Iterative Solver Based on Incomplete Cholesky Preconditioner for the Parallelisation of a Forging Simulation Software by Mesh Partitioning

A parallel implementation of the preconditioned conjugate residual (PCR) method is described. The method is used to solve the discretized generalised Stokes problem derived from the simulation of complex 2D axisymetrical hot metal forming process. We numerically show that the use of a simple diagonal block (BDS) preconditioner results in a high level of parallelism. Nevertheless in 2D, the iterative solver with BDS is much slower than the direct solver. Hence, better sequential and parallel preconditioner are studied, like incomplete factorisations ILU(0). It results in an almost twice faster parallel code, but with a lost in scalability due to the increase of communications between processors. E. Perchat, L. Fourment, and T. Coupez.