Objectives

Acoustic noise and vibration levels must be carried with fine discretization speed to catch all resonances. This module of MANATEE software speeds-up set-up and post processing of variable-speed e-NVH calculations using quasi-static approach.

Description

The modules VAR.QS compiles several fixed-speed steady state electromagnetic and vibroacoustic simulations with varying supply based on specified control strategy (e.g. constant flux, torque/speed curve, import of current etc), with the possibility to model non-linear run-ups.

All NVH post processing of WF.BS module are extended to variable speed (overall SPL/SWL as a function of speed, noise and vibration waterfalls or spectrograms, order tracking analysis, variable speed modal participation factors, force / vibration / noise spatiograms, operational deflection shapes).

Example of noise spectrogram obtained by MANATEE quasi static variable speed mode on EV HEV NVH application

Technical details

Contrary to transient approach of VAR.TR module, all the quantities are here assumed to be in steady state and a Fast Fourier Transform is used. Windowing or anti-aliasing filters can be used to reduce spectral leakage.

Graphical post-processing

The complete list of plot commands is available on MANATEE plot commands webpage. The following visualizations are more particularly related to this module:

• A-weighted sound pressure level spectrogram (plot_VS_ASPL_spectrogram)
• Order analysis (plot_VS_ASWL_order_analysis)
• A-weighted sound power level per magnetic force wavenumber (plot_VS_ASWL_spatiogram)
• Radial force harmonics spatiogram (plot_VS_Fr_spatiogram)
• Modal contribution at variable speed (plot_VS_ASWL_modal_cont)