Drag Reduction of MAV by Biplane Effect Chinnapat THIPYOPAS Graduate student, Department of...
-
Upload
greyson-kellar -
Category
Documents
-
view
219 -
download
3
Transcript of Drag Reduction of MAV by Biplane Effect Chinnapat THIPYOPAS Graduate student, Department of...
Drag Reduction of MAV by Biplane Effect
Chinnapat THIPYOPASGraduate student, Department of Aerodynamics
and
Jean-Marc MOSCHETTA Associate Professor of Aerodynamics, Department of
Aerodynamics
Ecole Nationale Supérieure de l’Aéronautique et de l’Espace (SUPAERO)
10 Av. Ed. Belin, Toulouse, France
P1/29
Contents
• Introduction• Part 1 Optimization - (Experimental)
- (Numerical)
• Part 2 Biplane Combinations • Part 3 Propeller Influence• Conclusions
Department of Aerodynamics SUPAERO P2/29
Contents
• Introduction• Part 1 Optimization - (Experimental)
- (Numerical)
• Part 2 Biplane Combinations • Part 3 Propeller Influence• Conclusions
Department of Aerodynamics SUPAERO P3/29
Monoplane MAV concepts
Minus-Kiool57g - 20.6 cm
Plaster64g - 23 cm
Department of Aerodynamics SUPAERO P4/29
Monoplane-MAVs
Total Drag = Parasite Drag + Induced drag
100 % 20-30 % 70-80 %
Plaster, SUPAERO
Drenalyne, SUPAERO Biplane
Concept !!
Maxi-Kiool, SUPAERO
Induced Drag 76%*
* J.L’HENAFF, SUPAERO 2004
Department of Aerodynamics SUPAERO
P5/29
Monoplane vs. biplane
1 FD iD maxP
2 2/FD iD maxP
2 2FD 2/iD maxP
Constant lift, speed & overall dimension
wing drag = Parasite Drag + Induced Drag
Parasite drag is a function of Skin-Friction which depends on Wing Chord
Induced Drag is very strongly effected by Aspect Ratio
Department of Aerodynamics SUPAERO
P6/29
Contents
• Introduction• Part 1 Optimization - (Experimental)
- (Numerical)
• Part 2 Biplane Combinations • Part 3 Propeller Influence• Conclusions
Department of Aerodynamics SUPAERO P7/29
Design Constraints• Maximum overall dimension : 20 cm• Lift at 10 m/s = Weight = 80 grams• Manoeuvrability :
Cost function
• Minimum Drag at cruise condition
2)(
)(
max
L
cruiseL
C
C
Optimization process
Department of Aerodynamics SUPAERO
20 grams min.
for payload
P8/29
Experimental setup• Wind tunnel
– Test Section 45cm x 45cm – Velocity 10 m/s
• Measurement– 3-component balance
• Models– 16 flat-plate wing models
• Aspect ratio 1 – 4• Taper ratio 0.2 – 1.0• Sweep angle 0 - 50°
• Reference surface/length– For comparison, every model
is referenced by same area, length
Strut
AR1, Taper 1, No Swept
20cm.AR2.5, Taper0.6, Swept25°
Department of Aerodynamics SUPAERO P9/29
Model’s Drag Correction
Model
Strut
Strut
Model is not attached to strut
mod el total strutDrag Drag Drag
Department of Aerodynamics SUPAERO P10/29
Results
LC minDCminDC maxLC KAC Monoplane
AoADC DL /
Biplane
DC DL / AoA
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
No.
