110. Putnam - an Analytical Study of the Effects of Jets Located More Than One Diameter Above a Wing at Subsonic Speeds

7/28/2019 110. Putnam - an Analytical Study of the Effects of Jets Located More Than One Diameter Above a Wing at Subso

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AD-A280 151

NASA TECHNICAL NASA TM X-71965M EM ORANDUM COPY NO .

Cnr-IAN ANALYTICAL STUDY OF THE EFFECTS OF JETSLOCATED MORE THAN ONE JE T DIAMETER ABOVE A

WING AT SUBSONIC SPEEDSBy LAWRENCE E. UTNAM PT T.

MAY 1974 iW.9

S ' --- 94-15960

This Informal documentation medium is used to provide accelerated orspecial release of technical information to selected users. The contentsmay not meet NASA formal editing and publication standards, may be re-vised, or may be Incorporated in another publication.

NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONLANGLEY RESEARCH CENTER, HAMPTON, VIRGINIA 23665

94 5 26 12 6 DTIC QUA-LM .. "D


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1. 06'.I . siemmmdaeinhn N& ~ 3. Redpileat' Cale" 011M14 z- 71965 7

4. Thf and Subof &. eport IDIsAn Analytical Study of the Effects of Jets May 1974Located More Than One Jet Diameter Above A 6. r-.rmin Ormwentios odeWing at Subsonic Speeds

7. Autor(s) e. u ,formlinrnization Report No.Lawrence E. Putnam 10. Work Unit No.

*9. Palrforming Orgniatio Name and Addren 0ss-6o. te,.,q ~w.. 01-24-06-01.NASA Langley Research Center 11 . Conwect or Grant No.Hampton, VA 23665

13. Type of Report and Period Covered12. Sponsoring Ageancy Namew and Address TcnclMmrnu,2. .m.v s.eTechnical MeimorandumNational Aeronautics and Space Administration 14 . S.o.eing Aency CodeWashington, DC 20546I&. upplementary Note

Interim Technical Information Release, subject to possiblerevision and/or later formal publication

16. Ablmc

A procedure has been developed to calculate the effects of blowingtwo jets over a swept tapered wing at low subsonic speeds. The algorithmused is based on a vortex lattice representation of the wing liftingsurface and a line sink-source distribution to simulate the effects of theje t exhaust on the wing lift and drag. The method is limited to thosecases where the je t exhaust does not intersect oy wash the wing. Thepredictions of this relatively simple procedure are in remarkably goodagreement with experimentally measured interference lift and interferenceinduced drag.

17. Kv words (Suggeted by Author(s)) (STAR category underlined) I&. olributon StatemeunAerodynamics

Interference Lift Upper-Surface Blowing Unclassified - UnlimitedInterference Drag Swept WingsJet Effects Tapered WingsSubsonic Flow119. Securty Ckmif. lof this reort 20. Saourty Clooif. (of Ok ae t. o fP~ 22. ,Unclassified Unclassified 4g8

The National Technical Information Service, Springfeld. Virginia 22151*Avalabte rom I(STIFR4ASA Scintificand Technical Information Facility, P.O. Box 33. College Perk, MD 20740


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AN ANALYTICAL STUDY OF THE EFFECTS OF JETSLOCATED MORE THAN ONE JET DIAMETER ABOVE

A WING AT SUBSONIC SPEEDS

By Lawrence E. PutnamLangley Research Center

SUMMAR Y

A procedure has been developed to calculate the effects of blowingtwo jets over a swept tapered wing at low subsonic speeds. The algorithmused is based on a vortex lattice representation of the wing lifting surfaceand a line sink-source distribution to simulate the effects of the je texhaust on the wing lift and drag. The method is limited to those caseswhere the Jet exhaust does no t intersect or wash the wing. The predictionsof this relatively simple procedure are in remarkably good agreement withexperisentally ueasured interference lift and interference induced drag.

The results of the analytical study have indicated that substantialincreases in wing lift and reductions in wing induced drag can occurwhen jets are blown over a wing. The magnitude of these effects increasewith increasing ratio of je t exit velocity to free-stream velocity. Theresults also indicate that the interference effects are the most favorablewhen the nozzle exits are located ahead of or at the wing leading edge andinboard near the wing center line. The present method does no t correctlypredict the effects of jet vertical location at heights less thanapproximately 1.5 jet exit diameters; however, as the jet vertical locationIs reduced to this height the favorable effects of blowing jets over awing increase.


