4.0

A3 =

3 . 0

to 10. 0

m = 5 . 0

s/w= 3 . 0

Ai

= 5 . 0

p = 15

S/W

=

3 . 0

(3

=

1 5

All nozzles were designed to have the same physical exit area as that of

the three-inch-diameter circular nozzle. The four-element suppressor nozzles

were designed with internal contours which provided similar cross-sectional

area distributions as shown in figure 4. A l l nozzles, except Nos. 1.1 and 1 .3 ,

were fabri cate d of stainless steel for dimensional stability at the

1 2 0 0 ° F

exhaust

gas temperatures. Circular nozzle No. 1. 1 was fabricated with thick walls of

mild steel, and distortion did not appear to be a problem. However, thermal

distortion and failure of a weld occurred with the twelve segment nozzle, and

only

a

limited number of tests we re conducted.

The fuselage incorporated large orifices on the Ifupper side of the fuselage

which would permit ambient air to flow from the upp er fuselage s urface into th e

fuselage cavity; for some of the tests these orifices were covered with solid

plates to prevent the flow of ventilating

air

through the fuselage. The lower

sur fac e of the fuselage also incorporated removable plates which permitted

varia tion in the clearance between the nozzle and the lower surface of the

fuselage. With these plates, clearances of 0 0 . 5 , and 1.

5

inches were tested

with circular nozzle 1.1 and suppressor nozzles 2 . 1 and

2.5.

Combining varia-

tion of lower fuselage cleara nce space with up per fuselage ven tilation opening s

provided six fuselage and nozzle configura tions; of these, the two extrem e con-

figurations were investigated in greatest detail; i. e. , sealed nozzle and fuselage

for minimum ventilation in one

case,

and maximum nozzle clearance with upper

fuselage open for maximum ventilation in the other

case.

The fuselage was

cons truc ted prim arily of aluminum, but the plates used to vary the clearance

between the nozzles and the lower fuselage surface were fabricated from stainless

steel. F o r the plates which reduced the clearance space between the nozzles

and fuselage to zero, a perfect seal was not achieved and spaces on the order

of

0.

02 inches existed between the nozzles and the fuselage at some points.

8



Nozzle Test Rig

A schematic of the

test

faci lity is shown in fig ure 6. Additional details of

the instrumentation are shown in figure 7, and photographs of the rig and

in-

strumentation

are

shown in figure 8.

A s

in the Phase

I

tests,

the nozzle mod els were installed on

a

bellmouth

transition section

at

the end of a twenty-inch inside diameter plenum chamber.

Three internal baffle plates and a sc reen were used to provide unifo rm flow at

the entrance to the bellmou th section. The plenum was suspended by mea ns of

four flexures which minimized resistance to fore and aft movement. Thrust

loads were balanced only by the strain -gaged thrust rin g and a small force

resulting from deflection of the flexible inlet air pipe. Direct calibration of the

installed strain-gage d thrust ring by means of dead weights effectively isolated

nozzle th rust force s from a ny mec hanical lo ads imp osed y the inlet air pipe

and other service connections.

Airflow was measu red with an ASME l ong r adiu s flow noz zle upstre am of

the air preheater , and

a

dual valve arrangem ent permitted a constant Mach

number to be maintained through the flow nozzle . Filte red air for the noz zle

tests was obtained from a laboratory supply system at approximately

70

F with

a dew point of -40°F or less. For hot gas testing a propane-fired preheater was

installed upstream of the plenum chamber.

Pressure measurements in the jet wake were obtained with a remotely-

controlled Pitot-static probe which could be trave rsed along ea ch coordin ate

axis

of the model . Pressures

were

sensed by mean s of tra nsdu cers . Press ures

obtained in wake surveys we re recorde d directly as a function of probe pos ition

on Moseley

X Y

plot ters; other pressure data were recorded ei ther manual ly or

automatic ally on IBM punch c ard equipm ent.

Temperature measurements in the jet wake were obtained with

a

forty-one

element chrome l-alumel thermocouple rake installed on the ma st of the probe

traversing me chanism ; the thermocoup les were of the shielded stagnation type

shown in figure

7.

For the hot gas

tests,

operating conditions were based upon

the ma xim um tem pera ture found with the forty-one element thermocouple rake

when positioned

at

the nozzle exit plane; this nozzle discharge temperature was

then maintained throughout the jet wake surveys or other tests by means of a

reference thermoco uple just upstream of the nozzle exit. For the 1 2 0 0 °F nozzle

discharge condition of the prese nt tests , the ave rage no zzle di scha rge tem pera -

tur e was found to be 1161°F.

A

thermal profile was present at the nozzle

exit,

apparently the resultof non-uniform temperature distribution generated within

the propane fired preheater.

A

24 inch by 36 inch translating ground plane

was

instrumented as shown

in figures

7

and

8

to measure pressures and temperatures

at

the surface. Pres-

sure and temperature surveys in the boundary layer above the ground plane were

obtained using traversing five-element total pressure and stagnation tempera-

tu re ra ke s of the type shown in figure

7.

Surveys along the major and minor

9



axes were o btained by rotacmg the nozzles (and fuselage when used)90 degrees

at a quick-disconnect nozzle flange.

Data Accuracy

Repeated calibrations and checks on the

rig

instrumentation and read-out

equipment were made during the program, and it

is

believed that all data, with

the exception of the temperatures, were accurate within f 0.5 per cent of full

scale values. Temperatures were repeatable within

f 15 F , o r

in the

case

of

differential temperature ratios,

f 1

0 per cent. Shielded thermocouples were

used, where possible, to minimize radiation effects at the thermocouple junctions,

and it

is

believed that the accurac y of these readings was within f 2 . 0 per cent

of

f u l l

scale value

RESULTS

Method of Data Presentation

Because of uncertainties a ssociated with static pressure measurements

in an intensely turbulent stream, all dynamic pressure measurements are pre-

sented as differentials between indicated probe total pressure and atmospheric

pressure . S ta t ic pressures are presented

as

differential pressures with respect

to atmosp heric pressure s. Presentatio n of dynamic pressure data in this form

introduces effects of co mpress ibility, but the treatmen t is consistent with

.previous investigations. The use of dimensio nless ratios further minimizes

poss ible er rors due to compress ibi l ity effects. Sign conventions have been

taken

as

posi t ive for values where the measured pressure was greater than

atmospheric, and negative when the pressure was less than atmospheric.

In the c ase of dynamic p ressures d etermined w ith respect toa ground

surface, it has been found advantageous in some analy ses to use the differential

pressure between total pressure measured above the ground anda local s tat ic

pressure measured at the su rfac e of the ground plane, rather than a differential

between the total pressure above the ground plane and atmospheric. Wherever

this procedure has been followed, the resultant dynamic pressure has been d es-

ignated as a local dynamic pressure, to distinguish from dynamic pressures

referenced to atmospheric pressure. Data obtained for the tests in ground

effect

have been presented in both form s; conseq uen tly, care must be used in

making comparisons between various sections or figures of this report.

10



Nozzle Performance Evaluation

Effective velocity and mass flow coefficients were determined for all

basic nozzles using unheated air;

a

typical test configuration is shown in figure

8a. Resul ts for the three Phase I nozzle configurations previously evaluated in

reference

1 a re

shown in figure 9a. Other results obtaine d in these tests have

been grouped according to the su ppressor no zzle design parameters of exit wall

angle

fj

aspe ct ratio of the elements A z and spacing to width ratio

S/W,

figures 9b, 9c and 9d.

It

may be seen from these resul ts that , in general , both

effective v elocitv and m ass flow coefficients incre ased with inc reasing n ozzle

pressure ratio. In genera l, effective velocity and mass flow coefficients de-

crease progressively with increasing

exit

wall angle, increasing aspect ratio of

the nozzle elements, and increasing spacing to width ratio. Howev er, the

mass

flow coefficients for nozzle 2.3 show a rev er sal of trend at low nozzle pressure

rat ios. This

effect is

believed to be related to internal flow separa tion due to

local high velocities and unfavorable pressure gradients associated with

xit wall

divergence angle fj

=

15 and the small exit

w a l l

convergence angle r

=

8.4 .

The other nozzles in this

series

(nozzle s 2.4, 2.5, and 2.6) had larger values of

exit

wall

convergence angle

r

,

thus providing more favorable pressure gradients

and lower velocities

at

any specified cross section prior to the nozzle exit .

Following evaluation of t he b asic noz zles , tests w e r e conducted with

nozzles Nos. 1. 1 , 2.

1, 2. 5 , 2.

6, and 2.

8

in conjunction with an unventilated

fuse lage , simi lar to that sho wn~ n figure 8c. The effect of a ground plane on

effective velocity and flow coefficients was evaluated in th is se ri es of test s.

Results obtained in ground effect and out of ground effect for both the basic

nozzle and the unventila ted fuselage config urations are shown in fig ure 10 for

nozzles Nos.

1. 1, 2.

1, and 2.5. These results indicate that effective velocity

coefficients were reduced by either the presenc e of

a

fuselage

o r

ground plane,

and largest reductio ns were found when the fuselage and ground plane were tested

together. These effects

are

caused by reduce d static pressures acting over the

pr oje cte d are a of the fuselage and plenu m, rather than chang es in the effective

velocity coefficient of the bas ic noz zles .

N o

significa nt effects upon m a ss flow

coefficients

were

noted for any configuration of fu selage or ground plane evalua ted

in the present program.

The effects of variation of the clearance between the nozzle exit and fuselage

lower surface upon thrust wer e evaluate d for

two

conditions of fuselage cavity

ventilation; i. e.

,

upper fuselage inlets were ei ther both open or both closed.

The resul ts for tests out of ground effect a r e shown in figure 11, while results

obtained in ground effect

are

shown in figure

12

for the circular nozzle 1. 1 and

suppressor nozzles

2 . 1

and 2.5. These results indicate that increased clearance

between the nozzle and fuselage im proves effective velocity coefficient, while

ma ss flow coefficients remain essentially unchanged in all cases . Larges t

benefits of clearance between the nozzles and fuselage were obtained with the

suppre ssor nozzles, and it was found that

a

clea ran ce of

0.5

inches

was

nearly

as

effective as a cle ara nc e of 1 .5 inches. Ventilating the fuselage cavity

re-

sult ed in only minor improvement in effective velocity coeffic ients.

1 1



Similar, but

less

extensive, data were obtained for suppressor nozzles

2 . 6

and

2.8,

f igure 13.

In

this figure, the

effect

of the ground plane upon

effective velocity and mass flow coefficients

is

shown for two fuselage config-

urations; namely, (a)non-ventilated fuselage cavity with no clearance between

nozzle

exit

and fuselage lower surface, and (b) vent i lated fuselage cavi ty with

maximum clearance of 1 . 5 inches between the nozzle exit and the fuselage lower

surface.

The

first configuration of fuse lage described in

(a)

is

designated

as

the non-ventilated fuselage, while the second configuration of fusel age descri bed

in (b) is designated as

a

ventilated fuselage. These designations will apply to

f igure 13 and all subsequent figures of thi s re po rt in which

effects

of fuselage

configuration are being presented. Although testing only two fuselage config-

urations with each n ozzle of intere st eliminates some fus elage/noz zle inter-

actions, it was felt that the two extremes of fuselage/nozzle clearance and cavity

ventilation would bracket reasona bly well the range of

effects

which would be

encountered in practical applications.

