Differently from the flux tube elements of package Shapes.Leakage that are calculated from their geometry, this leakage reluctance is calculated with reference to the total reluctance of a useful flux path. Please refer to the Parameters section for an illustration of the resulting magnetic network. Exploiting Kirchhoff's generalized current law, the leakage reluctance is calculated by means of a coupling coefficient c_usefulFlux.
This element must not be used for dynamic simulation of electro-magneto-mechanical actuators, where the shape of at least one flux tube element with reluctance force generation in the useful flux path changes with armature motion (e.g., air gap). This change results in a non-zero derivative dG_m/dx of those elements permeance G_m with respect to armature position x, which in turn will lead to a non-zero derivative of the leakage permeance with respect to armature position. This would generate a reluctance force in the leakage element that is not accounted for properly. Shapes.Force.LeakageAroundPoles provides a simple leakage reluctance with force generation.