Combined Method of Near Field Acoustic Holography and Focused Beamforming for Noise Source Identification in Enclosed Space

Noise control of vehicle cabins has been given high consideration owing to the increasing demands for comfort of ship vehicles. Noise source identification is the precondition of noise control. Conventional methods of noise source identification are mainly applied in free fields. The performance of noise source identification methods will be seriously decreased in enclosed space due to the effect of sound reflection. Noise source identification in enclosed space based on double cylindrical array is researched in this paper. The effect of reflection sound is removed by using the sound field separation technique. The combined method of near field acoustic holography and focused beamforming for noise source identification is proposed to identify noise sources having high and low frequencies. The performance of the proposed method is studied by simulation, and the experiment is carried out in the submarine cabin model to verify the feasibility of the proposed method. The researching results shows that the effect of reflection sound can be removed using sound field separation technique based on double cylindrical array, and the high-resolution identification for high and low frequency signals can be obtained using the combined method of near field acoustic holography and focused beamforming.