WindWind Tunnel Tunnel TestsTests Wind o Turbulent ... · WindWind Tunnel Tunnel TestsTests f TblAi f il Wind o Turbulent Airfoils for AC1for AC1 & AC2& AC2 Aircraft Jerzy Żółtak

Aerodynamic DepartmentInstitute of Aviation

WindWind TunnelTunnel TestsTestsff T b lT b l Ai f ilAi f il

WindWind TunnelTunnel TestsTestsff T b lT b l Ai f ilAi f ilof of TurbulentTurbulent AirfoilAirfoilss

for AC1for AC1 & AC2& AC2 AircraftAircraftof of TurbulentTurbulent AirfoilAirfoilss

for AC1for AC1 & AC2& AC2 AircraftAircraftfor AC1for AC1 & AC2& AC2 AircraftAircraftfor AC1for AC1 & AC2& AC2 AircraftAircraft

Jerzy Żółtak

Aerodynamic design of Small Aircraft, Training Workshop, Prague, 18-19 March 2009

Head of CFD Group, Institute of Aviation


Wind Wind Tunnel

TestsTunnel

TestsTestsof ILL518

Testsof ILL518of ILL518

Turbulent Airfoil withof ILL518

Turbulent Airfoil withFlap for AC1 AircraftFlap for AC1 Aircraft



WTT of ILL518 Turbulent Airfoil for AC1 (1)

The tested models h

The test of the ILL518 airfoil were carried out in the IoA T3 low-speed wind tunnel with open test section of 5 m diameter.

The tested models has achord 1 m and a span 1.73 m.The model is equipped inendplates of 1.8 m diameter.

The model of ILL518 airfoil section with flap in T3 Ø5m wind tunnel test section

pThe model was equippedwith pressure tap of diameterof 0.5 mm. The amount ofmeasurement points on a basic model was 59, and on a model with a flap – 52 on the main part of the airfoilon the main part of the airfoiland 29 on the flap.

The wake rake used for CD determination is consistent of 83 total pressure tubes and 4 static pressure tubes for measurements in wake The wake rake istubes and 4 static pressure tubes for measurements in wake. The wake rake is located at 0.75 of chord model trailing edge.For measurements of a pressure distribution on the airfoil and in a wake a four-module switch valve SCANIVALVE 48 DGM equipped with strain gauge


four module switch valve SCANIVALVE 48 DGM equipped with strain gauge pressure sensors DRUCK PDCR22 was used.



Test Programme: The first stage of research was the measurement of aerodynamic characteristics

of the basic airfoil – without a flap - ILL518. The research was carried out for six Reynolds numbers Re = 1, 1.4, 1.6, 2.65, 2.78, 3 106.

The second stage of research was The second stage of research wasthe measurement of aerodynamiccharacteristics of the ILL51 airfoilwith deflected flap, with and

Geometry of the ILL518 airfoil(without flap) tested in IoA wind tunnel

without the simulated contaminationof the leading edge of the airfoil.These tests were made for Reynolds

number Re = 2 65 106number Re = 2.65 106

for angles of the flapdeflection of k = 040°.

Proposed flap


Proposed flap kinematics of a ILL518 airfoil

Aerodynamic DepartmentInstitute of Aviation Aerodynamic Characteristics: Effect of Reynolds Number


CDCL

Cruise Configuration

ΔC = 0 005ΔCD = 0.005

ΔCL=0.2CL

Cm ΔCm = 0.04

ΔCL = 0.2

m

Δα=4° ΔCL=0.2


CLα [°]L


WTT of ILL518 Turbulent Airfoil for AC1 (4) Aerodynamic Characteristics: Effect of Reynolds Number

ΔCL = 0.1Cruise

ConfigurationL g

CLmax

CDminCDmin

ΔCD = 0 001Kmax = (L/D)max

ΔCD 0.001

Kmax= 10


Aerodynamic DepartmentInstitute of Aviation Aerodynamic Characteristics: Effect of Flap Deflection


For tested angles of flap deflection, in addition to the condition of CLmax, increase, the balance of drag in a range of

l d l f C d lcommonly used values of CL, and alsoincrease of pitching moment has been analyzed.

Re=2.65106

CL

L/D

ΔCL = 0.4

L/D

ΔL/D = 20High Lift Configuration

CLL

ΔCLmax

CLmax

δ [°]ΔCL = 0.4

ΔCL = 0.4


α [°] δf [°]δf [°]


WTT of ILL518 Turbulent Airfoil for AC1 (6) Aerodynamic Characteristics: Effect of Flap Deflection

Taking into account results of the analysis for takeoff configuration the angle of flap deflection δk = 15° and for landing configuration deflection δk = 35° were down selected.

tion

CL CDon

figur

a

ΔCL = 0.4

ΔCD = 0.01

ΔC = 1

ndin

g C

o

CL

C

ΔCL= 1

Re= 2.65 106

f and

Lan

Δα=6°

Cm ΔCL= 1

Take

off Δα 6

ΔCm= 0.1


CLα [°]


WTT of ILL518 Turbulent Airfoil for AC1 (7) Aerodynamic Characteristics: Effect of Roughness

Carborundum strip location and size

High Lift Configuration

CL The carborundum powder on strips was used to simulate the

ΔCL = 0.4

leading edge effect contamination by an icing or/and insects.