A4S50T1
A4S50T0.6
A4S50T0.2
A4S25T0.6
A4S0T1
A4S0T0.2
A2,5S50T1
A2,5S25T1
A2,5S25T0.6
A2,5S0T1
A2,5S0T0.6
A1S50T1
A1S50T0.2
A1S25T0.6
A1S0T1
A1S0T0.2
Disc
Model Name
15.13.5080.091---5.3110.27810.4240.03680.01413.598376.7
14.93.5330.091---5.950.30560.4420.02390.00953.488379.5
14.33.4990.092---5.2210.29430.4810.02950.01243.392684.1
7.65.6130.058---3.2610.23630.4180.02750.01334.946896.6
9.834.3860.074---1.4970.24550.3810.03450.01674.553994.1
8.465.4040.060---2.4530.24130.3550.03260.01664.327399.3
11.54.5520.071---5.7660.3190.5350.01310.00673.0513102.9
6.55.2270.061---4.5030.26830.6010.0290.024.0961137.9
6.386.386.2886.2880.0520.052---4.9040.30320.6190.02340.01723.6615146.7
7.445.8990.054---2.430.29660.5720.01620.01123.556137.9
6.386.386.0366.0360.0550.055---3.0990.28140.6270.02730.023.7786146.7
12.23.9670.08121.82.5520.2527.6330.37380.9440.02810.01832.4902130.2
11.34.1280.078212.5300.2569.9670.41781.0460.02240.01632.4114144.0
7.565.5320.05813.513.53.9533.9530.1640.1648.9260.38571.6210.010.01122.4667224.8
8.564.390.07314.63.3990.1895.3360.38881.4490.02140.02192.5556200.0
12.33.8030.085232.2090.2936.1760.51270.8870.02020.01462.1647144.0
4.65.8710.0558.568.565.0525.0520.1270.1278.320.35781.9970.01470.02322.8223314.2
(cm.)
***Area
Red color is a value referenced by wing’s area
Department of Aerodynamics SUPAERO
P11/29
Numerical method
• Vortex lattice method : code TORNADO v126b [T. Melin; KTH]
• Drag evaluationParasite Drag = 1.5 of equivalent flat plate skin friction drag (Blasius Eq. + Thwaites formula)
+
Induced drag (TORNADO)
• Various models : – aspect ratio– taper ratio– sweep angle
Department of Aerodynamics SUPAERO P12/29
ResultsThe variation of Lift to Drag ratio
0
1
2
3
4
5
6
7
8
9
10
0 1 2 3 4 5AR
L/D
1 0.80.6 0.4
1 0.80.6 0.41 0.80.6 0.4
1 0.80.6 0.41 0.80.6 1
0.8 0.61 0.80.6 0.6
Monoplane
Triplane
The variation of Cruising angle of attack
0
5
10
15
20
25
30
35
40
0 1 2 3 4 5ARAo
A
S 10.8 0.60.4 10.8 0.60.4 10.8 0.60.4 10.8 0.60.4 10.8 0.61 0.80.6 10.8 0.60.6
An approximate stall angle curve
Biplane
• L/D at cruise cond. increases with AR• Poor manoeuvrability of monoplane wings with AR 2 and higher• greater L/D for biplanes
• L/D of Triplane AR4 is smaller than biplane because of high parasite drag.
