Abstract: Buzz saw noise propagates through inlet of aviation engine at high power settings. An inlet of aviation engine with blowing slot blowing air grazing over surface of buzz saw lining at speeds higher than inlet mean air flow speed for buzz saw noise control.

Abstract: The present patent disclosure presents a class of patent aviation engine inlets using tangential blowing airflow grazing over buzz saw lining surface to prevent buzz saw noise from propagation out of the engine inlet, to alleviate airport noise problem and to reduce airplane cabin noise level for passenger comfort. The robustness of the concept of tangential blowing in the improvement of the attenuation of buzz saw tones by buss saw lining is that, practically, the significant buzz saw tones are eliminated. Tangential Blowing also serves to rectify undesirable inlet flows such as excessive boundary layer growth or flow separation that caused by cross wind, high angle of attack of inlet inflow during low flight speed operations of the aircraft. The relief of the inlet flow complications at low flight speed renders the airplane designer the freedom to shape/re-shape the engine inlet/nacelle contours for minimum cruise drag and best airplane trip fuel economy.

Abstract: Gaseous-fluid supply system for a general industrial power machinery application and a class of laboratory noise research and development comprises three subsystems, namely a gaseous-fluid delivery subsystem, a gaseous-fluid settling subsystem and a gaseous-fluid duct subsystem. Each subsystem must satisfy a set of fluid dynamic requirements determined by the situation in hand. For noise abatement application and research, an addition set of self-noise requirements must also be satisfied. An embodiment of a quiet air supply device for an aviation fan engine inlet noise abatement application using tangential blowing is also described. Acoustic treatment of the quiet air supply device is such that the self-noise of the supply air is low. The fluid dynamic quality of the supply air is such that the tangential blowing would not cause the aviation fan engine inlet noise source to increase.

Abstract: An aero-acoustic aviation engine inlet with a single air blowing slot or multiple air blowing slots flows air over one or more segments of inlet acoustic lining surfaces at speeds that are higher than the inlet mean air flow speed, for aggressive inlet noise abatement.

Abstract: An aero-acoustic aviation engine inlet with a single air blowing slot or multiple air blowing slots flows air over one or more segments of inlet acoustic lining surfaces at speeds that are higher than the inlet mean air flow speed, for aggressive inlet noise abatement.