Analytical study of the effects of wind tunnel turbulence on turbofan rotor noise
Abstract
An analytical study of the effects of wind tunnel turbulence on turbofan rotor noise was carried out to evaluate the effectiveness of the NASA Ames 40 by 80-foot wind tunnel in simulating flight levels of fan noise. A previously developed theory for predicting rotor/turbulence interaction noise, refined and extended to include first-order effects of inlet turbulence anisotropy, was employed to carry out a parametric study of the effects of fan size, blade number, and operating line for outdoor test stand, NASA Ames wind tunnel, and flight inlet turbulence conditions. A major result of this study is that although wind tunnel rotor/turbulence noise levels are not as low as flight levels, they are substantially lower than the outdoor test stand levels and do not mask other sources of fan noise.
- Publication:
-
American Institute of Aeronautics and Astronautics Conference
- Pub Date:
- June 1980
- Bibcode:
- 1980aiaa.confQ....G
- Keywords:
-
- Jet Aircraft Noise;
- Noise Prediction (Aircraft);
- Noise Reduction;
- Turbofan Engines;
- Turbulence Effects;
- Wind Tunnel Tests;
- Exhaust Gases;
- Flight Conditions;
- Noise Intensity;
- Structural Design;
- Turbine Wheels;
- Acoustics