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INTRODUCTION

Recently, there has been renewed interest in locating the propulsionsystems of future je t transport airplanes forward and above the wing. Thisunconventional engine location can take two forms. In one form, the jet isexhausted tangential to the wing upper surface to take advantage of Coandaturning of the jet exhaust as it passes over the wing to achieve high lift(refs. 1 through 4). In the second form the jet exhaust is raised so thatthe exhaust flow does no t attach to the wing to avoid the cruise dragpenalties associated with the first form. In both cases the jet noisepropagated downward during takeoff and landing may be reduced by the shield-ing effects of the wing (refs. 5 and 6). In addition to noise shieldingbenefits, locating the propulsion system forward may also alleviate massbalance problems associated with advanced supersonic transport airplaneconcepts and may improve the wing flutter characteristics of such airplanes.To date, however, except fo r references 7 through 9, there is very littleinformation available fo r use in assessing the effects of over wing je tblowing on subsonic or supersonic cruise performance and on climb performanceof future jet transport airplanes.

The purpose of the present study was, therefore, to investigate analy-tically the effects of blowing jets over wings on subsonic cruise and climbperformance. An elementary analytical procedure based on the vortex latticetheory fo r the wing and the theory of reference 10 fo r a jet exhausting intoa subsonic stream has been developed to calculate the effects of blowing oneor two jets over a swept tapered wing. As a result of the basic assumptions,the method is limited to the second case where the jet exhaust does not inter-sect or wash the wing. As long as the jet is sufficiently high such that itdoes not violate the above condition the effects of je t to free-streamvelocity ratio (i.e. jet thrust coefficient), location of the jet exhaustrelative to the wing, nozzle exit diameter, wing leading edge sweep, wingaspect ratio, and wing taper ratio on the lift and drag induced by blowingjets over a wing at subsonic speeds can be analytically investigated.

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SYMBOLS

Ae exit area per nozzle

AR wing aspect ratio, bSref

b wing span

CA axial force coefficient

CDi induced drag coefficient

ACD,i (CD,i) je t on - (CD,i) je t off

CDo drag coefficient at zero lift

CL lift coefficient . 85o- WorTIC.LiAB

ACL (CL) je t on - (CL) je t off asu a eedaton 0

ci normal force coefficient

" ~ ~ Vi IIi idiDist ci

3I


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c wing chord or chord of elemental vortex lattice panel

c section lift coefficient1

d nozzle exit diametere

XIslope of line source or line sink distribution

Ic length of chordwise vortex-line segment on wing

Icore length of core of je t exhaust plume

MI Mach number of je t at nozzle exite

MW free stream Mach number

N number of points or number of elemental vortex latticepanels

total pressure of jet at nozzle exit

pa free stream static pressure

Q strength of line source or sink distribution


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qe dynamic pressure of je t at nozzle exit

free strewn dynamic pressure

Sref reference area (wing planform area)

s semi-width of horseshoe vortex

U velocity of jet at nozzle exit

U free stream velocity

ui circulation induced perturbation-velocityui' 1' ccscponents in positive X-, Y-, and Z- directions

uje1 , vjet, V je t induced perturbation-velocity components' Jt in positive X-, Y-, and Z- directions

Ve effective velocity ratio W______,pU2

V radial velocity in je t axis system induced byr line sink-source distribution

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x, Y, Z orthogonal right-handed primary Cartesiancoordinate system with origin at wing apex(see figure 1). Positive X-direction isforward, positive Y-direction is towardright wing tip, and positive Z-direction isdownward. X- Y plane parallel to wing chordplane

I Rj Jet cylinderical coordinate system with originat nozzle exit (figure 3); positive X-directionis in direction of Jet exhanst

x, r cylinderical coordinates associated with Jet

"Xc/4 longitudinal location in primary Cartesiancoordinate system of midspan of quarter-chordof elemental panel"longitudinal location in primary Cartesian

x3o/h coordinate system of midspan of three-quarter-chord of elemental panel

xe* Ye , ze primary Cartesian coordinates of nozzle exit

x primary Cartesian X-coordinate of wing leadingle edge at ye

yp primary Cartesian Y-coordinate of controlpoint on elemental panel

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angle of attack, deg

r circulation strength

Ye ratio of specific heats of je t at nozzle exit

Y. ratio of specific heats of free stream

duimy variable of integration

n fraction of wing semispan from wing root chord inY-direction

ne location of je t axis in fraction of wing semispan,2 yeb

e camber angle of wing at control point, deg

A sweep angle, deg

Ac/4 wing quarter chord sweep angle, deg

A wing leading edge sweep angle7e


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taper ratio, c tc r

Pe density of Je t at nozzle exit

pW free stream density

Subscripts

av average

c chordwise

r root

8 spanwise

t tiptotal total

METHOD OF ANALYSIS

The algorithm used in the present study to calculate the effects ofblowing exhaust jets over a swept tapered wing is based on a vortex latticerepresentation of the wing lifting surface and a line source-sink distri-bution to represent the effects of the exhaust Jets. The method, which hasbeen programmed for a digital computer, assumes that the flow external tothe Jet exhaust is steady, irrotational, inviscid, and incompressible. It