From the results shown in figures 9 through 13, it is apparent that overall

thrust

of

the various nozzle and fuselage configurations

is

influenced significantly

by

(1)

nternal nozzle geometry,

(2 )

fuselage to nozzle clearance, and

(3)

prox-

imity to a ground surface. Additional results which may be of as si st an ce in

further evalu ating these factors will be pre sented in subsequent sections of this

report .

Fr ee Je t Wake Surveys

Typical results of p res sur e sur vey s of four-element suppressor nozzles

are shown in figure

14

for nozzle 2.1. The data obtained from the surveys of

the jet wake of several basic n ozzles were cro ss-plotted as shown in figure 15

in order to provide contour maps of dynamic pressure and differential tem-

perature, along the major axes of the nozzles. From these plots, the relative

rate of mixing of the va rious jet wake s is readily apparent, as are the sub-

sequent g rowth an d mergin g patterns of the jets from each discharge opening of

the multiple-e lement suppress or nozzles. The point at which merging of these

individual jets occurs is largely de termined by the spacing between the nozzle

elements. Becau se the relative rate of mixing of the ove rall jet wake is also

strongly influenced by the me rg ing char act eri sti cs of the individual jets,

it

is

apparent that spacing between the nozzle elements is an important factor in

determining the pressur es and tem peratures im posed upon a ground surface

during

VTOL

aircraft operations.

Maximum values

of

dynamic pressure and differential temperature in the

jet wake at selected dis tances do wnstream of the nozzle exit a r e shown in

figures 16 and 17 for e ach of the basic nozzles tested. Maximum values of

dynamic pressure and different ial temperature, rather than average values, have

been used as a crite rion of e rosio n char acter istic s of the nozzles by other

investigators and, as shown in reference 5, correlation between maximum values

of jet wake d ynamic pressure and e rosion c haracteristics of various ground

12



surfaces has been obtained experimentally. In addition , the maximum values of

dynamic pressure and differential temperature provide a valid indication of the

rapidity of mixing of the entire jet, inasmuch

as

the ce ntra l regi ons of the jet

will be the last regions to be affected by the shear generated turbulenc e origi-

nating

on

the perimeter of the jet.

The data of figures 16 and 1 7 show that the suppressor nozzles produced

significantly

greater

decay of the pressures and temperatures in the jet wake,

compared with the decay characteris tics of the circ ular noz zle. The suppressor

nozzles

were less

effective in reduc ing differential temp eratures in the jet wake

than in reducing dynamic pressures . The differences in jet wake degradation

cha rac ter ist ics shown in figures 16 and 17 for nozzles

2 . 3

and 2.4

are

due to

diff eren ces in the mer ging of the individual

jets.

Differences in the jet wake deg-radation cha rac ter ist ics of th e vari ous

nozzles at discharge temperature s of 70°F and 1200°F may be determined also

from the data of

figures

16a and

16b.

In general, the decay of th e jet wakes

occurred more rapidly at the higher nozzle discharge temperatures , with the

largest changes found in tes ts of the circular nozzle. The effect of tem per atu re

upon the dec ay chara cteristics of the suppressor nozzles is similar to that of

the circular nozzle, but

is

much less evident beca use of the masking effec t of

the high mixing rates inherent with the suppressor nozzle configurations.

Results obtained from surveying the jet wake dynamic pressures and

tem per atu res in various locations removed from the central axes of the nozzle,

figu re 18, show that the two outer jets of the fo ur slot suppressor no zzles decay

much more rapidly than the two inner jets. The results of figure 18 indicate

that total pressures less than am bient w ill be found in the regions between the

individual nozzle discharge elements. These negative pressure regions represent

a thrust loss which can not be separate d from the internal flow losses with the

test

rig force measurements obtained.

Fuselage and

Ground Plane

Effects

Figure 1 9 shows maximum values of the dynamic pressure ratio and

differential temperature ratio on o r above the ground plane for various nozzle

and fuselage configurations. The dynamic pressure and differential temperature

degradation curves for the basic nozzles provide

a

comparison with mixing rates

previously determine d in the free jet

tests.

For the circular nozzle, values of

pressures and temperatures over the ground surface were less than measured

in the free jet wake at Z/De

= 5.

Conversely, values of pres sure s and temper a-

tures over the ground surface were somewhat higher for the suppressor nozzles.

For th e dis tance of five nozzle diameters maintained between the ground surface

and the nozzle exit in the present tests, the results indicate that the ground

plane did not greatly disturb the degradation of the jet wake prior to impingement

with the ground surface.

Additional res ults obtaine d from the dynamic pressure a nd differen tial

temperature surveys over the ground plane are shown in figures 20 and 21. The

dynamic pressure profiles (ref erenced to ambien t pressure ) of the suppressor

nozzles are sm all er in value and show less variation with height above the ground

13



than do the profiles produced by the circular nozzle. This result is attributable

to the

greater

mixing in the jet wakes of the supp ressor nozzles. The values of

dynamic pressures and different ial temperatures over the ground plane were

slightly higher in tests of the basic nozzles, compa red with non-ven tilated fuse-

lage and nozzle configurations. Surveys over the ground plane indicated that

larger valu es of dynamic pressu re were pres ent along th e major

xis ( x

axis ) of

the nozzles and fuselage than along the minor axis

( Y

axis).

A

similar

but much

smaller effect of nozzle and fuselage orientation with respect to the ground plane

was observed in the different ial temperatures measured in the jet eff lux over

the ground plane. Because

effects

of orien tatio n were obs erve d in

tests

with and

without the fuselage,

it

is believed that these effects

are

related to nozzle geom-

etry.

Some of th e dyn amic p ress ures m easu red in th e surv eys of the efflux over

the ground plan e were found to be lower than the static pressures measured on

the surf ace of the ground plane at corresponding radial locations from the center

of the ground plane; these data have been indicated by hrolten lines in fig ure s

2011 and 20c. It is believed that these data are an indication that the efflux over

the ground plane

at

these locations was flowing radially toward the center of the

ground plane rather than radially away from the center of the ground plane.

Mclial inflow direc tion over the ground plane may be caused by merg ing of the

jets impinging at points not located at the c en ter of the ground plane. Further

evidenc e of this behavio r may be seen in the free

jet

wake survey s of nozzle

2. 1, figure 14a.

Con tour maps of

static

pressure coefficients and local gas temperatures

on o r immediately above the ground plane are presented for the circular nozzle

and suppressor nozzles 2 . 1 and 2. 5 with non-ventilated fuselage configurations,

f igure 22. These data were obtained using the instrumented traversing ground

plan e, deta ils of which

are

shown in figures

7

and

8b.

The contours obtained in

the

circular

nozzle

tests

were n early sym metrical w ith respe ct to the center of

the ground plane, but the contours developed for the suppressor nozzles con-

tained dist inct islan ds of high

static

pressures displaced 1. 0 to 1. 5 nozzle

dia me ter s fro m th e ce nte r of the ground plane.

A

larg e regi on of nearly uniform

temp eratu re was found

at

the ce nter of the ground plane during the suppres sor

nozzle tests.

While it is difficult to obtain meaningful measurements near the point of

jet impingement, it

is

believed that some useful interpretation of the flow field

may be made from the difference between total pressure measurements just

above the ground plane boundary layer and the

tatic

pressures measured on

the su rfa ce of the ground plane. Figure 23 shows the radial distribution of

maximum ocaldynamicpressures

(q

/qn) long hemajor ndminor

gs max

axes of the ground plane, together with the corresponding radial variation of the

maximum different ial temperature rat ios (t

/Til). For the circular nozzle,

figure 23a, the local dynamic pressure is very low nea r t he ce nt er of the ground

plane. The loca l dyn amic pres sure incr ease s to a maximum at approximately

one diame ter from the center , and then decrea ses in an exponential manner Ivith

radi al dista nce beyond that point. The radial distribution of masimum differentia l

g max

14



temperature above the ground p lane exhibited highest values t the cen ter of the

ground plane, and these values decreased non-linearly with radial distance from

the center .

Local dynamic pressures over the ground plane in the suppressor nozzle

tests

acted in a manner similar to that of . the circular nozzle; however, the

highest values were found

at

radial distance s of 1 .5 t o

2.

0

nozzle diameters

from the cen ter of the ground plane. These results

are

due to merging charac-

ter is t ics of the jets ,

as

noted above for figures 20b and 20c. The negative

values of local dynam ic pressures in figu res 23b and 23c are also an indication

of th e radi al inflow toward the center of the ground plane. Survey s paralle l to

the major and minor axes of the suppress or nozzles and fuselag e ( X and Y axes)

show

that higher values of the iocal dyna mic pressu re and different ial temper-

a tdre ra t ios are found along the major axis, both with and without fuselage;

consequently, it was concluded that the primary factor which produces the effects

noted is nozzle geometry.

The radial distribution of flow from the point of impingemen t of a ci rc ul ar

jet

has been investigated in ref erences 5 and

G

and results similar to that shown

in figure 23a were obtained. However, the nozzles used in these investigations

exhibited differences in the

jet

core length which were reflected in differences

in the magnitude of lo cal dynamic pressu res measured over the ground surfa ce.

It has been suggested that the distance from the end of the jet core to the ground

plane constitutes

a

refe renc e param eter of jet wake mixing characteristics.

Figure 24 shows the correlation between the results of r efer enc es 5 and 6 and

the present tests .

Figure 25 shows the distribution of sta tic press ure coef ficie nts over the

lower fuselage surface, while figure 26 shows the variation of these fuselag e

static pressu re coeffic ients with distanc e radially from the nozzle exit. In-

creased s ta t ic pressure di f ferent ia l s (p

-

p

)

w er e found in ground effect.

Largest static pressure differentials were found to occur very near the nozzle

exit. These differentials were both large and non-uniform in the region between

elemen ts of the suppre ssor nozzles . Static pressure differen tials found between

outermost suppressor nozzle elements were much larger for nozzle 2 . 5 than

2 . 1 ,

indicating a strong influence of wall divergence angle upon loc al jet ent rain -

ment. The largest values of static pressure differentials were located near the

outer ends of the suppressor nozzle elements,

as

indicat ed by the islands in

figu re 25. The static pressure differentials between the outermost nozzle

elements were larger than the corresponding stat ic pressure different ials be-

tween the two most centrally located elements.

Sf

0

Temperature distributions on the lower fuselage surface

are

shown in

figu re 25. Measurements were made with the ground plane

at

a di sta nc e of five

diameters from the nozzle exi t . A t the nozzle discharge tempera ture of 1200 F,

tempera tures on the fuselage were less than

200

F.

1 5



DISCUSSION

Free Jet Cha racte risti cs of Basic Nozzles

In order to be effective , suppressor nozzle designs must substantia l ly

reduce the dynamic pressures and temperatu res of the

jet

wake prior to im-

pingement on the ground surface. A primary consideration in the program

has been the evaluation of those fact ors which co uld alter the m ixing

rates

in

the jet wake. The objective of Ph as e

II

of the program has been the evaluation

of VTOL nozzle desig n parameters and con figuratio ns which prom ise significan t

reduction of the dyna mic p ressu res and t emp erat ures im pose d upon

a

ground

surface, consiste nt with minim um thrust reduction . The effects of a fuselage

and of a ground plane upon jet mixing and nozzle thrust were investigated.

