Comparison of DLR and ISVR wave number decomposition technique

Abstract

DLR and ISVR independently developed techniques for the purpose of separating hydrodynamic and acoustic signal constituents in measurements with an axial microphone array. The DLR technique implements a spatial Fourier transform and bases on the work of Arguillat and Ehrenfried [1, 2]. The work was motivated by the objective to separate the hydrodynamic perturbations from measurements of of the mean power spectral density (PSD). At the ISVR a beamformer algorithm was developed [3, 4] and utilized for the mapping of the induct-sound eld into the far eld. A brief comparison of the dierent techniques is given. The nomenclature follows the paper abstract of Brian Tester [5]. In order to retain comparability to the DLR approach, the coordinate system and the formulation for axial wave numbers was used instead of propagation angles.