Matlab command | plot_Fr_space |
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Module | EM.pp |

Description | PLOT_FR_SPACE plots the airgap radial magnetic force per unit area as a function of space |

Parameters | |

Restrictions | |

See also | plot_Ft_space, plot_Fr_time, plot_Fr_fft2 |

### Result

The calculation of **Maxwell tensor** is an important output of **MANATEE software** electromagnetic model as it generates magnetic forces responsible for** electromagnetically-excited audible noise**.

This particular post processing plots the **radial force per unit area** experienced by the outer structure as a function of airgap angle, including the corresponding Fourier analysis:

One can see that it is negative because globally the outer stator tends to be pulled towards the inner rotor.

The largest harmonic (wavenumber) should correspond to r=2p (twice the number of pole pairs) and its magnitude should equal the DC component one (r=0). Note that **only the lowest force wavenumbers are important in magnetic noise and vibration process**.

Note that this 1D FFT graph gives only a partial view of the harmonics, as both space and time frequencies are involved in noise and vibration generation. A 2D Fourier transform of the radial force is available with plot_Fr_fft2.

To change the default plot options (e.g. time stamp of the plot, axis) you can read How to change post processing plot options ? article.

This graph helps identifying the space harmonics involved in radial magnetic pressure involved **noise and vibration behaviour of the electrical machine**.