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Magnetomotive device based on reluctance force

The Reluctance Force Actuator block models a generic magnetomotive device based on reluctance force.

The block is based on the following equations:

where

F | Reluctance force |

Φ | Flux in the magnetic circuit |

Reluctance | |

x | Thickness or length of the air gap |

μ_{0} | Permeability constant |

μ_{r} | Relative permeability of the material |

A | Cross-sectional area of the section being modeled |

u | Velocity |

Connections N and S are magnetic conserving ports, and connections C and R are mechanical translational conserving ports. The magnetic force produced by the actuator acts to close the gap, therefore the resulting force is negative when it acts from C to R.

The current excitation in the system is constant.

Only axial reluctance is modeled.

**Initial air gap**Thickness or length of air gap at the beginning of simulation. The default value is

`2`mm.**Minimum air gap**Minimal value of air gap, with the reluctance force acting to close the air gap. The parameter value has to be greater than 0. The default value is

`1e-4`mm.**Cross-sectional area**Area of the section being modeled. The default value is

`0.01`m^2.**Relative permeability of material**Relative permeability of the section material. The default value is

`1`.**Contact stiffness**Stiffness that models the hard stop at the minimum air gap position. The default value is

`10e6`N/m.**Contact damping**Damping that models the hard stop at the minimum air gap position. The default value is 500 N/(m/s).

Use the **Variables** tab to set the priority
and initial target values for the block variables prior to simulation.
For more information, see Set Priority and Initial Target for Block Variables.

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