Nuclear Science and Engineering / Volume 193 / Number 11 / November 2019 / Pages 1219-1237
Technical Paper / dx.doi.org/10.1080/00295639.2019.1620052
Computational accuracy and resource consumption are two sides of the mesh-based neutron transport calculation, whose balance is a common concern in engineering application. To overcome the inflexibility of the multiblock (MB) refinement technique and the complexity of the adaptive-mesh-refinement (AMR) technique, this paper presents a MB-AMR–based neutron transport lattice Boltzmann method (LBM) for the first time, which is a development and in-depth study for the current nonuniform mesh technique. The neutron transport problems are solved using the LBM with finite Boltzmann scheme, and the mesh configuration is adaptively adjusted using the MB-AMR technique. The MB-AMR technique combines the simplicity of the MB technique and the flexibility of the AMR technique and overcomes their shortcomings. By using invariant blocks, the complicated tree structure used in the traditional AMR technique is eliminated. By adjusting the mesh configuration according to the calculation results adaptively, the inflexible of the MB technique is overcome. By using the finite Boltzmann scheme instead of the traditional LBM, the implementation is further simplified and the interface treatment between different blocks can be solved as inner nodes using streaming process. Based on the above advantages and the simplicity of the LBM, the difficulty of the AMR technique in neutron transport calculation has been greatly reduced. To verify the accuracy and flexibility of the proposed MB-AMR–based neutron transport LBM, five benchmark problems are simulated. Results show that the proposed neutron transport LBM can simulate the multigroup transient and steady-state neutron transport problems accurately and that the MB-AMR technique can adaptively adjust the mesh configuration flexibly and simply. This paper may provide some alternative perspectives to realize the nonuniform mesh–based neutron transport solution and a powerful technique for large-scale engineering.