Aiming at problem of the scanning phase error and the limited measurement aperture in the practical engineering application

propose two methods to analyze and solve the issues above

which are improved test array and algorithm optimization

using the method of snapshot measurement based on the plane array with digital microphones

instead of the traditional scanning measurement

the phase error is avoided

the limited aperture nearfield acoustical holography reconstruction error mechanism are analyzed in theory

A new method of acoustical holography named " limited aperture space extension + wavenumber domain iterative filtering" are proposed. Take a simply-supported infinite steel plate that under harmonic excitation as example

compare with the result from the conventional near-field acoustic holography

demonstrate the effectiveness of the algorithm

analyze on influence of the " 0" space range and the number of iterations on the reconstructing of the acoustic field. The rotor testbed is used as the device under test

The known fault is simulated by the rotor table. The applicability of the algorithm is verified by the scanning result of the sensor array with a single reference sensor. The simulation fault location is located accurately.