Adaptive Mesh Refinement for Rotating Electrical Machines Taking into Account Boundary Approximation Errors

In this work we present an error estimator for a class of second order quasilinear elliptic problems in 2D. The computational domain consists of two parts—called rotor and stator in the framework of electrical motors—separated by a curvilinear interface. For the coupling of the rotor and the stator on the interface we use a Nitsche technique as described in Hollaus et al. (Nitsche-type mortaring for Maxwell’s equations, In: Progress in electromagnetics research symposium proceedings, Cambridge, pp 397–402, 5–8 July 2010). The residual error estimator is constructed similarly to the approach used in Houston et al. (IMA J Numer Anal 28:245–273, 2008) with adaptations due to the coupling strategy. The error estimator takes into account the polygonal approximation of the stator and the rotor using ideas from hierarchical error estimates.