Correction techniques for the truncation of the source field in acoustic analogies

The truncation of the source field may induce large overpredictions in the acoustic field computed through acoustic analogies. A comparative study of different correction approaches proposed in the literature is carried out, considering three different techniques: correction terms based on a convection assumption, use of model extensions, and windowing techniques. It is shown that convection-based correction terms need to take into account noncompactness effects of the source field in order to yield accurate results. A modified correction term that includes these effects is derived, and its equivalence to the method of model extensions in the case Of purely convected flows is highlighted. Moreover, the performance of different windowing techniques is investigated. (C) 2008 Acoustical Society of America. [DOI: 10.1121/1.2999555]