PIV/Phased Array/Far-Field Noise Measurements of a Low-Noise Top-Mounted Propulsion Installation for a Supersonic Airliner

Bridges, James ; Cluts, Jordan ; Podboy, Gary ; Wernet, Mark

关键词: PARTICLE IMAGE VELOCIMETRY;    PHASED ARRAYS;    FAR FIELDS;    NOISE MEASUREMENT;    ACOUSTIC ATTENUATION;    SHIELDING;    LOW NOISE;    PROPULSION SYSTEM CONFIGURATIONS;    PLANFORMS;    NOZZLE DESIGN;    SUPERSONIC AIRCRAFT;    PLUMES;    EXHAUST SYSTEMS;    NOISE REDUCTION;    NOISE PREDICTION;    EFFECTIVE PERCEIVED NOISE LEVELS;   

RP-ID  :  GRC-E-DAA-TN67394

学科分类：航空航天科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

A model-scale exhaust system was tested to validate low-noise concepts and noise prediction methods. The tests involved far-field acoustics, translating phased array, and particle image velocimetry; this report covers the far-field acoustic measurements. Data were acquired for a series of nozzles with different chevron designs, both uninstalled and installed on a representative aircraft planform. The impact of the various chevron treatments on the far-field noise was documented, along with the impact of the pylon and planform. For the baseline nozzle, installation produced a 2 EPNdB (Effective Perceived Noise in deciBels) reduction, as assumed in system studies. Chevrons were used to shift noise sources upstream to maximize the installation benefits and to reduce unshielded sources downstream. These resulted in reductions of 4-5 EPNdB...