APPLICATION OF GENERALIZED NEAR-FIELD ACOUSTICAL-HOLOGRAPHY TO SCATTERING OF PROBLEMS

Generalized near-field acoustical holography (GENAH) is applied to scattering problems, making use of its wavelength-limitation-free characteristic in the reconstruction process. GENAH signal processing is directly adapted for the reconstruction of the scattered field, while a method to extract the scattered-pressure hologram is independently proposed to create scattering GENAH. The measurement of the near field of a scatterer yields the superimposed incident and scattered fields. Their decomposition is carried out by subtracting the incident-pressure hologram from the superimposed-pressure hologram in K space. The validity of this decomposition method was demonstrated by comparing the experimental and theoretical results of finite submerged shells. Reconstruction of shell-surface vibration induced by scattering displayed a reasonable result.