Numerical evaluation of source–receiver transfer functions with the Fast Multipole Boundary Element Method for predicting pass-by noise levels of automotive vehicles

Noise source characteristics in the ISO 362 vehicle pass-by noise test: Literature review

“…Such methods can analyse the pass-by noise characteristics of a vehicle in its early development stage, thus, reducing the experimental effort [62]. The neural networks technique and the Boundary Element Method (BEM) can be categorised within these approaches.…”

“…Sufficient computer resources are important prerequisites for the satisfactory performance of a BEM simulation. Mostly, a tradeoff between model accuracy and available computer facilities has to be made [62,65]. For the prediction of vehicle pass-by noise, a highly complex model would have been to be set up which automatically leads to a requirement for high performance computing.…”

“…If a whole vehicle is to be modelled for the analysis of exterior noise propagation, the number of elements is enormous and, hence, the calculation time increases heavily. Hence, this method is not applicable in practice for higher frequencies than 500 Hz [62]. Another aspect of concern is the frequency resolution, which increases the computation time the higher it is.…”

“…Another aspect of concern is the frequency resolution, which increases the computation time the higher it is. It may be possible to estimate the transfer function by a small number of frequency data points, however, the quality of the transfer function may be compromised [62].…”

“…The Fast Multipole Boundary Element Method (FMBEM) can overcome the trade-off of the limited maximum frequency versus excessive computation time of the traditional BEM [62]. In the application of FMBEM, the structural/acoustic model is subdivided into several clusters.…”