NECP-X中角度与特征线并行的研究与实现

Long computing time and abundant memory requirement are two most critical issues for the method of characteristics (MOC) when applied for the three-dimensional whole-core transport calculation. The massive parallel is an effective method to solve these problems. The traditional parallel strategy based on space decomposition is limited by its degree of parallelism when solving the smaller size problem, which means it can not take full advantage of parallel resources. In this paper, a multilevel parallel of angle and characteristic ray was developed based on the space parallel implemented in the high-fidelity neutronics code NECP-X. To get good load balance of angle parallel, a greedy algorithm was applied, and to save memory in the ray parallel, a dynamic scheduling feature within shared memory architectures was used. The numerical results show that the parallel efficiency of the angle and characteristic ray in NECP-X is high. And it further expands the parallel degree based on the special decomposition parallelism.