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Boeing - St.LouisMarch 7, 2006
Plasma Actuators for Landing Gear
Noise Control*
F. O. Thomas, A. Kozlov, T.C. Corke
* Supported by NASA Langley NAG1-03076
AIAA -2005-3010 Presented at 11th AIAA / CEAS Aeroacoustics Conference,
May 25, 2005.
Langley Research Center
Boeing - St.LouisMarch 7, 2006
radiated noise
radiated noise
U
plasma actuators on
plasma actuatorsplasma actuators
U
no actuation
The Plasma Fairing Concept
Boeing - St.LouisMarch 7, 2006
Cylinder Model Utilizing Four Actuators
1. Quartz cylinder wall forms adielectric barrier: ( thickness of 2.5 mm)
2. Copper foil electrode (6.4 mm)
3. Encapsulated electrode:lead foil (25.4 mm)
1. Inner insulation (7 layers of 0.005” thick Kapton tape)
5. Regions of plasma formation
• Sinusoidal A.C. voltage is applied at 8.1 kV rms and f = 10 kHz.
Boeing - St.LouisMarch 7, 2006
Cylinder Model Utilizing Four Actuators
Boeing - St.LouisMarch 7, 2006
Single Actuator-Induced Mean Velocity Field
Plasma actuator
No external flow
Plasma-inducedCoanda effect
Boeing - St.LouisMarch 7, 2006
Dual Actuator-Induced Mean Velocity
No external flow
Plasma actuators
Boeing - St.LouisMarch 7, 2006
Steady Actuation : ReD = 30,000
Boeing - St.LouisMarch 7, 2006
Wake Velocity Auto-spectra (ReD = 30,000)
1x10
-3
1x10
-2
1x10
-1
1x10
0
1x10
1
1x10
2
1x10
3
1x10
0
1x10
1
1x10
2
1x10
3
FREQUENCY (Hz)
PLASMA OFF
STEADY PLASMA
Boeing - St.LouisMarch 7, 2006
ReD=30,000Unsteady Actuation: 48 Hz (StD=1)
Boeing - St.LouisMarch 7, 2006
ReD=30,000Vorticity Unsteady Actuation: 6Hz
Boeing - St.LouisMarch 7, 2006
Unsteady Symmetric Actuation: ReD = 30,00048 Hz., 25% Duty Cycle: Vorticity
Boeing - St.LouisMarch 7, 2006
Unsteady Symmetric Actuation: ReD = 30,00025% Duty Cycle,
f =48 Hz (StD=1)