Recommendations for Flux 2D

As seen previously, this document aims to determine the best combination between the number of cores used and the choice of the solver to save as much time and memory as possible during solving.

For Flux 2D, we use the two machines below by varying the mesh to increase the number of nodes in order to, recommend the right solver and the right number of cores according to the number of mesh nodes.

Figure 1. Both machines used by Flux 2D for the recommendations


Machine (a) is used for Magnetostatic and Transient Magnetic applications; it is a three-phase permanent magnet synchronous machine with 8 poles. In Magneto-Transient, the magnets are considered as solid conductors, and the machine is fed by a circuit coupling.

Machine (b) is used in Steady-State AC magnetic application, it is an induction machine with 2 poles also powered by a circuit coupling.

Several simulations are therefore launched with a different mesh (from the coarsest to the finest) with each time a number of cores and a different solver in order to draw up a table recommending the best choices.

Figure 2. Evolution of the mesh in a rotor slot of the induction machine with (a) a coarse mesh and (b) a fine mesh


Several recommendations are provided in the tables below for each of the Flux 2D applications (Transient Magnetic, Steady-State AC magnetic, and Magnetostatic):

Magnetostatic project
Number of nodes in the mesh 0 - 100k 100k - 600k 600k - 1.5M 1.5M +
Recommended number of cores 1 2 4 4 to 8
Minimal memory required 1 GB 2 GB 4 GB 6+ GB
Recommended linear solver Direct (MUMPS)
Steady-State AC magnetic project
Number of nodes in the mesh 0 - 200k 200k - 500k 500k - 1.5M 1.5M - 5M 5M +
Recommended number of cores 1 2 4 8
Minimal memory required 1 GB 2 GB 4 GB 12 GB 16+ GB
Recommended linear solver Direct (MUMPS)
Transient Magnetic Project
Number of nodes in the mesh 0 - 100k 100k - 400k 400k - 1.5M 1.5M +
Recommended number of cores 1 2 4 4 to 8
Minimal memory required 500 MB 1 GB 2 GB 4+ GB
Recommended linear solver Direct (MUMPS)