Development of Simplified Boundary Condition of SaOB Actuator Based on High-Fidelity CFD Simulations

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Corey Patterson
5 years ago
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Hospodář, (Výzkumný a zkušební letecký ústav, a.s.) D. Dolgopyat, A.

1 Development of Simplified Boundary Condition of SaOB Actuator Based on High-Fidelity CFD Simulations P. Vrchota, A. Prachař, P. Hospodář, (Výzkumný a zkušební letecký ústav, a.s.) D. Dolgopyat, A. Seifert (Tel Aviv University) Coordinator : Martin Wahlich Airbus WP Leader : Mark Nichols BAe

2 Outline Motivation SaOB actuator Bench-top test Simplified boundary condition Conclusion 5nd 3AF International Conference on Applied Aerodynamics, 017

$Motivation Simplified surface boundary condition \ Reduction of the complexity of the geometry \ Significant reduction of the computational resources \ Simulation of the rows of actuators \$

3 Motivation Simplified surface boundary condition \ Reduction of the complexity of the geometry \ Significant reduction of the computational resources \ Simulation of the rows of actuators \ Consideration of AFC within the design process AFLoNext project \ Technology stream 4 \ Active Flow Control on wing trailing edges * *aflonext.eu 5nd 3AF International Conference on Applied Aerodynamics, 017 3

$SaOB actuator Fluidic device developed at Tel Aviv University \ Combination of an ejector and a bi-stable$ $openings in the aerodynamic surface and an increased flow rate through the actuator \ Oscillation frequency$

4 SaOB actuator Fluidic device developed at Tel Aviv University \ Combination of an ejector and a bi-stable fluidic oscillator \ Ejector creates low pressure in the actuator suction cavity \ suction flow through openings in the aerodynamic surface and an increased flow rate through the actuator \ Oscillation frequency range can be modified by changing the length of the feedback tube 5nd 3AF International Conference on Applied Aerodynamics, 017 4

$Frequency [Hz] Velocity [m/s] SaOB actuator The small actuator creates larger pressure losses than its large counterpart \ Lower blowing velocities \ Higher oscillation frequency Original SaOB Rigth$

5 Frequency [Hz] Velocity [m/s] SaOB actuator The small actuator creates larger pressure losses than its large counterpart \ Lower blowing velocities \ Higher oscillation frequency Original SaOB Rigth port Original SaOB Left port Small SaOB Rigth port Small SaOB Left port supply pressure [psi] supply pressure [psi] Original SaOB Rigth port Original SaOB Left port Small SaOB Rigth port Small SaOB Left port 5nd 3AF International Conference on Applied Aerodynamics, 017 5

$Velocity [m/s] Bench-top Test Set-up MEADOW aerodynamic lab at TAU \ Ambient conditions \ Still air Equipment \ Hot Wire probe used \ 3D traversing system \ Pressure sensors 16 15$

6 Velocity [m/s] Bench-top Test Set-up MEADOW aerodynamic lab at TAU \ Ambient conditions \ Still air Equipment \ Hot Wire probe used \ 3D traversing system \ Pressure sensors Velocity distribution \ at nozzle s exit \ Suction velocity \ Oscillation frequency Y [mm] 5nd 3AF International Conference on Applied Aerodynamics, 017 6

$Simulation of SaOB Bench-top Test Single actuator was simulated \ Experimental$ $airfoil \ Ambient condition \ No cross flow (still air) Boundary condition to$

7 Simulation of SaOB Bench-top Test Single actuator was simulated \ Experimental calibration of SaOB - same procedure used for CFD simulation \ No housing into airfoil \ Ambient condition \ No cross flow (still air) Boundary condition to simulate the behavior of SaOB goal 5nd 3AF International Conference on Applied Aerodynamics, 017 7

8 Simulation of SaOB Bench-top Test CFD code Edge \ Navier-Stokes solver for unstructured grids \ Solves the compressible NS equations \ RANS/RANS-LES/LES solver \ Node-centered/ finite-volume formulation EARSM Hellsten K- \ URANS Grid created in Pointwise software \ Hybrid unstructured \ Mapped elements on the surface \ Prism layers to simulate BL \ Tetra elements in the entire volume \ grid points 5nd 3AF International Conference on Applied Aerodynamics, 017 8

