A progress report is given on the implications of inlet noise reduction on aircraft direct operating costs (DOC). It considers treated inlet rings, various other inlet noise reduction concepts, and forward-speed effects. The report was limited to relatively well-established approaches to inlet noise reduction, such as acoustic liners and fixed-geometry/high-subsonic-speed inlets which are the focus of considerable current research activity. All of the concepts discussed are of a "passive" nature, i.e., no moving parts or electrical feedback systems.
Advanced inlet duct noise reduction concepts
1976-01-01
Conference paper
No indication
English
Auxiliary power unit inlet duct assembly for mitigating noise
European Patent Office | 2017
|AUXILIARY POWER UNIT INLET DUCT ASSEMBLY FOR MITIGATING NOISE
European Patent Office | 2017
|