Manatee software offers powerful tools to identify the root cause of e-NVH issues. One of this tools is the linear contribution plot which allows to quickly visualize the linear contribution of each load case to the overall noise or vibration and which is expressed in percentage.
For instance, the first graph shows that the Sound Power Level in dBA at 3000 rpm is driven at ~48% by loadcase r=-2, stator, radial (forces applied on the stator in radial direction with a wavenumber r=-2) and at ~47% by loadcase r=-2, stator, circ. (forces applied on the stator in circumferential direction with a wavenumber r=-2).
Note that in dB/dBA, a 50% linear contribution corresponds to a 3dB contribution.
The contribution plot can be used by mechanical engineers to easily identify the root cause of the e-NVH issue, whether it is air-borne or structure-borne, radial or circumferential.
An automatic split of internal/external and radial/circumferential load cases is also available through the “Split contributions” button to understand whether the e-NVH issue is air-borne or structure-borne, radial or circumferential along the speed.