Modeling the effects of wind tunnel wall absorption on the acoustic radiation characteristics of propellers
Abstract
Finite element theory is used to calculate the acoustic field of a propeller in a soft walled circular wind tunnel and to compare the radiation patterns to the same propeller in free space. Parametric solutions are present for a 'Gutin' propeller for a variety of flow Mach numbers, admittance values at the wall, microphone position locations, and propeller to duct radius ratios. Wind tunnel boundary layer is not included in this analysis. For wall admittance nearly equal to the characteristic value of free space, the free field and ducted propeller models agree in pressure level and directionality. In addition, the need for experimentally mapping the acoustic field is discussed.
- Publication:
-
Thermophysical Aspects of Re-entry Flows
- Pub Date:
- July 1986
- Bibcode:
- 1986aiaa.confR....B
- Keywords:
-
- Acoustics;
- Finite Element Method;
- Radiation Absorption;
- Sound Waves;
- Turbofans;
- Wind Tunnel Walls;
- Flow Velocity;
- Propellers;
- Radiation Distribution;
- Wall Pressure;
- Acoustics