Tyre noise and in-wheel motor noise in FE simulations for Pass-By Noise Predictions 2023-01-1094
Pass-by noise measurement is mandatory for automotive manufacturers
for conformity of production. With evolving of pass-by noise requirements
(under 68 dB in 2024), all the stakeholders should be able to comply with this
criterion. OEMs, suppliers of passive acoustic treatments, road manufacturers
and tire manufacturers are concerned and should deploy efforts to provide
solutions for control of exterior noise. In this regard, simulations are
preferable over measurement campaigns as they can provide fast feedback on
passive exterior treatments for exterior noise control.
In the particular case of Lightyear vehicles, the main contributors to pass-by
noise are tyres and in-wheel motors. Considering that, a contribution of each
of these two sources of noise to pass-by noise will be described. Tyre sources
and motor sources will be replaced by simple monopole sources. The results of
this simulation will be compared to the pass-by noise measurements.
The goal of the simulation is to provide the best possible passive exterior
treatment, namely wheelhouse liners, under-engine shields, under-body
panels and under-trunk panels. To achieve this goal, Actran vibro-acoustic
Finite Element software is used to predict the noise at pass-by microphones.
The calculation process takes advantage of advanced techniques to optimize
the process. The acoustic transfer functions (TFs) from monopole sources to
microphones are calculated first. The TFs are computed in different conditions
considering or not acoustic treatments in different areas treated and
admittance values. To speed-up the computation, acoustic super elements are
used enabling a fast restart capability. A second step consists in
recombining these transfer functions with source strengths.
Finally optimal configuration(s) of the surface of acoustic treatments versus
acoustic gain is assessed.
Alina Lysak, Attila Kocsis
Noise and Vibration Conference & Exhibition
Finite element analysis
Simulation and modeling
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