Experimentally determined aeroacoustic performance and control of several sonic inlets
Abstract
Low speed wind tunnel tests were conducted to determine the aeroacoustic performance of several model sonic inlets. The results were analyzed to indicate how inlet aeroacoustic characteristics were affected by inlet design and operating conditions. A system for regulating sonic inlet noise reduction was developed and tested. Results indicate that pressure losses at forward velocity may be substantially less than those at static conditions. This is particularly true for translating centerbody inlets with the centerbody extended in the approach and landing position. Operation to simulated takeoff incidence angles of 50 degrees was demonstrated with good inlet performance. Inlet sound pressure level reduction was regulation was regulated to within approximately + or - 1 dB by controlling inlet surface static pressure measured at the diffuser exit.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- June 1975
- Bibcode:
- 1975STIN...7529353M
- Keywords:
-
- Engine Inlets;
- Inlet Pressure;
- Noise Reduction;
- Wind Tunnel Tests;
- Aerodynamic Characteristics;
- Free Flow;
- Performance Tests;
- Pressure Reduction;
- Fluid Mechanics and Heat Transfer