Global active noise reduction method for rotor craft

Abstract

The invention discloses a global active noise reduction method for a rotor craft. The method comprises the steps of collection of noise sound pressure signals at rotor measuring points, rotor noise acoustical hologram sound field prediction, rotor noise reverse sound field reconstruction and adaptive sound field adjustment based on optimal phase search. Compared with an existing passive and active noise reduction method, the global active noise reduction method based on acoustical holography and sound field reconstruction does not need to change a rotor wing type or introduce a complex mechanical structure, and only needs to arrange a plurality of measuring devices and secondary sound sources around a machine body, so that the increase of system complexity and cost is avoided, and the method has higher practical value and a better noise reduction effect. In addition, compared with traditional rotor wing noise finite point local noise reduction based on a self-adaptive filtering algorithm, the noise reduction method based on acoustical holography and sound field reconstruction is better in consistency, and can realize real rotor wing global noise reduction.

Description

technical field [0001] The invention relates to the field of rotor aerodynamic noise, in particular to a global active noise reduction method based on acoustic holography and sound field reconstruction. Background technique [0002] Rotorcraft can take off and land vertically and fly at low altitude. The unique flight advantages make it widely used in both military and civilian fields, and will become the main carrier of urban air traffic in the future. The mission positioning of the rotorcraft includes but is not limited to battlefield launch, aerial geophysical survey, passenger service (such as air taxi), emergency ambulance, cargo service, smart city management, aerial media, etc. However, the aerodynamic noise generated by the interaction between the rotor of the aircraft and the air not only seriously affects the military concealment and detectability of the aircraft, but also causes greater environmental noise pollution and community disturbance. The aerodynamic nois...

AI Technical Summary

Problems solved by technology

It should be pointed out that this type of active noise control method needs to introduce complex mechanical structures or external excitations on the existing rotor system, which will further increase the complexity of the rotor system and affect the reliability and safety of the rotor.

[0004] Generally speaking, the practicability and feasibility of the existing active rotor noise control methods are not high, and it is difficult to effectively solve the problem of rotor aerodynamic noise suppression.

Images