Result

Airgap radial force as function of time

plot_Fr_time

In this example, the radial force contains a DC component and a large component at twice the electrical frequency. The DC component has no effect on magnetic acoustic noise and vibrations. The slotting effects are present at higher frequencies. This post processing illustrates the radial force seen by a fixed point in the airgap, so there is no information on the spatial distribution of the force.

The radial force as a function of the airgap angle can be plotted with plot_Fr_space. To fully understand the magnetic vibration generation process, it is important to analyze both the frequency and wavenumber of the force waves. A 2D FFT is therefore more relevant, for instance plot_Fr_fft2.