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was also assumed that th e je t is not deflected by the free stream, the jetsdoes not intersect or wash the wing, and the je t cross sectional shape isnot distorted by the wing flow field or by any crossflow components of th efree stream velocity. A typical wing planform and engine arrangementfo r which the effects of blowing jets over the wing can be calculatedwith th e present method is shown on figure 1.

The vortex lattice method used to represent th e wing liftingsurface is based on references 13 and 12. Each half of th e wing issubdivided in both th e spanwise and chordwise directions into 50 orless elemental areas. In the present computer program th e number ofspanwise and number of chordwise panels is arbitiary; however, unlessotherwise specified, all calculations for the present study were madewith 5 equal spaced chordwise and 10 equal spaced spanwise divisionson each half of the wing. Each elemental area is represented by ahorseshoe vortex with the bound portion lying along the localquarter-chord-line of the element. (See figure 2.) The trailingvortices lie streamwise along the inboard and outboard edges of eachpanel on the wing chord plane. Aft of the wing trailing edge, th etrailing vortices continue in the chordwise direction, that is, itis assumed that the trailing vortices are not turned by the wingdownwash or by th e free stream velocity. Note that this is not th e

conventional method of locating the trailing vortices parallel toth e free stream velocity as used in reference 12, bu t is similar toth e formulation of reference 11. The boundary condition that th eflow be tangential to the wing surface is satisfied fo r each elementat a point on th e lateral mid-point of the local three-quarter-chordline of th e element.

The induced effects of th e je t exhaust were simulated with adistribution of line sinks and sources located on the longitudinalaxis of the jet. The axis of the je t was divided into a number ofsegments over which the sink or source strength was assumed to belinear. This continuous line sink-source distribution is equivalent

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to a series of triangular elemental distributions as illustrated infigure 3. The radial velocity induced by the jet at a point in th esurrounding flow field is therefore given by the following equation:

x2KIr (X2 - C) dCVr(x'r) = 4n f [(X-C) 2+ r 2 J 3/2

N-1 Xl+I

+K Ir (XI -x ) (xj~4)dC21+1- I I[(X-02

+ r2132

+ C X 1 )dC + KNr (C- N)d

x [(Xi-0 + r21 3/2 'N- + r21 3/2

The strength of each elemental line source or sink was adjusted togive the inflow velocity on the boundary of th e Jet predicted by th emethod of reference 10. In the present analysis only thoseinterference effects resulting from the je t radial perturbationvelocities are considered: any perturbation velocities inducedparallel to the jet axis are neglected. In effect, therefore, th einterference effects of the je t on the wing are attributed to anupwash distribution along th e wing lifting surface.


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To determine the circulation strength of each elemental horseshoevortex on the wing, the following equation for the circulationinduced downwash velocity must be satisfied at each control point on thewing:

._i = sin (a+ e) - jt - ujetUcos e u u

A sketch illustrating this boundary condition at each control point isshown on figure 4. It is apparent from this sketch how the induced effectsof the je t modify the boundary condition equation. Note that in thepresent formulation the uje t perturbation velocity only arises when th eaxis of the jet is not parallel to the wing chord plane.

After the circulation strengths fo r the horseshoe vortices aredetermined, th e forces acting on the wing can be determined. Fromreference 11, the forces acting on each spanwise segment of vortex filamentin coefficient form are:

CN,s = U, +U j oi refJ

For each chordwise segment of vortex filament the force coefficients are:

A,c

11

l2 ul 2sI I


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C C2rc v, v~t -Nc U: 1 U. U I

Where r is the net circulation strength resulting from th eCindividual circulations of each trailing horseshoe vertex leg formingthat segment. The total normal force and axial force acting on th ewing are obtained by sumwing the normal and axial forces acting on allsegments. The lift and induced drag coefficients are then obtained from:

CL = CN,total Cos o - CA,total sin a

CDi = CA,total cos a + CNtotaI sina

This solution fo r the induced drag is equivalent to th e near fieldsolution of reference 12. The integration of th e wing span loaddistribution (the fa r field method) to obtain the induced drag is notapplicable to the present problem. Because of the induced upwash fieldgenerated by th e Jet exhaust th e assumption inherent in th e fa r fieldmethod are violated. (See refs. 13 and 14.)