Carborundum strip on the surface of the airfoil model

ΔC = 0 1Cm

CD

ΔCm = 0.1mΔCD = 0.01

Δ 8°Δ 8°Δα=8°


α [°] α [°]α [°]

Δα=8°Δα=8° Δα=8°

Aerodynamic DepartmentInstitute of Aviation Comparison of experimental and the numerically

di t d di t ib ti f i f il ith t d ith fl


predicted pressure distributions for airfoil without and with flap



di t d ti h t i ti f i f il ith fl


predicted section characteristics for airfoil with flap

ΔCD = 0.01

ΔCL = 0.4ΔCL = 0.4 Δα=6°

Δα=6° ΔC 0 1

Δα=6°

Δα 6 ΔCm = 0.1



Wind T l

Wind T lTunnel

TestsTunnel

TestsTests of ILM115 Turbulent

Tests of ILM115 Turbulent

Airfoil for AC2 AircraftAirfoil for AC2 Aircraft



WTT of ILM115 Turbulent Airfoil for AC2 (1) .

The wind tunnel test was performed in the trisonicperformed in the trisonic wind tunnel N-3

The test was aimed to evaluate the section characteristics CL(α), CD(α) and

Cm(α) of the ILM-115 airfoil over wide the Mach number range M=0.3-0.82

The drag divergence and buffet onset boundaries were determined based on


the test results


WTT of ILM115 Turbulent Airfoil for AC2 (2) .

The 2D ILM-115 airfoil model of 200 mm chord equipped with 69 pressure orifices(d=0.5mm) was used to measure the lift and pitching moment coefficients

A wake rake mounted at the model midspan and located one chord behind modeltrailing edge was used to measure the drag coefficient.The wake was equippedwith 111 total-pressure tubes and 3 static-pressure tubes

Buffet onset was detected by the first divergence from constant part of the modelroot bending moment measured by using strain gauges bridge against the angleof attack

Th t t d t d ith f d fi d t iti f b d l i


The test was conducted with free and fixed transition of boundary layer usingcarborund grains


WTT of ILM115 Turbulent Airfoil for AC2 (3) Aerodynamic Characteristics

Re nolds N mber 2 989 Macha Number: 0.716

Run Number: 67.08PERFORATED WALLSILM115_AC2/T_CESAR

CL = design minα = -0.40o

Priority 1: cruise M = 0.716, Re = 2.95106

CL

cm = -0.0778 cd = 0.0062 cl = 0.214 alpha = -0.40 [deg.]

Nominal Angle of Attack: 0.000Reynolds Number: 2.989Run Number: 67.08

Cp*

-2.0

-1.5

-1.0

upper surface

lower surface

0.4

0.6

0.8

1.0

α 0.40

ΔCL = 0.1ΔCD = 0.002ΔCm = 0.1

Δα = 1

CLCDCm

sing

Dat

e: 1

8-04

-08/

8-Se

p-20

08

-0.5

0.0

0.5

Cp

-0 8

-0.6

-0.4

-0.2

0.0

0.2

m

Tset

/Pos

tpro

cess

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.01.0

x

-1.0

-0.8

Nominal Angle of Attack: 1 000Reynolds Number: 3.007 Macha Number: 0.715


-2.0

CL = design max

α = 0.42o

cm = -0.0737 cd = 0.0066 cl = 0.331 alpha = 0.42 [deg.]

Nominal Angle of Attack: 1.000

Cp*

-1.5

-1.0

-0.5Cp

upper surface

lower surface

0.4

0.6

0.8

1.0

oces

sing

Dat

e: 1

8-04

-08/

8-Se

p-20

08

0.5

0.0

0.5

1 0

C

-0.8

-0.6

-0.4

-0.2

0.0

0.2

Cm requirement


Tset

/Pos

tpro

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.01.0

x

-1.0



CL = design min


Lα = 1.32o

ΔCL = 0.1ΔCD = 0.002ΔC 0 1

CLΔCm = 0.1 CDCm

Reynolds Number: 2.657 Macha Number: 0.610


-3 0

CL = design maxα = 3.01o

Δα = 2

cm = -0.0577 cd = 0.0096 cl = 0.633 alpha = 3.01 [deg.]


