An adaptive mixed formulation for 3D magnetostatics

An enhanced version gi a mixed field-based formulation for magnetostatics p reviously developed by the authors is presented and its features are discus sed. The formulation minimises the residual of the constitutive equation, a n exactly imposes Maxwell's equations with Lagrange multipliers. Finite ele ments satisfying the physical continuity properties for both the magnetic a nd the magnetic induction fields are used in the numerical approximations. The possibility of decoupling the formulation in two separate sets of equat ions is discussed. A preconditioned iterative method to solve the final alg ebraic linear system is presented. Finally, a very natural refinement indic ator is defined to guide nn adaptive mesh refinement procedure.