DISCUSSIONComparison of Present Method with Other Theoretical Methods and

with Experiment

To verify th e vortex lattice algorithm used to represent the wingin th e present method, th e computed lift and drag characteristics of anaspect ratio 8 straight wing without a Jet have been compared to th epredictions of reference 12. (See fig. 5.) The present computer

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algorithm gives essentially th e same results as reference 12 fo r eachof th e cases considered: a flat wing, a wing with Clark Y camberdistribution, and a twisted wing with no camber. There are some smalldiscrepancies in the results of the two methods at th e higher angles ofattack. This small discrepancy is associated with the nonlinearizationof the boundary conditions in the present method. Note that th e nearfield induced drag results of reference 12 are compared with th epresent method.

Experimental investigations of the effects of blowing jets over awing are very scarce; in particular for the case where the je t issufficiently high such that it does not wash the wing. One source ofsuch data is reference 15. The comparison of the present method withthese experimental results shown on figure 6 indicates very goodagreement at vertical locations of the je t exhaust greater than 1.5nozzle exit diameters above the wing. In general, the effects of je t tofree-stream velocity ratio, longitudinal location of the jet, and verticaldistance of the je t above the wing on the interference lift are wellpredicted. As :he je t approaches the wing, however, the experimentalresults show a significant increase in interference lift over th epredicted values. This discrepancy results when the je t washes the wingand Coanda turning of the je t with its associated increase ininterference lift occurs. This effect of Coanda turning of the je texhaust is of course neglected in the present method.

A comparison of the present method with th e experimental data ofreference 9 fo r two jets blowing over a 500 swept leading edge wingwith an aspect ratio of 3 and a taper ratio of 0.3 is shown on figure 7.These experimental data were obtained at nozzle exit total pressure tofree-stream static pressure ratios from approximately 1 to 6 and at free-stream Mach numbers of 0.4, 0.6, and 0.7. The theory of reference 10 wasderived fo r an incompressible jet exhausting into an incompressibleexternal stream with no density difference between the two streams. The

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variable density case can be related to the incompressible constantdensity solution of reference 10 with an effective velocity ratio (ref. 16)as defined in th e following equation

V = = = [+(Ye- 1) (Ye-1)

r e e e e Pt,e

For an air je t with ye = ya , 1.4

M I +0.21?e Me VPte/p---

As shmon on figure 7 (a) and 7 (b) the effective velocity ratiosatisfactorily correlates the interference lift and the interferenceinduced drag resulting from blowing two jets over the 500 swept leadingedge wing of reference 9 at Mach numbers from 0.4 to 0.7. The predictionsof the present method are in good agreement with the experimental results.These results indicate that the present method can be extended to thecase where the je t and free stream are compressible and at differentdensities by use of th e effective velocity ratio concept. An illustrationof the application of the present method using the effective velocityratio concept to the prediction of the effects on lift and induced dragdue to blowing jets over a wing is shown on figure 7 (c) fo r the 500 sweptwing of reference 9. The following equations were used to obtain th epredicted lift and induced drag when the jets were blowing over the wing:

S. .. . ' l I I I III I IIII4


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CL,predicted = (CLJet off)measured " "CLpredicted at a given a

CD,i)predicted CD,i)jet off)measured + (ACD,dipredicted at a given CL

The predicted lift and drag characteristics using the present method tocalculate the effects of the jets with the above equations are in goodagreement with the experimental results. Of particular interest is theexperimentally indicated improvement in induced drag (not necessarilyin total drag) due to blowing two jets over the wing and the similarpredictions of the present method.

Effect of Vortex Lattice Arrangement

Shown on figure 8 is the effect of the number of elemental chordwisepanels on the predicted lift and induced drag of an aspect ratio 8,taper ratio 0.3 wing having the quarter chord swept 00 with and withouttwo jets blowing over the wing. It is apparent that there is essentiallyno effect of varying the number of elemental panels on the predictedlift and induced drag of the wing or on the increments in lift and dragdue to je t blowing. Varying the number of spanwise elemental panelsdoes result in a change in the predicted lift and induced drag for thewing with and without je t blowing. (See fig. 9.) It appears, however,that the interference effect due to je t blowing is not a strong functionof the number of elemental vortex lattice panels. Therefore, regardlessof the vortex lattice arrangement used, the predicted effects of je tblowing are essentially uneffected. Therefore 5 chordwise and 10 spanviseelemental panels have been used for all calculations of the present paper.

