control and scaling of radius-vectored turbulent boundary layers using plasma actuators
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60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Control and Scaling of Radius-Vectored Turbulent Boundary Layers
Using Plasma Actuators
T. Corke and R. Hewitt
Center for Flow Physics and ControlAerospace and Mechanical Engineering
University of Notre Dame
60th Annual Meeting of the APS Division of Fluid DynamicsSalt 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 DynamicsSalt Lake City, Utah
Motivation: Airframe Noise Control
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Frequency (Hz)
Sou
nd P
ress
ure
Leve
l / F
requ
ency
(dB
/Hz)
Steady
UnsteadyPlasma OFF
x/D = 1.5
Flush-mountedmicrophone
-13.3 dB
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
SDBD Plasma Actuators
Prog. Aero. Sci., 2007 (In press).
Ref: AIAA J., 42, 3, 2004
exposed electrode
dielectric
AC voltage source
covered electrode
substrate
Induced Flow
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Coanda Effect: No external flow
Plasma actuator (90 deg.)
Plasma-inducedCoanda effect
Plasma actuators
Plasma Actuators (90 & 270 deg.)
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Coanda EffectNo External Flow
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Experimental Approach:Effect of External Flow
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Experimental Setup
Flow
Light Sheet
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Particle Visualization
R=10.4 cm (4.1in)U∞=6 m/s
Baseline
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Particle Visualization
15.2kV
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Particle Visualization
18.6kV
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Particle Visualization
22.4kV
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Particle Visualization
25.5kV
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Particle Visualization
28.5kV
60th Annual Meeting of the APS Division of Fluid DynamicsSalt 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 DynamicsSalt Lake City, Utah
Results: Separation Location
Summary:
• Min. Sensitivity to FS Velocity.
• Baseline separation location moves upstream with decreasing radius.
• Linear dependence of xs on actuator voltage
xs
Decreasing R
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Flow Turning Angle
Summary:
• Min. Sensitivity to FS Velocity.
• Response of Actuator increases with decreasing radius
=xs/R
Decreasing R
60th Annual Meeting of the APS Division of Fluid DynamicsSalt Lake City, Utah
Results: Flow Turning Angle
Decreasing R
60th Annual Meeting of the APS Division of Fluid DynamicsSalt 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.
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