• Biplane AR2-3 is suitable for flight
Department of Aerodynamics SUPAERO P13/29
-50
0
50
100
150
200
250
0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 0,4
Drag
Mas
s
Monoplane
Biplane
60 grams
Monoplane
Biplane
Biplane vs. monoplane
Department of Aerodynamics SUPAERO
80
P14/29
Contents
• Introduction• Part 1 Optimization - (Experimental)
- (Numerical)
• Part 2 Biplane Combinations • Part 3 Propeller Influence• Conclusions
Department of Aerodynamics SUPAERO P15/29
Zimmerman
Planform Area (m2) CL (max) CD (min) L/D (max)
Zim1 0.0264 1.251 0.0533 4.03
Zim2 0.0173 0.586 0.0419 5.21
Zim1Inv 0.0264 0.986 0.0538 3.75
Zim2Inv 0.0173 0.605 0.0344 4.96
Plaster1 0.0245 0.909 0.0411 4.92
Plaster2 0.0166 0.605 0.0354 5.47
Drenalyne1 0.0273 1.260 0.0528 4.46
Drenalyne2 0.0173 0.585 0.0375 4.81
-95
-75
-55
-35
-15
5
25
45
65
85
0 20 40 60 80 100 120 140 160 180 200
-100
-80
-60
-40
-20
0
20
40
60
80
100
0 20 40 60 80 100 120 140 160 180 200
Plaster
Other planforms
Drenalyne
-100
-80
-60
-40
-20
0
20
40
60
80
100
0 20 40 60 80 100 120 140
Department of Aerodynamics SUPAERO P16/29
Inverse ZimmermanTorres et al., Univ. Florida, 1999
Plaster wingReyes et al., SUPAERO, 2001
Calculation
Biplane type L/D cruise L/D max. CLmax/CLcruise Cm0
BSWE1 5.16 5.16 1.71 -0.0371BSWE2 5.6 5.83 1.64 -0.0260BSWE3 5.01 5.07 1.54 -0.0042BPLA1 7.03 7.19 2.04 0.0418BPLA2 7.89 8.63 2.02 0.0198BPLA3 6.67 6.76 1.79 -0.0107BZIM1 6.85 7.07 2.32 0.0603BZIM2 7.66 7.95 2.06 -0.0347BZIM3 6.28 6.44 1.87 -0.0165
Department of Aerodynamics SUPAERO P17/29
Scale 1(SUPAERO)
Parameters• Gap• Stagger• Decalage angle
Side View
U
Lower Wing
Gap
Stagger Upper Wing
Decalage angle
End-plates
Scale 3(S4, ENSICA)
Department of Aerodynamics SUPAERO P18/29
GapInfluent of Gap (Bi-Zim)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
-10 0 10 20 30
AoA
CL
CL Gap3
CL Gap5
CL Gap7
Pitching moment coefficient curve for stagger constant (S0)
-1.5
-1
-0.5
0
0.5
1
-20 -10 0 10 20 30 40
AoA
Cm CMaT1 G0.75 S0
CMaT1 G1.0 S0
CMaT1 G1.25 S0
CMaT1 Mono wo winglet
Lift to drag ratio for stagger constant (S0)
-10
-8
-6
-4
-2
0
2
4
6
8
-20 -10 0 10 20 30 40
AoA
L/D
Finesse G0.75 S0
Finesse G1.0 S0
Finesse G1.25 S0
Finesse Mono wo winglet
• Reduced an influence between both wings
• Increase lift slope and maximum lift
• Not change position of aerodynamics center
• Increase drag from the structure L/D not change
Department of Aerodynamics SUPAERO
P19/29
StaggerInfluent of Stagger and tandem
(Bi-Zim Gap5)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-10 0 10 20 30
AoA
CL
Cz Tandem2Cz Tandem1CL S2CL S4CL S6CL Gap5 S0
Influent of Stagger and tandem (Bi-Zim Gap5)
-4
-2
0
2
4
6
8
-10 0 10 20 30
AoA
L/D
L/D Tandem2 L/D Tandem1
L/D S2 L/D S4
L/D S6 L/D Gap5 S0
The effect of stagger to pitching moment
-1.5
-1
-0.5
0
0.5
1
1.5
-20 -10 0 10 20 30
AoA
Cm CMaT1 G0.75 S+30
CMaT1 GO.75 S+15CMaT1 G0.75 S0CMaT1 G0.75 S-15
• Increase lift slope and maximum lift
• Aerodynamics center is between two wing
• No stagger has more L/D
• Local AoA of fore-wing is bigger
Department of Aerodynamics SUPAERO P20/29
Decalage Angle
Decalage angle influence
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
-15 -5 5 15 25
AoA
CL
CL D+9 CL D+7CL D+3 CL D+0CL D-3 CL D-5CL D-7
Decalage angle influence
-4
-2
0
2
4
6
8
-15 -5 5 15 25
AoA
L/D
L/D D+9 L/D D+7L/D D+3 L/D D+0L/D D-3 L/D D-5L/D D-7
Done with positive stagger model
• Strongly effect to stall angle and L/D
• Negative decalage give highest wing performance
Department of Aerodynamics SUPAERO P21/29
Visualisation
S4, ENSICA
Department of Aerodynamics SUPAERO P22/29
Contents
• Introduction• Part 1 Optimization - (Experimental)
- (Numerical)
• Part 2 Biplane Combinations • Part 3 Propeller Influence• Conclusions
Department of Aerodynamics SUPAERO P23/29
Propeller Effect (S4)
Motor & propeller
Test section
Power supplyMoveable system
TubeTest section
Upper Wing
Lower Wing
U Motor
Side View
7 4 6 5
1 2 3
Front View
Half Span
Center line
Upper wing
Lower Wing
• 7 motor positions
were observed.