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4.I/ / / // H / I Ii- -- --- _ __ s- , -

Effect of Velocity Ratio

The predicted effects of effective velocity ratio on theinterference lift and interference induced drag due to Je t blowingare shown on figures 6, T, and 10 for an aspect ratio 2 straight wing,an aspect ratio 3, taper ratio 0.3 wing with 500 swept leading edge,and an aspect ratio 8, taper ratio 0.3 wing with 300 swept quarterchord, respectively. The present method predicts an increase in inter-ference lift coefficient with increasing Je t blowing (that is,increasing i/Ve). This favorable interference effect is essentiallyuneffected by angle of attack. The present method also predicts adecrease in induced drag with increasing ratio of jet velocity tofree-stream velocity 1/V . This favorable increment in interferenceinduced drag increases with lift coefficient. On figure 10 (b) areshown typical calculations of the effects of effective velocity ratioon wing span load distribution and on section lift coefficient.Increased Je t blowing results in an increased distortion of the spanload distribution. Note that this increased distortion does not implyincreased induced drag since integration of the span load distributionto obtain induced drag is only valid for planar wings without externalinterference effects. As would be expected the span load does increasein the vicinity of the jet. Increasing Je t blowing also increasesthe section lift coefficient over the entire wing span.

Effect of Jet Location

The predicted effects of Je t location on the interferencelift and interference induced drag due to two Jets blowing overvarious wing configurations are shown on figures 6 and 11 through 14.Increasing the vertical distance of the Jets above the wing (figs. 6and 11) causes a decrease in the interference lift and a reductionin the favorable interference induced drag. Moving the nozzle exitahead of the wing leading edge causes a small increase in16


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interference lift and a small increase in th e favorable induced dragincrement. (See fig. 12.) Moving the nozzle exit aft of th e wingleading edge causes a decrease in the interference lift and asubstantial reduction in th e favorable induced drag increment. Thecalculations shown on figures 13 and 14 indicate that the closer th ejets are located to the wing center line the more favorable th einterference effects due to blowing two jets over a wing. This isindeed a fortuitous result since reference 4 indicates that fo r atwo engine configuration th e engine should be located inboard tominimize th e engine-out effect on rolling moment associated with uppersurface blowing configurations during takeoff and landing.

CONCLUDING REMARKS

A procedure has been developed to calculate the effects ofblowing two jets over a swept tapered wing at low subsonic speeds.The algorithm used is based on a vortex latt ice representationof the wing lifting surface and a line sink-source distributionto simulate the effects of the jet exhaust on the wing lift anddrag. The method is limited to those cases where th e je t exhaustdoes no t intersect or wash the wing. The predictions of thisrelatively simple procedure are in remarkably good agreementwith experimentally measured interference lift and interferenceinduced drag.

The results of the analytical study have indicated thatsubstantial increases in wing lift and reductions in wing induceddrag can occur when jets are blown over a wing. The magnitudeof these effects increase with increasing ratio of jet exitvelocity to free-stream velocity. The results also indicatethat the interference effects are the most favorable when th enozzle exits are located ahead of or at the wing leading edge andinboard near th e wing ceter l ine. The present method does not

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correctly predict the effects of Jet vertical location at heightsless than approximately 1.5 Je t exit diameters; hovever, as theJet vertical location is reduced to this height th e favorableeffects of bloving Jets over a wing increase.

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REFERENCES

1. Riebe, John M.; and Davenport, Edwin E.: Exploratory Wind-TunnelInvestigation to Determine the Life Effects of Blowing Over Flapsfrom Nacefles Mounted Above the Wing. NACA Tech. Note 4298,June 1958.

2. Turner, Thomas R.; Davenport, Edwin E.; and Riebe, John M.:Low-Sptad Investigation of Blowing From Nacelles MountedInboard and on the Upper Surface of an Aspect-Ratio - 7.0350 Swept Wing with Fuselage and Various Tail Arrangements.NASA Memo 5-1-59L, June 1959.

3. Phelps, Arthur E., III: Aerodynamics of the Upper Surface BlownFlap. STOL Technology, NASA SP-320, Oct. 1972 pp 97-110.