Effects of nozzl e wall discharge angle, discharg e aspect ratio, and spacing

to width ratio upon dynamic pressure and differential temperature degradation

of free jets of t he basi c nozz les are shown in figures 27 and 28. The gains due

to increasing nozzle wall divergence angle and aspect ratio are shown to be

minor, except

at

small distances from the nozzle exit. Variati on of the spacing

between the nozzle elements was found to be an important parameter in det er-

mining jet wake degradation (figures

27

and 28); maximum degradation was

achieved with the largest values of the spacing ratio.

Data obtained from the jet wake surveys were used to determine the

rate

of sp re ad in g of the

jet

wake and the progre ssion of the mi xing proc ess in a

manner simila r to that used in the Phase I tests, reference 1. By non-dimen-

sionaliz ing the respective dynamic pressures and dif ferentia l temperatures

against selected reference values, it was possible to collapse the dynamic pres-

sure and dif ferentia l temperature dis tr ibutions across the je t wake onto

universal profiles as shown in figure 29. Th e res ul ts pre sen ted in fig ure 29

indicate that the shear-generated turbulent mixing processes remain generally

similar throughout the fully developed

jet

wake region. However, the rate of

spreading of the jet appears to be influenced by factors related to nozzle geom-

etry, and the general observation may be made that those jets which spread

most rapidly also decay most rapidly with distance from the nozzle exit. Be-

caus e of the interrelationship between nozzle geometry and the subsequent

sprea ding ch aract erist ics of the jet wake from suppressor nozzles, methods

of predicting the location of the refer ence dy nam ic pres sures an d diffe rent ial

temperatures appear to be less than sat isfactory

at

this t ime.

In order to inve stig ate changes in the mechan ics of mixing

as a

function of

nozzle design, the maximum dynamic pressure ra t io at seve ral loca tion s down-

strea m from the nozz le exit f each basic nozzle was compared with the max-

imum differential temperature ratios at corresponding locations, figure 30a.

Maximum values of dynam ic pressure s and te mperature s maint ain a well es-

tablished relationship along the jet for all nozzle configurat ions in which merging

between individual jets does not occur. Figure 30a shows that temperature

1 6



degradation lags dynamic pressure degradation in the fully developed mixing

region of the jets. For jets in which merging occurre d, the decay of differential

temperatures was inhibi ted to a grea ter deg ree than the dec ay of dynamic pres-

sures. Turbulent energy dissipation continues during the merging process, but

only small amounts of external air can enter the mixing zone between the jets to

reduce the temperatures.

Figure 30b shows that the distance from the nozzle exit

at

which

a

specific

rat io of dynam ic pressure to differentia l tempera ture occurs

is

distinctly

different for various basic nozzle configurations. The suppressor n ozzles,

becaus e of the rapid rates of dynami c pressure degradatio n achieve d, quickly

rea ch ra tio s of dynamic pressure to differenti al tempera ture which correspond

to simi lar ratio s found much farther downstream in the

jet

wake of a circular

nozzle. The principal effect achieved by the suppressor nozzles

is

a compression

of the distance scale in which the mixing occu rs.

Comparisons of the

free

jet maximum dynamic pressure and differential

tempera ture deg radation of the various nozzles with that of the circ ular noz zle

have been made in figur e

31.

The se curves were determ ined by finding the

differences between the respective quantities for the suppressor and circular

nozzles for various distances downstream from the nozzle exit . These curves

repr esen t an incr eme ntal gain (in term s of nozzle exit values) which can be

obtained by use of eac h su ppresso r noz zle as contrasted with that of the circ ular

nozzle. It

is

seen that gains on the orde r of

70

per cent in dynamic pressure

reduction and 50 pe r cent in different ial tempera tures may be obtaine d by using

suppressor nozzles. For the nozzles tested, maximum gains occur

at

approx-

imately five to six nozzle diameters from the exit. Becaus e of the nature of the

circular nozzle degradation curve, the distance from the ground surface for

maximum gains will always occur in the range of four to six equiva lent circula r

nozzle diameters.

Data from figure 31, when combined with the effective velocity coefficients

of ea ch nozzle, can be used to show the trades between jet wake degradation

characteristics and nozzle thrust performance. Figure 32 shows the trades for

a

distance of five equivalent nozzle diameters from the nozzle exit. The results

indicate that dynamic pressure and differential temperature degradation

are

nearly independent of nozzle thrust coefficient. Maximum degradation with

minimum thrust losses were achieved with nozzles 2 . 1 , 2 . 2 , 2 . 6 , 2 . 8 , and 1 . 3 ,

and

it

was found that b est re sults f rom the Ph ase I1

tests

correspond well with

the best

results

of the Phase

I

tests. It should be noted that thrust losses were

largest with nozzles 2 . 7 , 2 . 9 , 2 . 3 , and

2. 5, i. e. ,

nozzles with large wall

divergence angles ( 2 5 ), small spacing to width ratio (S/W = 1.5), and

high aspect ratio

(,qx

=

10).

Nozzle 2 . 4 showed somewhat better thrust performance than would be

anticipa ted on the ba sis of the perf orm ance of nozzles 2 . 3 ,

2.5,

and 2 . 6 . The

value of effective velocity coefficient shown for nozzle 2 . 4

in

figure 32 was

verified by sev eral check runs.

In

compa rison with the perform ance of nozzle

17



2 . 4 , nozzle 2. 3 exhibits a markedly lower effective velocity coefficient. The

low effective velocity coefficien t of

2 . 3

is at t r ibuted to large internal losses.

Consequently, it is possible to visualize nozzle designs with small spacing to

width ratios (i. e. , S/W < 2.

0)

which have high velocity coefficients. If a point

is

visualized with an effective velocity coefficientf approximately

0. 96

to

0. 97

instead of the

0 . 9 4

found with nozzle

2 . 3 ,

then the curve conn ecting nozzle s of

variable

S / W

in figure

32

would assume

a

shape s imi lar to tha tof the envelope

curve from the Phase I tests.

Fuselage and Ground Effects

The above discussion has summarized thrust and dynamic pressure de-

grad atio n charac teris tics of basic nozzles; other effects are introduce d when

the nozzle is installed in a fuselage and when operating in the proximity of a

ground surface. The principal effect, as shown in figure 33, was a reduction

in ava ilab le thru st of the combined nozzle and fuselage. Only minor change s

were noted in the jet wake degradation characteristics. These effects

are

pre-

sented for

a

nozzle height of five diameters from the ground.

A s

indicated by

references 2 and 3, the thrust losses would be expected to increase rapidly

with smaller distanc

s

between the nozzle and ground surface.

'i

The effect of fuselag e ventilation upon th ru st lo ss es in and out of ground

effect is shown in figure 34. These curves show that gains to be made by

ventilating the fuselage are relat ively insensi t ive to nozzle pressure rat io.

Maximum gain in effective velocity coefficient by ventilating the fuselage appears

to be about

2

to

3

percent for the suppressor nozzles, and

less

than

1

percent

for the single circular nozzle. Fuselage vent i lat ion is most helpful with nozzles

which have the greatest base pressure losses.

An unexpe cted result of the tests in ground effect

is

shown in figure

35.

The presence of a ground plane increased the suckdown losses by very nea rly

a

constant amount, regardles s of the nozzle o r fuselage ventilation. This loss,

which approximates

5

to 7 per cent of nozzle thrus t for all nozzle pre ssure

ratios, constitutes the largest single loss found d uring the tests. This loss

is

associated with large scale circulation under the fuselage, and can be minimized

by reduction of projec ted fusel age

area.

Thrust losses determined from static pressure measurem ents on the

fuselage

are

shown in figure 36 in and out of ground effect. Figure 36 shows

that base loss es of suppre ssor nozz les are concentrated largely in the regions

immedia tely adjacen t to the nozzles whe n out of ground

effect,

while large losses

are caused by

static

pressure reduct ions over the ent i re lower fuselage surface

when operating in ground effect. Large losses with suppressor nozzle

2 . 5

appear to be associated with a small fuselage area adjacent to the divergent side

of the noz zle. A s an explanation for this

effect,

it appears that increased tur-

bulence in the jet existed with nozzles having exit w all divergence, thus leading

to grea ter entr ainm ent of external air near the nozzle. To obtain a more

18



positive explanation of this beh avior w ould r equire extensiv e mea sureme nts of

the flow in the nozzle, as well as more comp lete surveys of the

jet

wake and

entrainment region near the nozzle exi t .

The results obtained in tests with various fuselage and nozzle configura-

tion s wer e found to

agree

with that of oth er inve stig ator s, refe renc e 2 . These

res ult s, with the ratio of projected mod el area to nozzle exit area

as

a

primary

pa ra me te r , a re shown in f igure

3 7 .

Although only a single large fuselage

was

used in the cu rrent tests , it is apparent from figure 37 that small fuselage

projected areas will be required to avoid significant suckdown effects, particu-

lar ly when operating in ground effect. Figure 37 also shows that fuselage

ventilation assists materially in maintaining competit ive effective velocity

coefficients for the suppressor nozzle configurations. Thrust losses due to

suckdown effects associated with suppressor nozzles vary from 0 . 5 to

2 . 0

per-

cent greater than those of the c ircular nozzle.

A summary of al l thrust losse s for the variou s nozzle an d fuselageon-

figurations are shown in figure

38.

The losses are shown to be cumu lative.

Nozzles which had greatest losses in the

tests

of the basic no zzles also ex-

hibited higher suckdown losses with the fuselage and ground plane.

CONCLUDING

REMARKS

Several exh aust nozzle mo dels design ed to achieve downwash s uppress ion

of the exhaust

jets

of

VTOL

aircraft have been evaluated for jet wake d egradation

and thrust chara cteristics with both hot gases and unheated

air.

For the best suppressor nozzle and fuselage configuration tested,

dynamic pressures were reduced by

GO

to

70

per cent, d ifferential

temperatures were reduced by nearly 50 per cent, and thrust losses

increased by less than 2 per cent compared with

a

reference circular

nozzle at five nozzle diameters above the g round surface.

A

l a rge thrus t

loss

resul ted from small negat ive pressure differen-

tials acting over the lower fuselage surface in ground effect, and this

loss was nearly constant for all nozzle configurations. This loss is

related to projected

area

of the model on the ground surface.

Jet

wake degradation characteristics were strongly influenced by the

merg ing cha ract eris tics of the multiple jets. Merging of the

jets

was

pri ma ril y rel ate d to the spacing between the nozzle elements. In-

crea sing the a spe ct ra tio of the nozzle elements was effective in in-

creas ing

jet

wake degradation. Increasing the exit wall divergence

angle was effec tive in increasi ng

jet

wake degradation for the region

less than three diameters away from the nozzle exit , but related

19



thrust losses resul t in an opt imum nozzle having smallxit wall

divergen ce angles, modera te aspect ratio of the elements , and a

large

spacing between the elements.