Inf luent of motor to lif t coeff icient
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
10 15 20 25 30AoA
CL
CL no motor
CL motor
Upper wing stalls
• At pre-stall regime, lift is increased due to propeller.
Lift increases
Lower wing stall at 22°
Lower wing not stalled
• The stall angle is delayed, lower wing is still not stall at AoA 22°
• Lift, maximum lift and L/D are increased.
Department of Aerodynamics SUPAERO P24/29
Propeller Effect (Scale 1)
• Zim2 wing planform scale 1 (20cm. Max dim.)
• Motor in front of wing gives highest performance.
• The motor countering / encountering wingtip vortex effects are very small.
Monoplane Wing
P25/29
Propeller Effect
-2
-1
0
1
2
3
4
5
6
7
-10 -5 0 10 20 25
Incidence
B = mid position
R = upper wingG = lower wing
L/D
155
• Motor on upper and lower wing have the same effect
• Middle position is poorest
Moter's influent
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-10 0 10 20 30
AoA
CL
Cz bz1
Cz bz2m
Cx bz2mh1
Cx bz3m
Cx bz3mh1
• Attached on upper and lower wing
• Same efficiency• Delay stall
phenomena, increase maximum lift
Attach Motor to the model
Motor sting
Model struts
Effect of induced flow to model
P26/29
Contents
• Introduction• Part 1 Optimization - (Experimental)
- (Numerical)
• Part 2 Biplane Combinations • Part 3 Propeller Influence• Conclusions
Department of Aerodynamics SUPAERO P27/29
Conclusions• Biplane is better than monoplane for this design criteria
• Wind tunnel measurements and numerical calculations confirm the interest for biplane MAV wings.
• AR 2.5 to 3 are appropriate for biplane MAV concepts.
On-going developments
• More accuracy measurement
• Further optimization of motor position (wingtip)
• Optimizing biplane-connecting structure
• Pototype of Biplane MAV
Department of Aerodynamics SUPAERO
P28/29
Thank you for your attention
P29/29
Drag Reduction of MAV by Biplane Effect
Chinnapat THIPYOPASGraduate student, Department of Aerodynamics
and
Jean-Marc MOSCHETTA Associate Professor of Aerodynamics, Department of
Aerodynamics
Ecole Nationale Supérieure de l’Aéronautique et de l’Espace (SUPAERO)
10 Av. Ed. Belin, Toulouse, France
Parasite and Induced Drag
Drag of drag biplane and monoplane
02040
6080
100120
140160
0 20 40 60 80 100% Do
Do (monoplane) Di (monoplane) Dt (monoplane)Do (biplane) Di (biplane) Dt (biplane)
The zone which biplane has total drag less than monoplane configuration
(when Induced drag > 45% total drag)
55
Department of Aerodynamics SUPAERO
Parasite and Induced Drag
Drag of drag biplane and monoplane
02040
6080
100120
140160
0 20 40 60 80 100% Do
Do (monoplane) Di (monoplane) Dt (monoplane)Do (biplane) Di (biplane) Dt (biplane)
