Nearfield acoustic holography in a moving medium is a technique which is typically suitable for sound sources identification in a flow.In the process of sound field reconstruction,sound pressure is usually used as the...Nearfield acoustic holography in a moving medium is a technique which is typically suitable for sound sources identification in a flow.In the process of sound field reconstruction,sound pressure is usually used as the input,but it may contain considerable background noise due to the interactions between microphones and flow moving at a high velocity.To avoid this problem,particle velocity is an alternative input,which can be obtained by using laser Doppler velocimetry in a non-intrusive way.However,there is a singular problem in the conventional propagator relating the particle velocity to the pressure,and it could lead to significant errors or even false results.In view of this,in this paper,nonsingular propagators are deduced to realize accurate reconstruction in both cases that the hologram is parallel to and perpendicular to the flow direction.The advantages of the proposed method are analyzed,and simulations are conducted to verify the validation.The results show that the method can overcome the singular problem effectively,and the reconstruction errors are at a low level for different flow velocities,frequencies,and signal-to-noise ratios.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11804002)the University Science Research Project of Anhui Province,China(Grant Nos.KJ2019A0792 and KJ2019A0797)the Anhui Jianzhu University Research Project(Grant No.2018QD06)。
文摘Nearfield acoustic holography in a moving medium is a technique which is typically suitable for sound sources identification in a flow.In the process of sound field reconstruction,sound pressure is usually used as the input,but it may contain considerable background noise due to the interactions between microphones and flow moving at a high velocity.To avoid this problem,particle velocity is an alternative input,which can be obtained by using laser Doppler velocimetry in a non-intrusive way.However,there is a singular problem in the conventional propagator relating the particle velocity to the pressure,and it could lead to significant errors or even false results.In view of this,in this paper,nonsingular propagators are deduced to realize accurate reconstruction in both cases that the hologram is parallel to and perpendicular to the flow direction.The advantages of the proposed method are analyzed,and simulations are conducted to verify the validation.The results show that the method can overcome the singular problem effectively,and the reconstruction errors are at a low level for different flow velocities,frequencies,and signal-to-noise ratios.