4)

Base area of the nozzle and fuselage immediately adjacen t to the

nozzle contributes significantly to the thrust losses with suppressor

type nozzles. Providing clearance between the suppressor nozzles

and fuselage was found to bean effective way to minimize these

losses. Ventilation , in the sense of providing

large

open areas

around the nozzle exit , will be necessary for best thrust performance

with suppressor nozzles. Openings on the upper fuselage surface

did not reduce thrust losses.

5)

A t

a distance of f ive diameters from the nozzle exi t , the ground

plane had only small effects upon jet wake degrada tion prior to

impingement. Effects of a fuselage upon the mixing processes

were minor,

Airplane Division, The Boeing Company

Renton,Washington

June 22, 1965

20



REFERENCES

1.

Higgins, C. C.

,

andWainwright,

T. W. :

DynamicPressureandThrust

Cha rac teris tics of Cold Jets Discharging from Several Exhaust Nozzles

Designed fo r VTOL Downwash Suppressio n. NASA T N D-2263,

April 1964

2. Gentry,Gar1 L.

,

Margason,Richard

J. ,

and Kuhn,RichardE. :

Jet-

Induced B as e Lo ss es on VTOL Configurations Hovering In and Out of

GroundEffect. NASA T N D-3166

3.

Spreemann,Kenneth

P.

,

andSherm an, rving R.

:

Effects of Ground

Proximity on the Thrust of A Simple Downward-Directed

Jet

Beneath

a

Flat Surface. NACA

TN

4407,

Septem ber 1958

4.

Davenport,Edwin

E.

,

.and Spreeman ,Kenneth

P.

: ThrustCharacter i s t ics

of Multip le Lifting

Jets

in Ground Proxim ity. NASA TN D-513, Septem be r

1960

5Kuhn,Richard. : An Inves tigation oDetermineConditionsUnder Which

Downwash from VTOL Aircraft will Start Surface Erosion From

Various Type s of Te rr ai n. NASA

T N

D-56, Septem be r 1959

6. Tani, tero,andKomatsu,Yasuo : mpingeme nt of

A

Round

Jet

on

a

Flat

Surface. Presented

at

Eleven th Internationa l Congress of Applied

Mechanics,Munchen,1964

21



(a)

CIRCULAR NOZZLE 1 . 1

(b) D E L T A NOZZLE

1.2

(c)

TWELVE SEGMENT

NOZZLE 1.3

Figure 1.

-

Phase I nozzles evaluated under phase 11.

22



NOZZLE 2.1

NOZZLE

2.4

NOZZLE 2.7

NOZZLE 2.2

. d.,...

NOZZLE 2.5

NOZZLE 2.8

NOZZLE 2.3

NOZZLE

2.6

NOZZLE

2.9

Figure

2.

-

Non-circular nozzle configurations

for

phase

11.

23



I

A, = N O Z Z L E E X I T A R E A . SQ.

IN.

Nozz le No.

A, L

W

2 . 1. 1 3 3 6

2 . 9 7 5. 5 9 5

2 . 2. 0 5 3 4

2 . 9 7 5. 5 9 5

2 . 3.11 9

2 . 9 7 5. 5 9 5

2 . 4. 0 3 0 0

2 . 9 7 5. 5 9 5

2 . 5. 1 1 5 1

2 . 9 7 5. 5 9 5

2 . 6. 1 4 6 5

2 . 9 7 5. 5 9 5

2 . 7. 0 4 0 7

2 . 9 7 5. 5 9 5

2 . 8. 0 6 4 0

2 . 2 9 8. 7 6 6

2 . 9. 0 9 0 0

4 . 2 0 0. 4 2 0

5

V

U P

1 . 7 8 5 1 . 1 4 4 1 . 2 5 0

0

1 . 7 8 5

1 . 0 5 3

1 . 1 5 0 5

0 . 8 9 2 5 0 . 5 6 7

1.000 15

1 . 1 9 0

0 . 7 8 5

1.000 15

1 . 7 8 5

0 . 9 1 5

1.000

15

2 . 3 8 0

0 . 9 4 3

1 .OOO I5

1 . 7 8 5

0 . 8 5 4 0 . 9 3 00

2 . 2 9 8 0 . 9 3 4 1 .OOO I5

1 . 2 6 0

0 . 8 4 7

1.000 15

r

2 5 O 2 7 '

27'2 1.5'

8 0 2 8 5

1 6 O 3 4 '

30 '45 '

4 1O 4 5 '

33 '28 '

3 7 0 2 7 '

22 '47 '

4

5

5

5

5

5

5

5

3

IO

s / w

3 .O

3

.O

1 . 5

2 . 0

3

.O

4 . 0

3

.O

3 .O

3

.O

Figure 3

-

Four-element suppressor nozzleconfigurations

24



BELLMOUTHNSTRUMENTATIONRANSITION

SECTION

1 .o

.8

.6

m

3

I

z

U

x

W

Q -4

.2

0

E L L I P T I C A LO Z Z L E

0 4

8 1 2

T

DISTANCE FROM PLENUM

-

INCHES

Figure

4

- Typical four-element suppressor nozzle cross-sectional

area and Mach number progression

25





T R A V E R S I N G

C/A RAKE

q

T R A V E R S I N G

PROBE

OTAL PRESSURE R A K E 2)

G R O U N D P L A N E

7

Figure

6 -

Schematic

of

test

r i g

and facilities



-

( a )

TRAVERSINGPITOTP R O B E

S U R F A C E T H E R M O C O U P L E

(TYP.)

SURFACE STATIC PRESSURE

(TYP.)

-0.125

X

0.028 W A L L

0.0625

C-A MEGAPAK

1

5

' H+.0

c )

FORTY-ONE ELEMENT TRAVERSING T H E R M O C O U P L ER A K E

( P R E S S U R E T U B E S A N D T H E R M O C O U P L E S I N T E R C H A N G E A B L E )

24.75' OD; 20" ID

P L E N U M C H A M B E R

\ N O Z Z L E

55.5 L 7 2 . 7 5 d - 3 7 4

T R A V E R S I N G J E T

WAKEPROBE

G R OU N D P L A N E

M O V E A B L E G R O U N

P L A N E (56

IN.

DIA .

I

Figure 7

- Schematic of

test

ri g and instrumentation

28



(a

TEST RIG (b) TRAVERSING GROUND PL AN E

( c )

CIRCULAR NOZZLE WITHON- ( 4 NTERIOR OF FUSELAGE

VENTILATED FUSELAGE

( e ) N O Z Z L E

2.5

WITH VENTILATED ( f ) N O Z Z L E

2.5

WITH INSTRUMENTED

FUSELAGE FUSELAGE

Figure

8. - Photog raphs of test

rig

for various nozzle and fuselage configurations

29



1 oo

U

6

e- .96

w

u

.92

I

Z

U

U

W

U

>

U

.88

>

W

e

1

$

84

W

U

.80

1 .o 1.2

1.4

1.6

NOZZLE

CONFIGURATION

1.1

CIRCULAR

.2

D E L T A

5 t R , 5 " f l

.3 TWELVE SEGMENT

1.8 2.0

a )

PHASE I NOZZLES

i

I

-

-

2.4

.6

Figure 9

-

Variation of effective velocity and mass

flow

coefficients

w i t h

nozzle pressure ratio for all basic nozzle configurations

30



1 .oo

V

.96

c'

z

I

W

>

w

L

.84

LL

w

.80-

1 .o

1 .ocJ

.96

V

LL

I--

z

W

.52

-

LL

LL

W

V

g .88

LL

m

.84

.a0

NOZZL

1.5

1.2

NO.

-

.

--

-:;.6

N O Z Z L E f i

2.1

0"

2.2 5"

2.5 15"

2.7

30"

L

1.8

2.0

2.2 2.4

2.6

N O Z Z L I

2.1

2.2

2.5

'

/

2.7

.

1.2

S A V =

3.0

t, =

70°F

= 5.0

n

2.0 2.2 2.4 2.6

NOZZLE PRESSURE RATIO, pt /p,

n

(b) PHASE

I I

N O Z Z L E S - V A R I A T I O N OF E X I T W A LL A N G L E , I¶

Figure 9

-

Continued

31



1 .oo

.96

.92

.88

.84

.80

1 .o 1.2 1.4

1.6

N O Z Z L E 4

2.8 3

2.5

5

2.9 10

_

1 .o 1.2 1.4

i

1.8 2.0 2.2

P

= 15"

S

W

=

3.0

tt, 70°F

1.6.8 .o 2.2

2.4.6

NOZZLE PRESSURE RATIO,

p ,/Po

c ) PHASE II

N O Z Z L E S

- VARIATION OF ASPECTRATIO,

A

2.4.6

Figure 9 - Continued

32







6

+-

w

u

Z

U

U

W

U

>

V

W

_1

>

W

+

U

W

U

U

W

k

?

I .oo

.96

.92

.88

.84

.80

1 oo

.96

V

U

e

w

u

.92

Z

U

L L

W

U

.88

U

v

In

Q

I

.84

.80

+.

I

.o 1.2.4.6.8

2 . 0.2.4.6

- - - - - - - -

BASIC NOZZLE 2.1 IN GROUND EFFECT (Z'D,

=

5.0)

O Z Z L E

2.1

WITHNON-VENTILATED FUSELAGE OUTOF GROUND EFFE CT

BASIC NOZZLE 2.1 OUT OF GROUND EFFE CT

N O Z Z L E

2.1

WITHNON-VENTILATEDFUSELAG E N GROUND EF FEC T (Z'D, =

5.0)

2 . 4

NO ZZ LE PRESSURE RATIO, pt,'p,

(b)

SUPPRESSOR NOZZLE

2.1

WITHFUSELAGEAND GROUND PLANE .

Figure

10

-

Continued

2.6

35



U

6

I--

w

u

Z

LL

W

U

U

>-

U

E

9

W

>

W

I

V

W

LL

U

W

1

1

.oo

.96

.92

.88

.84

.80

1 .o

1.2

1.4 1.6.8.0 2.2 .2. 4.6

BASIC NOZZLE 2.5 OUT OF GROUND EFFEC T

-

- -

- - - BASIC NO ZZLE 2.5 IN GROUND E FF EC T (Z.'De = 5.0)

O Z Z L E 2.5 WITH NON-VENTILATEDFUSELAG E N GROUND EFF EC T (Z'De

=

5.0)

- - N O Z Z L E 2.5 WITH NON-VENTILATED FUSELAGE OUT OF GROUND EFFE CT

t = 70°F

t "

2.4 2.6

NOZZLE PRESSURE RATIO, ptn/Po

( C ) SUPPRESSOR NOZZLE

2.5

WITH FUSELAGE AND GROUND PLAN E.

Figure 10

-

Concluded

36



1 .oo

U

s .88

W

>

W

I

>

-

Y .e4

LL

LL

W

.80

t

=

70°F

NO GROUND PLA NE

'"

N O C L E A R A N C E

- - - -

-

- -

INT ERMEDIAT E CLEA RANCE

AXIMUM CLEARANCE

N O Z Z L E N O .

