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)