case a.)AR1
b.)AR2
c.) 2 x AR2
total
Surface S S/2 S/2
Lift for each wing W W W/2
Max. Lift L L/2 L/2 L
Lift coef. CL 2CL CL
Skin friction drag Df Df/1.414 Df/1.414 1.414Df
Induced drag coef. CDi 2CDi CDi/2
Induced drag Di Di Di/4 Di/2
Total drag 1.5Df + Di 1.5Df /1.414 + Di 1.5*1.414Df + Di/2
Airplane drag = Parasite Drag + Induced Drag
Parasite drag is a function of Skin-Friction which depends on Wing Chord
Induced Drag is very strongly effected by Aspect Ratio
The zone which biplane has total drag less than monoplane configuration
(when Induced drag > 45% total drag)
55
Results
• Reynolds number effect on L/D
• Winglet can improve wing performance
• Gap increases the lift slope and maximum lift
• L/D increased by positive stagger
• Stall angle and maximum lift changed by decalage angle
• Parasite drag from the strut between two wing is very important
Lift to drag ratio, influent of velocity and winglet
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
-20 -10 0 10 20 30 40
AoA
L/D
Finesse Mono w o w inglet
Finesse V. 5
Finesse V. 15
Finesse w inglet
Lift coefficient curve for stagger constant (S0)
-1.5
-1
-0.5
0
0.5
1
1.5
2
-20 -10 0 10 20 30 40
AoA
CL
CZa G0.75 S0
CZa G1.0 S0
CZa G1.25 S0
CZa Mono wo winglet
The effect of stagger to lift to drag ratio
-10
-8
-6
-4
-2
0
2
4
6
8
10
-20 -10 0 10 20 30
AoAL
/D
Finesse G0.75 S+30Finesse GO.75 S+15Finesse G0.75 S0Finesse G0.75 S-15
Lift coefficient
-1.5
-1
-0.5
0
0.5
1
1.5
2
-20 -10 0 10 20 30
AoA
CL
CZa S0 D-6°CZa G1.0 S0CZa S0 D+6°
Propeller-induced lift
Increasing in lift
Why are these 16 models ?
• The Taguchi method was used in the first experimental design table. But an interaction between each parameters is very strong.
• To determine the optimizing model, some interpolation was formed to complete the experimental table.
Gap effectLift coefficient curve for stagger constant
(S0)
-1.5
-1
-0.5
0
0.5
1
1.5
2
-20 -10 0 10 20 30 40
AoA
CL
CZa G0.75 S0
CZa G1.0 S0
CZa G1.25 S0
CZa Mono wo winglet
Lift - drag coefficient curve for stagger constant (S0)
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.2 0.4 0.6 0.8
CD
CL
CXa G0.75 S0
CXa G1.0 S0
CXa G1.25 S0
CXa Mono wo winglet
Pitching moment coefficient curve for stagger constant (S0)
-1.5
-1
-0.5
0
0.5
1
-20 -10 0 10 20 30 40
AoA
Cm CMaT1 G0.75 S0
CMaT1 G1.0 S0
CMaT1 G1.25 S0
CMaT1 Mono wo winglet
Lift to drag ratio for stagger constant (S0)
-10
-8
-6
-4
-2
0
2
4
6
8
-20 -10 0 10 20 30 40
AoA
L/D
Finesse G0.75 S0
Finesse G1.0 S0
Finesse G1.25 S0
Finesse Mono wo winglet
Stagger effectThe effect of stagger to lift coefficient
-1.5
-1
-0.5
0
0.5
1
1.5
2
-20 -10 0 10 20 30
AoA
CL
CZa G0.75 S+30
CZa GO.75 S+15CZa G0.75 S0