1 .oo

.96

U

U

I

W

Z

E

.92

L L

U

W

U

v

v

4

I

.84

.80

1

.o 1.2 1.4 1.6 1.8.0 2.2 2.4 2.6

NOZZLE PRESSURE RATIO,

t+ /Fo

( a )

F U S E L A G ECAVIT YNOTVENT ILAT ED.

Figure 11 - Effect of clearance between fuselage lower surface and nozzle

ef i t on effective velocity and

mass

flow coefficients for nozzles

1. 1, 2. 1, and 2.5 out of ground effect

37



-

1

.o 1.2.4.6 1.8 2.0 2.2 2.4 2.6

=

70°F

' t "

NO CLEARANCE

MAXIMUM CLEARANC E

-

- - - - - - - - INTERMEDIATE CLEARANCE

O G R O U N D P L A N E

1

.o 1.2.4.6 I .a 2.0 2.2 2.4 2.6

NOZZLE PRESSURE RATIO, p t n / Po

(b l FUSELAGE CAVITY WITH MAXIMUM VENT ILATIO N

Figure 11

-

Concluded

3 8



1

.oo

.96

U

V

b-

W

z

g

.92

U

LL

W

V

g

.88

LL

_J

In

1

.o

1.2.4 1.6 1.8

I-

i

t t

1

70'F

Z De GROUND PLANE = 5.0

n

1

1 . 1

L

-2.1

~*

I

2.5

'

1

ZZLE NO.

ll

.2

2.0

2.2.4.6

rc

#

-

1.4 1.6 1.8.0

~~

NON-VENTILATED

VENTILATED

-

- -

-

- .

2.2.4 2.6

NOZZLE PRESSURE RATIO, pt /P,

n

Figure 1 2 - Effect of fuselage ventilation on effective velocity and ma ss

flow coefficients for nozzles

1.1, 2 . 1 ,

and

2 . 5

in ground effect



1 .o 1.2 1.4 1.6 1.8 2.0 2.2 2.4

2.6

NOZZLEONFIGURATION

2.6

2.6

V E N T I L A T E D

2 .8

V E N T I L A T E D

N O N - V E N T I L A T E D

2.8 NON-VENTILATED

- - -- - -

-

-

-

t = 70°F

1"

1 .oo

.96

.92

.88

.84

.@I

1 .o 1.2

NOZ ZLE PRESSURE RATIO,

p /p0

(a) OUTOF GROUND EFF EC T

t"

Figure 13 - Effect of fuselage ventilation on effective velocity and mass flow

coefficients for nozzles 2.6 and

2.8

in and out of ground

effect

40



1 .oo

.96

.92

.88

.ed

.80

1

o

1 .oo

.96

U

U

I--

.92

w

u

z

U

U

W

.88

V

3

-I

U

m

.84

.80

1

I _.4

z

"".1.6

-

t = 70°F

t"

1.8

1

.o

1.2.4 1.6 1.8

N O Z Z L E

2 . 6

2.6

2.8

2 . 8

-1

2 . 0

NOZ ZLE PRESSURE RATIO,

pt,/p0

2.2.4.6

CONFIGURATION

i

. i

NON-VENTILATED

2.4.6

(b)

IN GROUND EF FEC T C / D , = 5 .0 )

Figure

13

- Concluded

4 1



l~H

4

2

1

. o r

.4

-

.2

0

L

I I I

0

-4

-3

-2

- 1 0 1 \ 2

3

4

P+,/Po

=

2.0

ttn

= 1200" F

Y

Z/D,

-

0

.01

-

--.03

- .02

-.01

1

.o

0

-.01

J-.03

J-.03

-4

-3 -2

- 1 0 1 2

3

4

DISTANCEFROM

JET

CENTERLINE/EQUIVALENT CIRCULAR NOZZLE DIAMETER , X /De

( a

SURVEYS ALONG

X

AXIS.

Figure

14 -

Dynamic and

static

pressure surveys for basic suppressor nozzle

2.1

out of ground effect

4 2



P,"/P0 =

2.0

t t n = 1200" F

Z/D,

0

Y

x -

I

I

0

-

501

.2

-4 -3

-2 - 1 0

1

2 3

4

0

a

I

a

-.01

-.03 _

w

L L

w

U

J L

4.0

-.03

+

I

1 0 2

m

J -.OI

-I .01

-4

-3 -2 - 1 0 1

2

3

4

DISTANCE

FROM

JET CENTER LINE EQUIVAL ENT CIRCULA R NOZZLE DIAME TER, Y/'Do,

b) SURVEYS ALON G Y AXIS

Fi,gure 14

-

Continued

43

-



Y /

1.0

-

8

-

-7

.6

-

.4

-

.2

-

0

I I 1 I I I

P+,/Po

=

2.0

'tn = 1200" F

::Il

A

,

,

0

.2

0

I

.2

0

I

- 4 -3 -2 - 1

0

1 2

3

4

0 I

I

- -.01

- -.02

J

-.03

a

J -.03

"7

a

V

t

W

[II

8.0

I

I

10.0

- 1

~-

0

-

- -.02

-.01

-4

-3 -2 - 1 0 1 2

3 4

DISTANCE FROM JET CENTER LINE'EQUIVALE NT CIRCUL AR NOZZLE DIAMETER , Y/D,

( c ) SURVEY AT DISTANCE OF

0.90

INCHES FROM NOZZLE CENTERLINE.

Figure 14

-

Continued

4 4



.2

0 I I I J

.4

r

I l l

-4

-3 -2

-1 0 1 2 3 4

Z,D,

/ L I

1

.o

2 . 0

3.0

4.0

8.0

10.0

1

I I 0

-.01

I t I 0

-.01

-

.02

-

' - .02

-4

-3 -2 - 1 0 1 2 3 4

DISTANCE FROM JET CENTER LINE/EQU JVALENT CIRCULAR NOZZLE DIAMETE R, Y/D,

(d)

SURVEYS AT DISTANCE OF 1.80 INCHESFROM NOZZLE CENTERLINE


45



Y /

Ptn/Po = 2.0

t

-

12GW F

'n -

I

Z/D,

1

1 .o

.a

.6

.4

.2

0

a

. 2

0

I

I

I 1

.2

0

I

I I 1 I

- 4

-3

-2

1

0 1 2

3

4

8.0

I 1

10.0

-.02

I 1 1 - 0

-

- -.02

-.01

-4 -3

-2 - 1 0 1 2 3

4

DISTANCE

FROM

JET CEN TERL INE EQU IVALE NT CIRC ULAR NOZZL E DIAM ETER , Y/D,

( e )

SURVEY AT DISTANCE OF 2.70 INCHESFROM NOZZLE CENTER LINE

Fig-ure 14 - Concluded

46



4 6

8

10

12 14

16 180

0 2

4

6 8 10 12 14 168 20

AXIAL D IST ANCE F ROM NOZ Z LE EXIT /EQUIVALENT C IRCULA R NOZ Z LE D IAMET ER, Z 'D ,

b) TWELVE-SEGMENT NOZ Z LE

1.3

(Y = 0)

Figure

15 -

Jet

wake dynamic pressure and differential temperature surveys

of s everal basic nozz les out of ground effect

4 7





Y

W

N

N

W

z

3

2

1

0

1

2

3

3

2

1

0

1

2

3

4

I

X

-

I

1 2 3 4 5 6

7 8

9

10

( d )

SUPPRESSOR NOZZLE

2.1

(X

0.90

INCHES)

Ptn 'Po = 2 .0

tt,

:

200"

F

2 3

A X I A L D I ST A NC E F R O M N O Z Z L E E X I T / EQUIVALENT CIRCULAR NOZZLE DIAMETER, Z 'De

(e)

SUPPRESSOR NOZZLE 2.1 (X = 2.70 INCHES).

Figure 15

-

Continued

4 9



( f ) SUPPRESSOR N OZ ZL E 2.7 X = 0.90 INCHES)

t

i

I

I

L

7

A X I A L 9 l S T A N C E F RO M N O Z Z L E E X I T

/

EQUIVALENT CIRCULAR NO ZZLE DI . \METER, Z /De

(9) SUPPRESSOR NOZ ZLE 2.7 IX = 2.70 INCHES)

Figure 15 - Concluded



NOZ ZLE CONFIGURATION NOZ ZLE CONFIGURATION

m

s /w P RL S A Y A

5 3.0

0"

2.5

5 3.0

15"

5 3.0

5"

2 2.6

5 4.0

15'

5 1.5

15"

2.7

5.0

30"

5

2.0

15"

A

2.8 3 3.0

15"

0

NOZZLE CONFIGURATION

m

SAY D

L

2.9 10.05"

1.1 CIRCULAR

1.3 TWE LVE SEGMENT

1.2 D E LT A 5 a 5"

A

2

4 6 10 12 14

168

20

AXIAL DISTANCE FROM

N O Z Z L E E X I T / E Q U I V A L EN T C I R C U L A R N O Z Z L E

DIAMETER, Z/D,

i a ) NO ZZL E DISCHARGE TEMPERATURE = 70°F

1

0

2 10 12 1468

20

AXIAL DISTANCE FROM NOZZLE EXIT /EPUIVALENT CIRCULAR NOZZLE DIAMETER, ZID,

(b) NO ZZL E DISCHARGE TEMPERATURE

=

1200" F

Figure

16 - Jet

wake dynamic pressure degradation versus distance

from

nozzle exit fo r all basic nozzl e out of ground effect

51



1 o

.8

.6

.4

.2

I

NOZZLEONFIGURATION

.R s w B

2.1 5 3.0 0

0

2.2

5

3.0

5'

0

2.3 5 1.55'

x 2.4

5 2.0

15'

0 2.5 5 3.0 15-

2.6 5 4.0 15'

2.7 5 3.0 3 0

E 2 . 9 IO 3.0

1 5

A

2.8

3

3.0

15'

0 1 . 1

CIRCULAR

0 1.2

D EL T A 5R 5 /3

0

1.3

TWELVE SEGMENT

2 8

10

I

I

12

14

I

," 'Po = 2.0

t, = 1200"F

n

16

18

AXIA L DISTANCE FROM hOZZ LE EXIT ,' QUIVALE NT CIRCULA R NOZZLE DIAMETER, Z./D,

NOZ ZLE DISCHARGE TEM PERATURE = 1200°F

20

Figure 1 7 -

Jet

wake differential temperature degradation versus distance

from nozzle exit for all basic no zzles out of ground effect

52



1 .o

.8

c

0

\ x .6

e

LT

P

2

.4

a:

W

a:

3

v

v

W .2

a

u

a:

I

Q

E o

n

-.2

- .4

1.0

.8

.6

.4

.2

0

I

4

l l

I I I I

I

I I

"-

-

SINGLE ELEMENTHARACTERISTICS

4

6

8

IO

12 14

16

18 20

AXI AL DISTANCE FROM NOZZLE EXIT /EQIJ IVALENT CIRCULAR NOZZLE DIAMETER, Z/D,

(a) N O Z Z L E 2.1

Figure 1 8 -

Jet

wake degradation characteristics

for

several basic nozzle

configurations and survey planes

53



1 .o

.8

c

e

w .6

D-

c

+

Q

IL:

x

1

v

v

W

IL:

w

.4

a

u

I

Q

z

>

.2

n

0

- .2

-

4

54

E X T R A P O L A T E D F R O M P H A S

1 1

t," =

12"O"

F -

P+,/Po

=

2.0

--

b2

-

12

14

0

2

4

6 8

124

16

18 20

AXIAL

DISTANCE

FROM

N O Z Z L E

EXIT'EQUIVALENT CIRCULAR NOZ ZLE DIAM ETER ,

Z/D,

(b) N O Z Z L E 2.3

Figure 18

- Continued



1 o

.8

c

.6

8

G

2

m

I- .4

. I I - "

/--

1 - 1

1 I

I

I I

SINGLE ELEMENT CHARACTERISTICS

EXT R APO L AT ED FKUM PnASE

I

R

2 4 6 8 10

12

14 16 18

20

AXI AL DISTANCE

FROM

NOZZLE EXIT /EQUIVALENT CIRCULAR NOZZLE DIAUETER, Z/D,

c ) N O Z Z L E 2.5

Figure

18 -

Continued

55



~ I 1 1 1 1 1 1 1

SINGLE ELEMENT CHARACTERISTICS

EXTRAPOLATED FROM PHASE (REF. 1)-

PtPo

=

2.0

ttn

=

1200"

Ft

I

10

12

?