4. Phelps, Arthur E., III; and Smith, Charles C. , Jr.: Wind-TunnelInvestigation of an Upper Surface Blow Jet-Flat Powered-LiftConfiguration. NASA TN D-7399, 1973.

5. Anon: Aircraft Engine Noise Reduction. NASA SP-311, 1972.

6. Dorsch, Robert G.; and Reshotko, Meyer: EBF Noise Tests withEngine Under-the-Wing and Over-the-Wing Configurations.STOL Technology, NASA SP-320, Oct. 1972, pp 455-473.

7. Kettle, D. J.; Kurn, A. G.; and Bagley, J. A. : Exploratory Tests onA Forward-Mounted Overwing Engine Installation. C. P. No. 1207,Brit. A.R.C., 1972.

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8. Wimpresa, John K.: Upper Surface Blowing Technology As AppliedTo the YC-l4 Airplane. SAE Paper 730916, Oct. 1973.

9. PUtnam, Lawrence E.: Exploratory Investigation at Mach NumbersFrom 0.40 to 0.95 of the Effects of Jets Blown Over a Wing.NASA TN D-7367, 1973.

10. Squire, H. B.; and Trouncer, J.: Round Jet In A General Stream.Report Aero. 1904, *R.A.E., Jan. 1944.

11. Fox, Charles H., Jr.: Prediction of Lift and Drag fo r Slender Sharp-Edge Delta Wings in Ground Proximity. NASA TN D-4891, 1969.

12. Margason, Richard J.; and Lamar, John Z.: Vortex-Lattice FortranProgram fo r Estimating Subsonic Aerodynamic Characteristics ofComplex Planforms. NASA TN D-61Q2, 1971.

13. Pope, Alan: Basic Wing and Airfoil Theory, First Ed., McGraw-HillBook Co., Inc., 1951, pp 200-203.

14. Cone, Clarence D., Jr.: The Theory of Induced Lift and MinimumInduced Drag of Nonplanar Lifting Systems. NASA TR R-139, 1962.

15. Falk, H.: The Influence of the Jet of a Propulsion Unit on NearbyWings. NACA TM 1104, 1946.

16. Carter, Arthur, W.: Effects of Jet-Exhaust Location on the LongitudinalAerodynamic Characteristics of a Jet V/STOL Model. NASA TN D-5333,1969.

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x

4I

SI I1 1 ecr

z

Figure 1. General layout of a ypical wing planform showing axis system and location of nozzle exits.


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x

b/2

Y~cp

'30/4 Bi4. ound vortex

S-- Control point

Trailing vortices

Plgure 2.- Sketech of a typical elemental vortex-lattice panel on wing.


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Rj

X1 X? X3 x4 xxN

FIre .- Illustration of source-sink distribution used to represent effects of je t exhaust.


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Wing chord plane and plane containinghorseshoe vortices

w.Je t

x "Ujet

z Flow directionat control point(tangent to comberline)

Boundary condition:UcDsin (a+ 9) z (wi + wjet) cos a +ujet sine

Figure 4.- Sketch illustrating boundary conditions at each controlpoint on wing.


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12

-r-

.~. .. .- ...a, deg 4

, .

. ............. 0 Present methodo-- Reference 12 -

.04 i -- r -*

.o,.02h + 't~-J!

.03 if- 1--

-. 2 0 .2 .4 .6 .8 1.0CL

(a) Flat wing.

Figure 5.- Comparison of present method with that of reference 12 for an AR - 8,A - 1.0 straight wing (jet off). (Reference 12 near field solution forinduced drag shown.)


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8S: i . .. . . . .....

--

Z.1 . -4

-4. . . -7". . . - ..,-,1d-i !. _I L '":I ! I t ! [ '

-8-

--t---4- ..-... 0 Present method--------It- .7 -1- -t Reference 12.04- 7-.I

.03 . '' " ,-_ -. ._ ;........ , .. .. ...... ... .. .

CD, -.

;: . - 4- 1 + -t-. 2 0 .2 .4 .6 .8 1.0

GL

(b) Wing with Clark y comber distribution.

Figure 5. - Continued.


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R2

. 0 --::,: 3-. ]] ]]i ; ]]t]] ] . . .' : , ::i! !

-- --i .4 - ::

i. ....... ....

- i. .. 0. .2_; .4 : .6 . .. 10

i-4-ure .

a degt :!, :; : :i # .:L._L_! 7-- . 0 Present method i:'1 .. :: ., -

.04A

4H Ifl: T . I J:i ..

CD, i .02

0-. 2 0.2 .4 .6 .8 1.0CL

(c) Wing with twist distribution.

