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Control and Scaling of Radius-Vectored Turbulent Boundary Layers Using Plasma Actuators. T . Corke and R. Hewitt Center for Flow Physics and Control Aerospace and Mechanical Engineering University of Notre Dame. Objectives:.
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Control and Scaling of Radius-Vectored Turbulent Boundary Layers Using Plasma Actuators T. Corke and R. Hewitt Center for Flow Physics and Control Aerospace and Mechanical Engineering University of Notre Dame 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Objectives: • Investigate physics and scaling of SDBD Plasma Actuators for flow separation control on TE radii. • Parameters: Radius, TBL thickness, free-stream speed. • Develop designs for flow separation control associated with airframe noise. 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Motivation: Airframe Noise Control -13.3 dB 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
dielectric exposed electrode covered electrode substrate AC voltage source SDBD Plasma Actuators Induced Flow Ref:AIAA J., 42, 3, 2004 Prog. Aero. Sci., 2007 (In press). 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Coanda Effect: No external flow Plasma actuator (90 deg.) Plasma Actuators (90 & 270 deg.) Plasma-induced Coanda effect Plasma actuators 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Coanda Effect No External Flow 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Experimental Approach: Effect of External Flow 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Experimental Setup Light Sheet Flow 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Particle Visualization Baseline R=10.4 cm (4.1in) U∞=6 m/s 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Particle Visualization 15.2kV 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Particle Visualization 18.6kV 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Particle Visualization 22.4kV 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Particle Visualization 25.5kV 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Particle Visualization 28.5kV 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Surface Flow Visualization • Measurements of separation location was done using surface flow visualization • Mixture of evaporating oil and china clay. • Applied on radius surface • Oil moves according to local wall shear stress. 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Separation Location xs • Summary: • Min. Sensitivity to FS • Velocity. • Baseline separation • location moves • upstream with • decreasing radius. • Linear dependence of • xs on actuator voltage Decreasing R 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Flow Turning Angle =xs/R Decreasing R • Summary: • Min. Sensitivity to FS • Velocity. • Response of Actuator • increases with • decreasing radius 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Results: Flow Turning Angle Decreasing R 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah
Summary: • SDBD plasma actuators effective in controlling flow separation around a trailing-edge radius in which the approaching flow is a turbulent boundary layer. • Minimum Sensitivity to Free-stream Velocity. • Baseline separation location moves upstream with decreasing radius. • Linear dependence of xs on actuator voltage. • Response of Actuator increases with decreasing radius. • Minimum sensitivity to TBL thickness. • Up to 50% recovery of wake momentum in experiment. • Smaller radii more effective. 60th Annual Meeting of the APS Division of Fluid Dynamics Salt Lake City, Utah