8

16

2

4

6

8 10

12

14

AXIAL DISTANCE FROM N O Z ZL E EXITIEQUIVALENT CIRCULAR

N O Z Z L E

DIAMETER, 20,

(d) NOZ ZLE 2.8


56





1 .o

.8

.6

.4

.2

0

0 2

4 6

8 IO

12 14

16

18 20

AXIAL

DISTANCE FROM NOZZ LE EXIT 'EPUIVA LENT CIRCULAR NOZZLE DIAMETER,

Z/D,

BASIC NO ZZL E OUT OF ;ROUND EF FE CT

""-

-

N O Z Z L E W I T H V E N T I L A T E DF U S E L A G E O U T O F G R O U b D E F F E C T

OZZLE WITH NON-VENTILATEDFUSELAGEOUTOF GROUND EFFE CT

FLAG

SYMBOLS

( r )

TAGNATION

PRESSURES

ON

OR

ABOVE SURFACE OF GROUND PLANE

BASIC NO ZZL E N GROUND EFF ECT (Z/D, =

5 .0 )

>

NOZ ZLE WITH NON-VENTILATED FUSELAGE N GROUND EFF ECT (Z/D,

=

5 . 0 )

a )

CIRCULAR NOZZLE

1 .1

WITH DISCHARGE TEM PERATURE

= 70"

F

'Figure 1 9

-

Effect of fuse lage and ground plane on jet wake degradation

characteris t ics

58



0

l a

12 14

16

18

20

AXI AL DISTANCE FROM NOZZLE EXIT'EQUIVALENT CIRCULAR NOZZLE DIAMETER, ZD,

BASIC NOZZLE

OUT

OF GROUND EFFECT

FLA G SYMBOLS

( r ) STAGNATION P R E S S U R E S

OR

DIFFERENTIAL TEMPERATURES

ON OR

A B O V E S UR FA CE O F G R O U N D P L A N E

BASIC

N O Z Z L E

IN

G R O U N D E FF EC T

Z/D, = 5.0)

> N O Z Z L EW I T HN O N - V E N T I L A T E DF U S E L A G E IN GROUND EFFECT (Z /D, = 5.0)

0 2

4 6

8 IO

12

14

16 18 20

AXI AL DISTANCE FROM NOZZLE EXIT./EQUIVALENT CIRCULAR NOZZLE DIAMETER, Z/D,

b) CIRCULAR NOZZLE 1 . 1 WITH DISCHARGE TEMPERATURE 1200" F

Figure 19

- Continued

59



0 2 4

6

a

1 0 12

14 168 20

AX IAL DISTANCE FROM NOZZLE EXIT 'EQU IVALEN T CIRCUL AR NOZZLE DIAME TER, Z/D,

B A S I C N O Z Z L E O U T O F S R O U N D E F F E C T

_

-

N O Z Z L EW IT H VEN T IL AT EDF U SEL AG EO U T O F G R O U H DEF F EC T

O Z Z L EW IT H N O N - VEN T IL AT ED F U SEL AG E O U T O F G R O U N DEF F EC T

F L AG SYMBOLS ( r ) TAGNATION P R E S S U R E S ON ORABOVE SURFACE

OF

GROUND PLANE

B A S I C N O Z Z L E IN G RO UN D EFFECT (Z/D, = 5.0)

> N O Z Z L E W I T H N O N - V E N T I L A T E D F U S E L A G E IN GR OU ND EFFECT (Z /D ,

5 .O)

( C ) SUPPRESSOR NOZZLE 2.1 WITH DISCHARGE TEMP ERAT URE 70" F

Figure

1 9

- Continued

60



0 2

\

102 14680

A XI A L D IST ANCE F ROM NOZ Z LE EXIT EQUIVALENT C IRCULAR NOZ Z LE D IAMET ER, Z *'D ,

BASIC NOZ Z LCOUT OFGROUND EF F ECT

FLA G SYMBOLS

ST AGNAT ION PRESSURES

OR

DIFFERENTIA L TEMPERATURES

(r)ON OR

AB OVE SURFACE

OF

G R O U N D P L A N E

/* B A S IC N O Z Z L E N G R O U N D E FFE CT ( Z/ D ,

=

5.0)

> N O Z Z L E W I T H N O N - V E N T I L A T E D F U S E L A G E N G R O U N D E FFE CT ( Z /D , = 5.0)

.

-~

2

4

6 8

10 12 1468 20

AXIAL D IST ANCE F ROM NOZ Z LE EXIT /EPUIVALENT C IRCULAR NOZ Z LE D IAMET ER, Z 'De

(d)

SUPPRESSOR NOZZLE

2.1

WITH DISCHARGE TEMPERATURE

1200"

F

Figure 19

- Continued

61



0

2

4

6

8

AXIAL DISTANCE FROM NOZZLE EXIT ’EQUIVALENT CIRCULAR NOZZLE DIAMETER, Z ID,

B A S I C N O Z Z L E O U T O F r J R O U N D E F F E C T

””- N O Z Z L E W I T H V E N T I L A T E D F U S E L A G E O U T O F G R O U K D E F F E C T

”

O Z Z L E W I T H N O N - V E N T I L A T E D F U S E L A G EO U T O F G R O U N DE F F E C T

FLAG SYMBOLS (r)

STAGNATION

P R E S S U R E S ORDIFFERENTIAL TEMPERATURES

ON OR ABOVE SURFACE OF G R O U N D P L A N E

f i

B A S I C N O Z Z L E IN G R O U N D EFFECT (Z /D, =

5.0)

N O Z Z L E WITH N O N - V E N T I L A T E D F U S E L A G E

IN

G R O U N D EFFECT (Z /D, = 5.0)

(e) SUPPRESSOR NOZZLE 2.5 WITHDISCHARGE TEMPERATURE 70” F

Figure

19

-

Continued

62



0 2 4 6

8

IO 12 14 16 18 2 0

AXIAL DISTANC E FROM NOZZLE EXIT 'EPUIVALENT CIRCULAR NOZZLE DIAMETER, Z/D,

BASICNOZZLE.OUTOF GROUND EFFE CT

FLAG SYMBOLS

0 2

ST AG NA TI ON PRESSURES OR DIFFERE NTIAL TEMPERATURES

( O N OR ABOVE SURFACE OF GROUND P L A N E

/*

B A S I C N O Z Z L E IN GROUND EFFECT (Z/D, = 5.0)

> N O Z Z L E W I T H N O N - V E N T I LA T E D F U S E L A G E IN GROUND EFFECT (Z/D, = 5.0)

8 IO

12 14

16

18

6 20

AXIAL DISTANCE FROM NOZZLE EXIT/EQU IVALENT CIRCULA R NOZZLE DIAMET ER, Z.'D,

( f )

SUPPRESSOR NOZZLE 2.5 WITH DISCHARGE TEMPERATURE =

1200' F

Figure 19

-

Concluded

63



WITHOUT FUSELAGE

.5

.4

.3

.2

.1

0

0 .2

.4

.6 .8 1

o

R 'De

-

0 0

.15

P+,/Po 2.0

n

.50

t tn =

1200" F

A 1.00 GROUND PL AN ET Z/D,

=

5.0

0

2.00

0 3.00

0

5.00

NON-VENTILATED FUSELAGE

.5

.4

.3

.2

. I

0

0 .2 .4

.6

.8 1 o

DYNAMIC PRESSURE RATIO OVER GROUND FL AN E,

qdq,

(a) C IR C U L ARNOZZLE 1.1

Figure 2 - Dynamic pres sure distributi on in the jet

efflux adjacent to the ground plane

64



WITHOUT FUSELAGE

.2

.4 .6

.I5

S O

1 .oo

2 .oo

3.00

5.00

Y AXIS

.a

1.0 0 .2

.4

.6

.a 1.0

- - - - -

-

- - CROSS FLOW CON DITION WITH R ESPEC T TO AXES OF PROBE


X AXIS

.2

.4

.6

.a

1.0 0 .2

Ptn /Po = 2.0

t t n

= 1200 F

GROUND PLANEAT Z/D,

5.0

I

AXIS

DYNAMIC PRESSURE RAT iO OVER GROUND PLAN E,

q d q ,

(b)

SUPPRESSOR NOZZLE 2.1

.6 .a 1 .o

Figure 20 -

Continued

65



X AXIS

.5

.4

'1

.3

d

W

+

w .2

I

4

D

W

J

N

N

.1

Z

Q

-

R De

n .50

. I 5

A 1.00

0

2.00

0 3.00

0 5.00

WITH3UTUSELAGE

Y AXIS

.8 1.0 0 .2

.4

. .

. -

.

.6

-

-

-

- - - -

-

CROSSFLOW COND ITION WITH RESP ECT

T O

AXES OF PROBES


XXIS

0

.2 .4 .6 .8

1.0

0

.2

.4

DYNAMIC PRESSURE RATIO OVER GROUND PL AN E, qq

c ) SUPPRESSOR NO ZZ LE

2.5

Pt,/Po = 2.0

t , = 1200" F

n

GROUND PLA NE AT Z/De =

5.0

-

.6

.8

Figure

20 - Concluded

66





.5

X AXIS

.4

.3

.2

1

E-

+

W

I

n

W

J

N

s o

5

z o

.2

.4

E

V

V

k

w

Z

J

E

P+"/P0

2 . 0

t t n = 1200" F

I

-

6

GROUND

P L A N E

A T Z / D = 5.0

W

Z

_I

Q

X AXIS

a

n .5

Z

E

w

>

.4

m

Q

W

V

Z

2 .3

n

.2

.1

0

0

2 .4 .6

-

8

WITHOUT FUSELAGE

-

.o

0

.2

.4


Y AXIS

~~

-~

~-

~~

. 2

DIFFERENTIAL TEMPERATURE RATIO OVER GROUND

PLANE,

tdT,

b ) SVPPRESSOR N OZ ZLE 2.1

.0 0

2

.4

.8

R 4

0

\ .oo

0

2.00

.50

3.00

0

5.00

.

..