Figure 5.- Concluded.


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A*.08 ,

.al.0 Experiment M.,


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.06 . . .....4 MOD adog0 0 4l

0 .6}Experimen7.04 .765- Present method

........... 4.

&CL.04

.04

,04

00

*0....

2 3 4 5V/Ve

(a) Interference lift coefficient-Figure 7.- Comparison of present method with experimental data ofreference 9 for two jets blowing over a wing with AR - 3,X 0.3, an d A 50t . AaISrof - 0.0078, (x m - Xte)/de - 2.59,

no 0.46, z,/l - -1.5.

a


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0 : .6 Experiment.004 < .(b) : ter,,r,nc Present methodefient.

Fi re 7.'ntied. :C L

;::Y,

-. 00'!i,,A-DT'- : - :. .. ; f. ' ' . .. -

0L - iij.! h:aL l:::i ::: :. i]ii:iii~rlf tii:!t : : ::

7' . .. 35 _

-.0 .... .- -. .. ......

VVe(b) nterference indu:c'"ra c....ficie'nt.

..,F gur 7... ntinue.d.,.


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4 ii:" i " ' ... ....... ! i ] : ...! .. ..A.:

-4 -

. ---- Jet off Experiment0 0.2824 Experiment- - -.... 2824 Present method

.04

ICt

(c) Effect of Jet blowing on :Lift and drag coefficient at N0, - OJlO.

Figure 7.- Concj~xided.

CD, 1 I02lllI


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7.

1.0 0 e .028,,1 0 Jet off 028 .a, dog:14:.1 Q0. 0

.9 H z oe .024

.020 . .....

.7 .. ' .016S ~ C O ,0, ....... i

3; .... .... 7

... ..... ..

CCL5.00 0Nc 2 4 642

NC Nc

Figure 8. - Effect at number of chordwise elemental vortex lattice panels when Ns 10 on the calculated lift andInduced drag of a wing with AR - 8, .0.3, nd Ad 4 - 00 and with two jets having A lSrer 0.025located at (xe - x,)d -0.0, re 0.3, nd Ze.de - -1.5.

i ll I I I II 4"


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L

. 7.

.4.

.020 T.i+.C .01

CL .S .0082

C ij.4

,3 II"

.4 ".N0 ....

.30.

0 2 4 6 S 10 0 2 4 6 8 10NS NsFigure .- Effd !number mlsspavsemental vortsxlatapanels when N 5 n the calculated lift and

Co. I

and Induced drag ofa ing with AR - 8, A 0.3. and A 4 0 and with tw o jets having A/Srf - 0.125Iociat Nx- milld. -0.0.I0 -0.3.and zjdd -1.5.


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[H -r: T I

il M

--. 7- --- r-- :n..: T_1. -- --...-7 -4--II

0. A

, ~Jet of f0.2.3.03 - .3 -

.02 . VT"4

-. 0.2. .6 .8.

CD, i .01. 0 2 sd*-.1

-. 2 O0. .4 .6 1.0LCL

(a) Effecton CL an CD,,.Figure 10.- Calculated afect of effective velocity ratio of two jet* on aerodynmiccharacterisltics of a win with AA a 8, A m 03,3 and AC/4 ' 30*, A./sef -. 012,Ol

(me - xle)/de - 0.0. , -) 9 .25, %/do -, -1.401.


37/50

V 0CL GO ,.4 Jet off 0.1495 0.0008

- 0.2 .2206 -0.0010.3 .1773 .0003.4 .1611 .0006.6 .1514 .0008

.57

0

14-

iu 1l..:o :.ed

t ... ... . l -e" !:2L7o ........

OE."{

0 .2 .4 .6 .8 1.0(b) Effect on span load distribution andsection llft coefficient at m. 20.

FiguLre .I0.- Continued.


38/50

.08-- - - a, deg

0_L .0447*

""~. - 0 8 "... . . .....

AGD, i -. 004 C

SI 2 3 4 5/ ,/vVeI 1 I i , I1.0 .6 .5 .4 .3 .2

VeWc)Effect on ACL and "D,.

Figure 10.- Concluded.


39/50

12

a~deg __

-4 Jet off- -.....- - -1.401- -- 1.750-2.000

-2.500.03 1T---4- -4-" -A- * H- ........ 1

Io,.0.02 ----4-~

I.-01; 00--

- .01 .. . .-. 2 0 .2 .4 .6 .8 1.0

CL(e) Efect on CL and .D,:.