9 frequency [Hz] velocity [m/s] velocity [m/s] Verification by experimental data Supply pressure is varied to change the frequency of oscillation \ Frequency determined by FFT from side force oscillation 100 Exp. CFD supply pressure [psi] Suction velocity - Ws Supply pressure 10 frequency [Hz] Exp. CFD supply pressure [psi] 5nd 3AF International Conference on Applied Aerodynamics, Blowing velocity - Wb

10 Velocity magnitude 5nd 3AF International Conference on Applied Aerodynamics,

11 Velocities From pressure probes placed in the feedback tube and in the plane below the jet s exit 5nd 3AF International Conference on Applied Aerodynamics,

12 Velocities Velocity components \ Chord wise position of the maximum normal velocity at the jet s exit P = 3.71 psi P = 4.9 psi P = 7 psi P = 14. psi 5nd 3AF International Conference on Applied Aerodynamics, 017 1

13 Simplified boundary condition Significant effort has been done \ Different velocity profile on the surface BC \ Uniform \ Parabolic \ Modeling of the cavity shape or part of it \ Knowledge about the exit jet flow field to determine BC Surface boundary condition to simulate the SaOB \ Functional representation of the nozzle s oscillatory velocity \ Gaussian representation * * D. Schatzman, J. Wilson, L. Marom, V. Palei, A. Seifert and E. Arad: Suction and Oscillatory Blowing Interaction with Boundary Layers 5nd 3AF International Conference on Applied Aerodynamics,

$Simplified boundary condition Developed on basis of the time dependent flow variables at the nozzle s exit \ D Gaussian function defined by 5 parameters \ Ai, xi, yi, σ xi, σ yi 5nd 3AF$

14 Simplified boundary condition Developed on basis of the time dependent flow variables at the nozzle s exit \ D Gaussian function defined by 5 parameters \ Ai, xi, yi, σ xi, σ yi 5nd 3AF International Conference on Applied Aerodynamics, ) ( ) ( c b x ae x f i i y y x x N i i z y x z c ft e A V i y i x i i sin 1 * ),, ( * *

15 Simplified boundary condition 5nd 3AF International Conference on Applied Aerodynamics,

$has been achieved Deeper cross comparison is still on-going \ Cross flow conditions frequency [Hz] 5nd 3AF International Conference on Applied Aerodynamics, 017 16$

16 velocity [m/s] Simplified boundary condition Similar effect on the local flow field as full actuator Linear dependency of blowing velocity on oscillation frequency has been achieved Deeper cross comparison is still on-going \ Cross flow conditions frequency [Hz] 5nd 3AF International Conference on Applied Aerodynamics,

$Conclusion and outlook Significant reduction of the grid complexity can be achieved by using BC to simulate effect of SaOB \ Reduction of the$ $for low-speed and high-speed regimes \ Circulation control \ Drag reduction \ Buffet control 5nd 3AF International Conference on Applied$

17 Conclusion and outlook Significant reduction of the grid complexity can be achieved by using BC to simulate effect of SaOB \ Reduction of the computational resources and time Simplified boundary condition can be used within the entire range of the considered supply pressure \ Linear dependency of the blowing velocity on oscillation frequency BC enable to implement the AFC (SaOB) into the design process Application of this BC for low-speed and high-speed regimes \ Circulation control \ Drag reduction \ Buffet control 5nd 3AF International Conference on Applied Aerodynamics,

18 THANK YOU FOR YOUR ATTENTION! The presented results & the research leading to these results has received funding from the European Community's Seventh Framework Programme FP7/ , under grant agreement n , AFLONEXT project 18

Detailed simulation of turbulent flow within a suction and oscillatory blowing fluidic actuator

Center for Turbulence Research Annual Research Briefs 14 9 Detailed simulation of turbulent flow within a suction and oscillatory blowing fluidic actuator By J. Kim AND P. Moin 1. Motivation and objectives