L


68



.2

WITHOUT FUSELAGE

X AXIS

.4 .6 .a 1 .o

P," ,Po

=

2.0

t,

=

1200 F

n

GROUND PLANE AT

Z / D :

5.0

.2

X AXIS

.6

Y AXIS

.4 .6

.a

1

.o

R De

0 0

0 S O

A

1.00

0

2.00

0

3.00

0

5.00


Y AXIS

1.0

0 .2 .4

.8

1

.o

DIFFERENTIAL T E M P E R A T U R E RATIO O VER GROUND PLANE, t,p,

( c ) SUPPRESSOR NOZZLE 2.5

Figure

21 - Concluded

69



II - c,

I

Y/D,

I

I -

c

1 1 1 - TEMPERATURES, "F

IV -

TEMPERATURES, "F

QUADRANTONFIGURATION

I

AND

IV

N O Z Z L E

1 . 1

WITHOUT FUSELAGE

II AND

1 1 1

N O Z Z L E 1 . 1 WITH NON-VENTILATEDUSELAGE

P tn /P o 2.0

t tn

= 1200°F

Z/D, GROUND PL AN E

= 5.0

(a) C I R C U L A RNOZZLE 1 .1

Figure

22

- Distribution of surface stat ic pressures and exhaust gas

temperatures adjacent to ground plane for various nozzle

and fuselage configurations

70



I1

-

c,

t

I -

cp

-

1

I l l - TEMPERATURES, "F I IV - TEMPERATURES, "F

QUADRANTONFIGURATION

I AN DVOZZ LE 2.1 WITH NON-V ENTIL ATEDUSELAGE

II AND

1 1 1

NO ZZL E 2.5 WITH NON-V ENTIL ATEDUSELAGE

Ptn/Po 2.0

t tn

= 1200°F

Z/D, GROUND PL AN E = 5.0

(b) SUPPRESSOR NO ZZ LE S 2.1 AN D 2.5

Figure

22 -

Concluded

7 1



mm I WITHOUT FUSELAGE


Q

W

>

W

5 .4

m

m

W

D:

a

U

Q

Z

>

a

5 .2

I

IO

3

4

WITHOUT FUSELAGE

5

Pt,/Po

=

2.0

t t n = 1200 F

GROUND PL AN E AT Z/D,

=

5.0

3 4


0

1

2 3 4

DISTANC E FROM CENT ER OF GROUND PLANE/EP UIVALEN T CIRCU LAR NOZZL E DIArdETER , R/De

( 0 ) C I R C U L A RN O Z Z L E 1.1

5

5

Figure

23

- Radial distribution of maximu m dynamic pressures and

dif-

ferential temperatures in theefflux over the ground plane


72



1

1

WITHOUT FUSELAGE

2 3 4

5 0

WITHOUT FUSELAGE


X AXIS

Y AXIS

"

Ptn/Po

2 .0

t t n

= 1200" F

GROUND PLA rlE AT Z/D,

I5.0

3 4 5


.-I; .;

I : [11

~.

1 3

4

5

DISTANCE FROM CENTER O F GROUND

PLANE/EQUIVALENT

CIRCULAR N O Z Z L E DIAMETER, R/D,

(b)

SUPPRESSOR N OZ ZL E 2.1

Figure

23 -

Continued

73



WITHOUT FUSELAGE

N O N - V E N T I L A T E D F U S E L A t i E

1 2 3 4

n

5 0

1

2 3

4

5

X AXIS

Y AXIS

p t p 2.0

' t " = 12000F

GROUND PL ANT A T Z/De 5.0

WITHOUT FUSELAGE

DISTANCE FROMCENTEROFGROUNDPLANE/EQI


~~ ~-

0

1 2 3

4

5

UIVALEN T CIRCUL AR NOZZLE DIAMETER, R/O,

c ) SUPPRESSOR NOZZLE 2.5

Figure

23

- Concluded

74



h

i

0.5

De

CIRCULARNOZZLE 1.1 (Ptn/Po =

2.0,

t, =

l200"

F,

CIRCULAR NOZZLE REF. 6

CIRCULAR NOZZLE REF. 5

"""_

-"

0

.4

.8

1.2

1.6.0.4.0

DISTANCE FROM

CENTER

OF GROUND

PLANE/EQUIVALENT

CIRCULAR

NOZZLE DIAMETER,

R/D,

Figure 24 - Radial variation of local dynamic pressure over ground plane

for various investigations

7 5



I I - N O Z Z L E 2.5 O U TFR O U N DF F E C T I

-

N O Z Z L E 2.1 O U T O FR O U N DF F E C T

a

4

v

W

V

z

I 0.

-

-

4

8

16 12 8

4 0

4 8 12 16

INCHES

111 - N O Z Z L E 2.5 INR O U N DF F E C TV - N O Z Z L E 2.1 INR O U N DF F E C T

V A L U E O F C p S H O W N A R E A C T U A L V A L U E S

X

100

(a)

STATICPRESSUREDISTRIBUTION ON TH E LCWERFUSELAGESURFACE, cp

Ptn /Po =

2.0

ttn

= 1200

O

F

162 8

4

0

4

8 12 16

INCHES

Ill

-

N O Z Z L E 2.5 INR O U N DF F E C TV

-

N O Z Z L E 2.1 INR O U N DF F E C T

(b)

TEMPERATURE DISTRIBUTIONADJACENT TOTHE LOWER FUSELAGE SURFACE, F

Figure 25 - Static pressure and temperature distributions on lower surface

of non-ventilated fuselage for various nozzle configurations

76



-

.003

-

.002

- .001

0

1 -

1

3 4 5 6 7

DISTANCE FROM CENTER OF GROUND PLANE/EQUIV ALENT CIRCULAR NOZZLE DIAME TER, RID,

0

n

I

Ln

n

-

- - ON-VENTILATED FUSELAGE

a

u - VENTILATED FUSELAGE

IN GROUND EFF EC T (Z/D, = 5.0)

I

z

w

-

2 --------

NON-VENTILATEDUSELAGE

LL

LLI

P+

/Po

=

2.0

t" -

LL O U T O F G R O U N DF F EC T

n

VENTILATED FUSELAGE

t - 7 0 ° F

- ,003

- 002

-

.001

0

0 1 2 3 4 5 6 7

DISTANCE FROM CENTER OF GROUND PLANE /EQUIVA LENT CIRCULA R NOZZLE DIAME TER, R/D,

( 0 )

C IR C U L ARNOZZLE 1 .1

Figure 26 - Radial distribution

of

pressures induced on the lower

surface of the fuselage by the jet

77



-

.012

-

.008

-

.004

0

- T

LAJOR

X I S

I 1

0 1 2 3 4

5 6

7

DISTANCE FROM

CENTER OF

GROUND

PLANE/EQUIVALENT

CIRC ULAR NOZZLE OIAME TER, R/D,

a

I

y1


VENTILATED FUSELAGE

a

IN GROUND EF FE CT (Z/D,

5.0)

-

V

E

z ON-VENTILATEDUSELAGE

+

u

VENTILATEDUSELAGE

O U T O F G R O U N D E F F E C T

L L

U

W

V

W

- .020

,016

-

,012

-

,008

-

.004

0

I

I

. i

0

1

2

3

NOR AXIS

i

.

. -

I

4

-

-

DISTANCE FROM CENTER OF GROUND PLANE/EQ UIVALENT CIRCU LAR NOZZL E DIAMETER , R/D,

(b) SUPPRESSOR NOZZLE 2.1

Figure 26

-

Continued

78



- .012

-

.008

-

.004

0

0

1

2 3 4 5 6 7

DISTANCE FROM CENTE R OF GROUND PLANE/EQUIVALENT CIRCULAR NOZZLE DIAMETER, R/De

0

n

I

NON-VENTILATEDUSELAGE

a

-

VENTILATEDFUSELAGE

I

IN GROUND E FFECT Z /De = 5.0)

V"

I-

z

ON-VENTILATEDFUSELAGE

w

u

VENTILATED FUSELAGE

O UT O F G R W N D E F F E C T

-

.020

1 - I

MINOR 1

3 4 5 6 7

DISTANCE FROM CENTER OF GROUND PLAN E/EQU IVALEN T CIRC ULAR NOZZ LE DIAME TER, R/D,

c ) SUPPRESSOR NOZZLE

2.5

Figure 26 - Concluded

79



1 o

.8

.6

.4

.2

0

0

5050 25 30

EXIT WALL ANGLE,

19,

DEGREES

1

o

.8

.6

.4

.2

0

2/D,

0 0

0 1

$ 2

e13

0 4

0 6

D 8

x 10

P

15

Q

20

Q

Z

0 2 4 6

8 10

12

n

ASPECT RATIO, 4

Ptn/Po

=

2.0

ttn = 70" F

1 .o

.8

.6

.4

.2

0

0

1

2

3 4 5 6

SPACING RATIO, S A

(a) NOZ ZLE DISCHARGE TEMPERATURE = 70" F

Figure 2 7 - Dynamic pres sure degradati on versus

exit

wall angle, aspect

ratio, and spacing ratio for all basic suppressor nozzles out

of ground effect

8



1

.o

.8

.6

.4

.2

0

0 5 10 15 2 0 25 30

EXITA L LNGLE,

,

DEGREES

0 2 4 6 8 10 12

ASPECTRATIO, 4

I

. .

Ptn/Po = 2.0

tt,

=

1200" F

0

1 3 4 5 6

SPACING RA TIO, S/W

(b) NOZ Z LE D ISCHARGE T EMPERAT URE

=

1200"

F

Z/D,

0

1

2

3

4

6

8

10

15

20

Figure 27

-

Concluded

81



1 .o

.8

.6

.4

.2

0

0 5 10 15 20 25 30

EXIT WALL ANGLE,

p,

DEGREES

1 .o

.8

.6

.4

.2

0

0 2 4 6 a 10 12

Z/D,

0 0

0 1

0 2

0 4

0 3

ASPECT RATIO, +R

P," 'Po

= 2.0

t

-

1200°F

+"

-

1

.o

.8

.6

.4

.2

0

0 1 2 3 4

5

6

SPACING RATIO, S N

NOZ ZLE DISCHARGE TEMPERATURE = 1200" F

Figure

28

- Differential temperature degradation versus exit wall

angle,

aspect ratio, and sp acing ratio for all basic suppressor

nozzles out of ground effect

82





0 2

1

o

.8

.6

.4

.?

0

'E I

1

.

4

...

6 8

10

1 2 14 16

AX IAL DISTANCE FROM NOZZLEEXIT /EQUIVALENTCIRCULARNOZZLEDIAMETER, Z/D,

.2

.4

,

I . -

Z 'DL

0 1 -

0 3

0 4

D 5

D 6

0 8

x

10

.

17 15

:2.5

7.5 '

Q

20

.6

.8

1 .o 1 . 2 1.4 1.6.8 2.0

TRANSVERSE MIXING DISTANCE RATI0S.X X,50r

=rno.x

( b ) CIRCULARNOZZLE

1 . 1

- DIFFERENTIALTEMPERATURERATIO

Figure 29 -

Continued

84



5 -

4 -

3 -

GEOMETRY

OF

M I X I N G Z O N E

BOUNDARY

OF

"APPARENT CORE"

-

X =

TRANSVERSE M IX IN G

-

DISTANCE FROM BOUNDARY

OF

"APPARENT CORE" AL ONG

X AXIS.

