The incomplete reception error in acoustic analogy integral with source time domain algorithm

Abstract

There are two algorithms to solve the retarded time equation in the acoustic analogy. One is the classic retarded time method, and the other is the source time domain algorithm or the advanced time approach. The latter is more effective and simple than the former. However, difficulties may arise in the reconstruction of the acoustic signal in the observer time domain. The signal interpolation in every observer time step and a completeness check at the end are necessary for the reconstruction. In addition, two error regions which cannot to be ignored in frequency domain are generated by the latter. They are called the incomplete reception error. It is the main purpose of present work to analyze the formation process and characteristics of the incomplete reception error. Then the analysis is tested with a simplified model and the numerical results show that there are some spurious numerical oscillations in frequency domain if the incomplete reception regions are not removed. Finally, the difference between the method of directly removing the incomplete reception regions and the standard acoustic signal post-processing method is compared. The comparison results show that the method of removing incomplete reception regions directly is better.

Keywords

Aeroacoustics acoustic analogy source time domain algorithm Formulation 1C acoustic signal reconstruction

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