Figure II.- Calculated effect of vertical location of two jets on aerodynamic characteristicsof an AR - 8, A - 1.0 stralght wing. Ae/Srs. =0.0125, V. - 0.20.e - 0.25,(N* -" *)Id - 0.0.


40/50

: - - - 1 I -... ... .. . ... . . . . . . . .- . . .- _ -

z*/d* CL CD, iJet off 0.1647 0.0011.4 1401 .2310 -0.00071.750 .2264 -0.00052.000 .2235 -0.00042.500 .2182 - 0.0003

t

.7

Fu 1

0..

.,6 - T i

0 :.2. : 4 .6 . 1.(b). Efeto nladdsrbto nseto lif cofiin at a 2.

Fiur-Cninued


41/50

.08

ACL .04 a, deg-

oo..JJ .. il iii0 LCL0.2

0 .

ACD -. 04 -

-. 008-1.2 -1.6 -2.0 -2.4 -2.8

Ze/de

(c) Effect on 'L and 8D,i-Figure 1l.- Concluded.


42/50

12- G~ W-

a, 0og)/d 4

-4 Jet of f1.402

.03-

.01Et ~~lI L WCC

V.2 0.0,n 0.25 .4 . .8 1.001C C L


43/50

(Xe -- Xe)/de 'L GD, iJet off 0.1647 0.00112.803 .2398 -0.0019.4 1.402 .2382 -0.00150 .2315 -0.00081.402 .2166 -0.0003

.9c4, .2

ILC0l

1.2"

CLCGV Ii .. ...

00 .2 .4 .6 .8 1,0

(b) Effect on spun. load distribution andsection 1,Lft coeff icient at a - 20.

Figure 12.- Continued.


44/50

... ....II

ACL .04 -1-. _____,_ 0 .2

"~ ~~~~. ... .. ... . .. :

.0123 2 I 0 -I -2

; (Xe- X~e)/de" / " " (c) Effect on ACL ad ACDt

Figure 12.- Concluded.AG I I I I


45/50

12

a, deg 4

r776

-4 7T . Jet off.50.75

.03 - "00

.027.

-. 0I

D: -0

-. 2 0 2 .4 .6 8 10CL

(a) Effect on CL and CD *Figur. 13.- Calculated affect of lateral locat.on of two jets on aerodynamiccharacteristica of en AR 8, X 1.0 straig.t wing. AIS 0.0125,V. 020 (z .x.)/d0.0, d --1.401


46/50

:i ;A l Tlt',1

iti",I:il :: tg3

~;;.2

e CL CDiJet off 0.1647 0.0011-0.25 .2310 -0.0007

1.6 .50 .2268 -0.0004.75 .2160 .0000---- .00 . 1879 .0007

!; - -'-" --. - , !

1.224 .6 8...0

sec;tion lit c.+ fcit t . 20 ,4 .4 .- .SttO

(b) MLeect on open load distributlon sandsection 31ft, coefficient at -20.


47/50

.08 -"4 ..............

ACL .04a ! deg...0000

CL0 -0.2 .4 I '

mm . ....... ..

ACD,i -. 004

-.008 LL" 7 i0 .2 .4 .6 .8 1.017

(c) Effect O,CL a AnD,iFigure 13.- Concluded.


48/50

17

-. 4 jet of f- - 0.25 -

_ _.50+

.751CDI .0 .1 .00

~~~4i~ -(a)~~~~ffci

L.0L

A118w. 1'.- Calculated effect of lateral location of two jets on aerodynamiccharacteristics of a i irth A S. X-0.3 and A /4"30.A./Srsf - 0.0123, Ve - 0.20. (x~ -zi)/de 0.0, and soldo - -1.401.


49/50

C1 | I|. Jet off 0.1495 0.00060.25 .2206 -0.0010.50 .2019 -0.0005S.75 .1825 -0.0001

1.00 .1605 .0006

i. _0

W.. O2.....

0~ OiItI1.2 -7

on' -6 "-

.4

0 .2 .4 .6 .8 1.0

(b) Eft'ect on evesn ltoad distributi.on an dsection lift,coefficient at u, = 2.

now. - Comtsmd..


50/50

-_-,

.0-

ACL 04o - 0 L i

CL0.2

~%i-.004 :

-. 0080 .2 .4 .6 .8 1.0

(a) Effect on arLnd XDi.

Fiv-re 14.- Concluded.

Documents

110. Putnam - an Analytical Study of the Effects of Jets Located More Than One Diameter Above a Wing at Subsonic Speeds