-

Y

=

ANALOGOUS TRANSVERSE

-

M I X I N G DI ST A NC E A L O N G

Y

AXIS.

-

0

1

.o

.8

.6

.4

.2

2

4

6

R

10

12

14

16

18

A X I A LDIST ANCEF ROMNOZ Z LEEXIT /EQUIVALENTCIRCULARNOZ Z LEDIAMET ER,

Z/D,

I 1 1

- LA IN SYMBOLS = VALUES OF x 1 X . 2 5

D 6

D

-

F L A G

S YM BO LS ( / ) = V A L U E S O F Y/Y.

L

.8

1

.o

1.2 1.4.6 1.8 2

.o

TRANSVERSEMIXINGISTANCEATIOS,/X.25, 8. Y l y . 2 5 q z m a x

'max

( c ) NOZZLE 2.1 - DYNAMICPRESSURERATIO

Figure 29 -

Continued

85



~

L

0 .2 .4

.6

.a 1 o

1.2 1.4

1.6 1 .a 2.0

" . . . 3

TRANSVERSE MIXING ISTANCE ATIOS,X/X,gfir 8 Y/Y.50rmOX

mox

(d) N O Z Z L E

2.1

- DIFFERENTIAL T EMPER AT U R ERATIO

Figure

29 -

Continued

86



GEOMETRY OF M I X I N G Z O N E

/ "APPARENI

CORE

B O U N D A R Y

OF

B O U N D A R Y OF

"APPARENT CORE"

X = TRANSVERSE M I XI NG

DISTANCE FROM B O U N D A R Y

Y = ANALOGOUS TRANSVERSE

0 2 4 6

8

IO 12 14 16 18 20

AXI AL DISTANCE FROM N O Z Z L EEXIT / EQUIVALENTCIRCULARNOZZLEDIAMETER, Z

' D ~

.a

.6

.4

.2

0

0

.2

.4

.6 .8 1 .o 1.2 I 4 1 6 1.8 2 .0

TRANSVERSE MIXINGISTANCEAT10S,X/X~~5q,mox

g m o x

( e )

N O Z Z L E 2.5 - DYNAMIC PRESSURE RATIO

Figure

29 -

C o n t i n u e d

87



\

W

Z

J

W

@L

I

Z

V

W

-

I

CL:

LI

W

N

J

N

z

W

u

Z

6

E

I-

n

AXIA L DISTANCE FROM NOZZL E EXIT /EQUIVALENT CIRCULAR NOZZLE DIAMETER, Z/C,

1

0 .2

.4

.6 .8 1 o 1.2 1.4 1.6 1.8 2.0

TRANSVERSE MIXING DISTANCE

RATIOS,

X h . 5 0 ~ a Y / y . 5 0 ~

'max ' m a x

( f ) N O Z Z L E 2.5

-

D I F F E R E N T I A L T E M PE R A TU R E R AT I O

Figure 29

-

Concluded

88



1

o

.8

.6

.4

.2

0

0 .2 .4 .6 . 8 1 .o

DIF F ERENT IAL T E M P E R A T U R ERAT IO, T r m a x T n

(a) DYNAMICPRESSURE

R A T I O

VERSUS DIFFERENTIALT E M P E R A T U R ER A T I O

N O Z Z L E

7 2.1

0

0

2.2

2.3

X

2.4

0

2.5

2.6

2.7

n

2.8

II

2.9

0 1.1

0

0 1.2

1.3

Ptn/Po = 2.0

tt,

=

1200” F

2 4 6 8 10

12

14 16 18 20

A X I A L

D I S T A N C E

F ROM NOZ Z LE EXIT /EPUIVAL ENT C IRCULA R NOZ Z LE D IAMET ER. Z/’D,

(b)

VARIAT ION WIT H D IST ANCE F ROM NOZ Z LE EXIT

Figure 30 - Comp arison of d ynam ic pres sure degr adati on with differential

temperature degradation for all basi c nozzles out of ground effect

89



N O Z Z L E

CONFIGURATION

-

1 .o

.a

.6

.4

.2

0

0

2

4 6

8 10

12

14

16

18

20

AXIAL DISTANCE FROM

N O Z Z L E

EXIT/EQUIVALENT CIRCULAR NOZZ LE DIAMETER, VD,

Figure 31

-

Jet wake degradation characteristics of supp ressor nozzl es

relative

to

the degradation characteristics of a circular

nozzle

for

all

basic nozzles out of ground effect

90



1 .o

.8

.6

.4

.2

0

.%

1

.o

.8

.6

.4

.88 .90 .92 .94 .96 .98 1 .oo

NOZZLEONFIGURATION

& S'W f

7

2.1 5 3.0

0"

0

2.2

5

3.0

5"

0

2.3

5

1.5

15"

x

2.4

5

2.0

15"

2.5

5

3.0

15"

0

2.6

5

4.0

15"

2 . 7

5 3.0

30"

A

2.8

3 3.0 15"

b

2.9 10

3.0

15"

0 1 . 1

CIRCULAR

0

1.2

D E L T A 5 & ,

0 1.3

TWELVE SEGMENT

Pt,/Po =

2.0

tt"

=

1200'F

Z/D,

= 5.0

.86 .88 .90 .92 .94 .9698 1 .oo

EFFECTIVE VELOCITY COEFF ICIENT, Cve

Figure 32 - Jet wake degradation versus thrust of basic nozzles

for free jet tests

9 1



1

.@

.8

.6

.4

.2

@

1

o

1.2.4.6.8

1I

_i

2 . 0

tt

1

.2

2.4.6 2.8

NO ZZL E PRESSURE RATIO,

Ptn/Po

CIRC ULAR NOZ ZLE 1.1, OUT OFGROUND EFFECT

SUPPRESSOR NO ZZ LE 2.1, OUT OF GROUND EFF EC T

SUPPRESSOR NOZZLE

2.5,

OUT OF GROUND EFFECT

-

@

C I R C U L A RNOZ ZLE 1.1, IN GROUND EFF ECT (Z/D, z5.0)

0'

SUPPRESSOR NO ZZ LE 2.1, IN GROUND EFFE CT

(Z/D, = 5.0)

SUPPRESSOR NOZZLE 2.5, N GROUND EFF ECT (Z/D, =5.0)

0 2

4

IO

124 168

20

AXIAL DISTANCE FROM NOZZLEEXIT /EPUIVALENTCIRCULARNOZZLEDIAMETER, z/D,

Figure 33 -

Comparison of thru st and dynam ic press ure degr adatio n of

nozzles

1.1,

2.1, and 2.5 with non-ventilated fuselage

in

and out of ground effect

92



.04

.03

.02

.01

0

O U T O F G R O U N D E F F E C T

1.4 1.6 1.8.0

N O Z Z L E

1 .1

2.2.4 2.6

IN GROUND EF FE CT (Z/D, = 5.0)

1 .o 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6

NOZZLE PRESSURE RATIO, P,,/P~

Figure

34

- Effect of fuselage ventilat ion on effective velocity coefficien ts


93



.... .." ~

e

0

0)

L?

I-

W

I-

z

n

w

u

L L

_I

W

>

W

U

U

W


1

o

1.2

I .4

1.6.8

2.0

2.2 2.4 2.6

N O Z Z L E

1.1 t, = 70" F

n

-

- -

- -

- -

-

-

-

2.1

2.5

2.6

2.8

"-"

Z/D,

=

5.0

VEN T IL AT ED F U SEL AG E

LL

1

o

1.2 .4 1.6 1.8 2.0 2.2

2.4

2.6

NOZZLE PRESSURE RATIO, pt,/po

Figure

35

- Effect of ground proxi mity on effective velocity coefficients

of various nozzle and fuselage configurations

94



I I

-

SUPPRESSOR NO ZZL E

2.1 8.2.5

C IR C U L AROZZLE

1.1

I

(NON-VENTILATED)NON-VENTILATED)

I l l

- IV -

SUPPRESSOR NOZZLE 2.1 8 2.5 CIRCULAR OZZLE 1.1

(VENTILATED)

1 00

40

Q

I

U

I

Z

w

a

NOZZL E NO.

n

I-

U

a

U

Z

u

I- 2 0

a

w

II Ill IV

QUADRANT

Pt,/Po =

2.0

t,, = 70" F

3

1 .1 2.1

c

A

9 3

2 -

.'

2.5

O U T O F G R O U N D EF F EC T

1 .1

49

2.1 2.5

IN GROUND EFFECT (Z/D, = 5.0)

Figure

36

- Relative distribution of thrust losses for various nozzle

and fuselage configurations

9 5



NOZZLEOZZLEONFIGURATIONUSELAGEONFIGURATION

A

SAV

P

-

c 2.1

5 3

0 N O N - VEN T IL AT ED

2.1

5

3

(P V E N T I L A T E D

5

3 15" N O N - VEN T IL AT ED

2.5 5

3

15'

V E N T I L A T E D

2.6 5

4

1

5"

N O N - VEN T IL AT ED

2.6 4 15" V E N T I L A T E D

n

2.8 3 3

15


2.8

3 3

15" V E N T I L A T E D

1.1

CIRCULAR


;

2.5

;

g

J 3 1.1 C IR C U L AREN T IL AT ED

CIRCULAR NOZZLE AND CIRCULAR PLENUM WITH CIRCULAR PLATE

- .

C IR C U L AR N O Z Z L EN D R EC T AN G U L ARL EN U MW IT H C IR C U L ARL AT E

-

OUR CIRCULAR NOZZLES WITH DEL TA MODEL

. . .

. . .

. . . .

.

.

.

EIGHTIRCULAROZZLES WITH DE LTA MODEL ALLA T A

-

-

-

- -

-

FOUR RECTANGULAROZZLESWITHECTANGULARMODEL FROM REF. 2

-

--

-

---- - F O U R R E C T A N G U L A R N O Z Z L E S W I T H D E L T A M O D E L

.06

.04

.02

0

(a) OUT OF GROUND EFFEC T

PROJECTED FUSELAGE AREA/NOZZLE EXIT AREA, Af/A,

b)

IN GROUND EFFECT (Z/D, = 5.0)

0

Figure 37 -

Thrust losses attr ibuted

to

the fuselage for various fuselage

and nozzle configurations

in

and out

of

ground effect

96



+-

w

U

U

W

U

>

U

W

-I

>

.16

k

.I2

W

.08

k

x

U

W

LL

W

Q

z

I

.04

v o

BASIC NOZZLE LOSSES

ADDIT IONA L LOSSES DUE TO FUSELAGE

a DDITIONAL LOSSES DUE

TO

GROUND PROXIMITY (Z/D, =

5.0)

. .

.

:.......

.

.. ..

.

.

.

. ..

.

.

.

_..

. ..

.

.....

. . .

.

.

.

L?

A

P

P

1

. I

2.1 2.5

2.6

Pt"/P0

= 2.0

ttn = 70"

F

k .

P

2.8

N O Z Z L EN U MBER

Documents

CFD Exhaust jet wake and thrust characteristics of several nozzles designed for vtol downwash supresion nasa report.pdf