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Transonic Buffet Control on 3D Turbulent Wings using Fluidic Devices
Part 1: Open loop study
J. Dandois 1, J.-B. Dor 2, P. Molton 3, A. Lepage 4 F. Ternoy 5, V. Brunet 1 and E. Coustols 2
1 Applied Aerodynamics Department 2 Aerodynamics and Energetics Modeling Departement 3 Fundamental and Experimental Aerodynamics Department 4 Aeroelasticity and Structural Dynamics Department 5 Model Design and Manufacturing Department
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Buffet phenomenon
- Buffet limits operational flight conditions of a given aircraft (Mach number, lift), which leads to a margin (30%) between CLcruise and CLbuffet_onset - Buffet control would provide more flexibility in wing design
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Plan
1) S3Ch wind tunnel tests (PRF BUFET’N Co & JTI SFWA WP112) => “research-type” tests to compare the efficiency of passive and
active VGs => acquisition of an extensive database for the validation of numerical
simulations (unsteady pressure transducers, PIV and LDV) => preparation of the S2MA WTT
1) S2MA wind tunnel tests (EC FP6 AVERT & PRF BUFET’N Co ) => final demonstration of the buffet control in an industrial-type wind
tunnel (open loop & closed-loop)
Testing of active devices at the ONERA S3Ch WT Mechanical VGs Fluidic VGs: small nozzle M=2, Φ=1mm (continuous/pulsed)
S3Ch wind tunnel tests
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Flow control by mechanical VGs: α = 3.5°, Mp = 0.815
80% 70% 60% 50% Baseline
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Flow control by fluidic VGs: α = 3.5°, Mp = 0.815
80% 70% 60% 50% - Flow separation suppressed between Y/b = 60 and 80% - Results similar to mechanical VGs
Baseline
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y/b=70%-1.5
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-0.5
0
0.5
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0 10 20 30 40 50 60 70 80 90 100
x/c(%)
-Kp
Baseline
2g/s (Cmu=2.3e-4)
1.8g/s (Cmu=2.1e-4)
1.6g/s (Cmu=1.8e-4)
1.35g/s (Cmu=1.5e-4)
1.2g/s (Cmu=1.4e-4)
1.1g/s (Cmu=1.3e-4)
1g/s (Cmu=4.3e-5)
0.8g/s (Cmu=3.4e-5)
0.7g/s (Cmu=2.2e-5)
0.5g/s (Cmu=1.1e-5)
JTI-SFWA 1.1.2 : S3Ch Wind Tunnel Tests
• Fluidic VGs: mass-flow rate effect
⟨ = 3.5°
- Fluidic VGs are effective for very low values of the mass-flux (2g/s)
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y/b=70%-1.5
-1
-0.5
0
0.5
1
0 10 20 30 40 50 60 70 80 90 100
x/c(%)
-Kp
Baseline
all active 2.4g/s(Cmu=2.8e-4)
1VG/2 active 2.2g/s(Cmu=2.5e-4)
1VG/3 active 2.1g/s(Cmu=2.4e-4)
1VG/4 active 0.9g/s(Cmu=1e-4)
1VG/5 active 0.7g/s(Cmu=8.1e-5)
1VG/6 active 1g/s(Cmu=1.1e-4)
1VG/7 active 0.8g/s(Cmu=9.2e-5)
• Fluidic VGs: spacing effect
⟨ = 3.5°
JTI-SFWA 1.1.2 : S3Ch Wind Tunnel Tests
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• Fluidic VGs: spanwise location effect
⟨ = 3.5° y/b=70%
-1.5
-1
-0.5
0
0.5
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0 10 20 30 40 50 60 70 80 90 100
x/c(%)
-Kp
Baseline
VG 1 to 7 1.3g/s(Cmu=1.5e-4)
VG 8 to 13 0.9g/s(Cmu=1e-4)
VG 14 to 19 1g/s(Cmu=1.1e-4)
VG 20 to 25 1.1g/s(Cmu=1.3e-4)
JTI-SFWA 1.1.2 : S3Ch Wind Tunnel Tests
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Unsteady measurements: comparison of mechanical and fluidic VGs effects
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• Decrease of the RMS level on the pressure and on the accelerometers • Nearly same effect between passive and active VGs
Mechanical VGs => BAY model in elsA
elsA RANS computation of the S3Ch model with passive VGs
M = 0.82, α = 3,5o (buffet for α>3,0o)
ReAMC = 2,8 106
Exp.
Good agreement between CFD results and experimental data if the mesh is fine enough to discretize each vortex
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Exp.
Fluidic VGs => Overset grid method
Good agreement between CFD results and experimental data
elsA RANS computation of the S3Ch model with fluidic VGs
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Peniche / Fuselage / Wing Wing cross-section:
OAT15A airfoil Wing span: 1.225m Chord length:
0.450m 0.225m ϕ=30°
ONERA S2MA WT
S2MA WTT
Devices tested: Baseline Configuration Mechanical VGs Fluidic VGs (continuous flow rate) Fluidic TED (continuous flow rate) designed with PPRIME
ONERA Half-model
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Baseline (α=4.25°) Mechanical VGs (α=3.5°)
Fluidic VGs (α=4.25° - Cµ=0.06%)
S2MA WTT: comparison between passive and fluidic VGs
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- Effect of Fluidic VG at Cµ=4.6 10-5 (3g/s) comparable to Mech. VG - Saturation efficiency on CL for Fluidic VGs at Cµ higher than 9.2 10-5
- BUT still efficient on decreasing unsteadiness (Kulites transducers)
Fluidic VGs configuration
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Fluidic VGs configuration
Lift gain maximum for a spanwise spacing of 46d
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Pulsed Fluidic VGs configuration
- Low pass filter behaviour of the shock oscillation - Frequency bandwidth of the shock around 160Hz
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Fluidic TED at Cμ=0.0027
M=0,82 Pi=0,6b
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0,2
0,4
0,6
0,8
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-2 -1 0 1 2 3 4 5 6 7
Alpha (°)
Cz
Baseline (192)FTED Cmu=0,0090 (472)FTED Cmu=0,0058 (474)FTED Cmu=0,0036 (475)FTED Cmu=0,0027 (477)Baseline (193)
Fluidic TED vs. Baseline Configuration
Mech. TED deflected at 30°
Fluidic TED configuration
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Comparisons at iso-CL
Fluidic TED configuration
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- Mechanical/Fluidic VGs delay buffet onset by 0.3° and 1° respectively - Fluidic TED delay buffet onset only in CL
Results summary
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- Mechanical/Fluidic VGs delay buffet onset both in the (M,α) and (M,CL) planes - Fluidic TED delay buffet onset only in the (M,CL) plane For more details see: “Buffet Characterization and Control for Turbulent Wings”,
Aerospace Lab, Vol. 6, 2013. http://www.aerospacelab-journal.org Next presentation: closed-loop buffet control by A. Lepage
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Results summary