With support of Federation Computing in JASMIN,two serial codes named radiation hydrodynamics code RH2D and particle transport code Sn2D as Federal members are concatenated to an integrated program RHSn2D,which uses efficiently thousands of processors to simulate a multiphysics composition system.Federal members of RHSn2D have mesh patches and parallel algorithms respectively,encapsulating parallel communication between them based on JASMIN.For a typical model discretized by 90 720 meshes,100 patches in RH2D,2 835 patches in Sn2D,48 directions and 16 energy groups,it shows that the integrated program RHSn2D achieves parallel efficiency of 36% with 1 024 processors.

For discontinuous finite element method of time-dependent neutron transport equations in 2D cylindrical geometry,a parallel algorithm with interface prediction and correction is designed.Numerical experiments show that the parallel algorithm with explicit prediction and implicit correction has good precision,parallelism and simplicity.Compared with parallel algorithm based on implicit scheme,the new parallel algorithm has higher parallel efficiency with accuracy-preserving.Especially,it achieves super-linear speedup on hundreds of processors for large-scale problems.

We analyze domain decomposition and priority queuing algorithms for neutron transport equations with 2-D cylindrical geometry. A domain decomposition method based on the lowest surface-to-volume aspect and a corresponding priority queuing algorithm are proposed.Numerical experiments indicate that the method exhibits perfect speedup with hundreds of processors on parallel computers with high network latency.