Cp*

3.0

-2.5

-2.0

-1.5

p

upper surface

lower surface

0.4

0.6

0.8

1.0

essi

ng D

ate:

18-

04-0

8/8-

Sep-

2008

-1.0

-0.5

0.0

0.5

Cp

-0.8

-0.6

-0.4

-0.2

0.0

0.2

Cm requirement


Tset

/Pos

tpro

ce

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.01.0

x

-1.0



Macha Number: 0 693PERFORATED WALLSILM115_AC2/T_CESAR

CL = design min0 39o


cm = -0.0757 cd = 0.0064 cl = 0.213 alpha = -0.39 [deg.]

Nominal Angle of Attack: 0.000Reynolds Number: 2.923

Macha Number: 0.693Run Number: 66.08

Cp*

-2.0

-1.5

-1.0

upper surface

lower surface

0.6

0.8

1.0

α = 0.39o

ΔCL = 0.1ΔCD = 0.002ΔC 0 1

Δα = 1

CLCDCm

g D

ate:

18-

04-0

8/8-

Sep-

2008

-0.5

0.0

0.5

Cp

-0.6

-0.4

-0.2

0.0

0.2

0.4ΔCm = 0.1

Reynolds Number: 2.940 Macha Number: 0.694


-2 0

Tset

/Pos

tpro

cess

ing

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.01.0

x

-1.0

-0.8

CL = design maxα = 0.44o

cm = -0.0726 cd = 0.0069 cl = 0.328 alpha = 0.44 [deg.]


Cp*

2.0

-1.5

-1.0

p

upper surface

lower surface

0.4

0.6

0.8

1.0

essi

ng D

ate:

18-

04-0

8/8-

Sep-

2008

-0.5

0.0

0.5C

p

-0.8

-0.6

-0.4

-0.2

0.0

0.2

Cm requirement


Tset

/Pos

tpro

ce

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.01.0

x

-1.0


WTT of ILM115 Turbulent Airfoil for AC2 (6) Shadowgraphs: flow visualization

CL design min) CLmax design expectedCL design max

1 6Pr

iorit

y M

= 0

.71

2Pr

iorit

y 2

M =

0.6

1P

3 4Pr

iorit

y 3

M =

0.6

94


P M


WTT of ILM115 Turbulent Airfoil for AC2 (7) Aerodynamic characteristics: effect of Mach Number

CLmax

ΔCL=0.5

Lmax

Δα=0.1

α(CL=0)α(CL=0)

dCL/dα

CDmin

Cm(CL=0)



WTT of ILM115 Turbulent Airfoil for AC2 (8) Aerodynamic characteristics: effect of Mach Number

Comparison of the experimental andC experimental and calculated (H code) drag divergence boundaries

ΔC = 0 1

CL

MDD(CL) with design liftcoefficient range andcomparison of the

ΔCL = 0.1

experimental buffetonset boundary MBO (CL) with required maximumwith required maximum lift coefficients CLmax

including a buffetingi f 0 5 f thΔM = 0 1 margin of 0.5g for the

ILM-115 airfoil atRe~4*106M

ΔM = 0.1



WTT of ILM115 Turbulent Airfoil for AC2 (9) Aerodynamic Characteristics: Low Mach Number (M=0.3)

CL _(CD) M=0.3 Re= 1.35e6CL CD M 0 3 061 f t llΔα=1

CL

CLmax for M = 0.3 (lower Mach number available in N-3 trisonic tunnel)

CL_CD_M=0.3_run061_ free trans_s walls

ΔCL=0.1Δα=1

CD ΔCD=0.01 ΔCL=0.2

0 5 0 3 0 1 0 1 0 3 0 5 0 7 0 9 1 1 1 3 1 5

Cm

CL

Cm _(CL) M=0.3 Re=1.35e6Cm_CL_M=0.3 run061_free trans_s walls

CmΔCL=0.2

ΔC =0 05

M = 0.3, Re = 1.35106,

free transition, solid walls

CL_Alpha_M=0.3_Re=01.35e6CL_alpha_M=0.3_run61_solid walls_free trans

ΔCm 0.05

α[°] CL

Influence of a lam/tur transition: M= 0.3÷0.8, perforated walls, the carborundum powder on strips


the carborundum powder on stripsMain effect: the loss in CLmax due about 6% for M = 0.3, Re = 1.35106


di t d ti h t i ti f i f il ith fl

WTT of ILM115 Turbulent Airfoil for AC2 (10)

predicted section characteristics for airfoil with flap

Validation of numerical results

airfoil: ILM 115

Ma = 0.61

Re = 2.66*106


Documents

WindWind Tunnel Tunnel TestsTests Wind o Turbulent ... · WindWind Tunnel Tunnel TestsTests f TblAi f il Wind o Turbulent Airfoils for AC1for AC1 & AC2& AC2 Aircraft Jerzy Żółtak