CZa G0.75 S-15
The effect of stagger to drag coefficient
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.2 0.4 0.6 0.8
CD
CL
CXa G0.75 S+30CXa GO.75 S+15CXa G0.75 S0CXa G0.75 S-15
The effect of stagger to pitching moment
-1.5
-1
-0.5
0
0.5
1
1.5
-20 -10 0 10 20 30
AoA
Cm CMaT1 G0.75 S+30
CMaT1 GO.75 S+15CMaT1 G0.75 S0CMaT1 G0.75 S-15
The effect of stagger to lift to drag ratio
-10
-8
-6
-4
-2
0
2
4
6
8
10
-20 -10 0 10 20 30
AoA
L/D
Finesse G0.75 S+30Finesse GO.75 S+15Finesse G0.75 S0Finesse G0.75 S-15
Decalage effectLift coefficient
-1.5
-1
-0.5
0
0.5
1
1.5
2
-20 -10 0 10 20 30
AoA
CL
CZa S0 D-6°CZa G1.0 S0CZa S0 D+6°
Poar curve
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.2 0.4 0.6 0.8 1
CD
CL
CXa S0 D-6°CXa G1.0 S0CXa S0 D+6°
Pitching moment coefficient
-1.5
-1
-0.5
0
0.5
1
1.5
-20 -10 0 10 20 30
AoA
Cm
CMaT1 S0 D-6°CMaT1 G1.0 S0CMaT1 S0 D+6°
Lift to drag ratio
-8
-6
-4
-2
0
2
4
6
8
-20 -10 0 10 20 30
AoA
L/D
Finesse S0 D-6°
Finesse G1.0 S0
Finesse S0 D+6°
Scale 1
• Sweptm Plaster and Inv-Zim planeform
• Connected with strut• Biplane
– parameters• Gap• Stagger• Decalage angle
Swept PlanformInfluent of stagger
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
-10 -5 0 5 10 15 20
AoA
CL Cz G5S0
Cz G5S2
Cz G5S4
Cz G5S6
Influent of stagger
-4
-2
0
2
4
6
8
-10 -5 0 5 10 15 20
AoA
L/D
L/D G5S0 L/D G5S2
L/D G5S4 L/D G5S6
Decalage angle influence
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
-15 -5 5 15 25
AoA
CL
CL D+9 CL D+7CL D+3 CL D+0CL D-3 CL D-5CL D-7
Decalage angle influence
-4
-2
0
2
4
6
8
-15 -5 5 15 25
AoA
L/D
L/D D+9 L/D D+7L/D D+3 L/D D+0L/D D-3 L/D D-5L/D D-7
Inverse-ZimmermanInfluent of Gap (Bi-Zim)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
-10 0 10 20 30
AoA
CL
CL Gap3
CL Gap5
CL Gap7
Influent of Stagger and tandem (Bi-Zim Gap5)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-10 0 10 20 30
AoA
CL
Cz Tandem2Cz Tandem1CL S2CL S4CL S6CL Gap5 S0
Influent of Stagger and tandem (Bi-Zim Gap5)
-4
-2
0
2
4
6
8
-10 0 10 20 30
AoA
L/D
L/D Tandem2 L/D Tandem1
L/D S2 L/D S4
L/D S6 L/D Gap5 S0
Influent of Stagger and tandem (Bi-Zim Gap5)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 0.2 0.4 0.6 0.8CD
CL
Cz Tandem2
Cz Tandem1
Cx S2
CL S4
CL S6
CL Gap5 S0
Visualisation
Tuft method
Smoke generation
Motor-Propeller Effect
• Attached on upper and lower wing• Same efficiency• Delay stall phenomena, increase
maximum lift
Moter's influent
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
-10 0 10 20 30
AoA
CL
Cz bz1
Cz bz2m
Cx bz2mh1
Cx bz3m
Cx bz3mh1
Motor's influent
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
CD
CL
Cz bz1
Cz bz2m
Cx bz2mh1
Cx bz3m
Cx bz3mh1
GEOBAT