Adaptive Mesh Refinement for Neutron Transfer With Lattice Boltzmann Scheme

This paper presents a novel lattice Boltzmann (LB) model for neutron transfer and a block-structured adaptive-mesh-refinement (SAMR) technique for proposed LB model. By discretizing the general Boltzmann equation, the LB model for neutron transfer is established and the corresponding parameters are obtained. The SAMR technique removes the requirement of tree-type data structure in traditional adaptive-mesh-refinement technique and adjusts the time step adaptively and identically in all blocks. By applying the node-type distribution function, the needs for rescaling the distribution functions is eliminated. To solve the discontinuities of scalar flux at fine-coarse blocks interface, a novel technique is presented which treats the inner boundary condition by streaming process of LB method. Simulation results show good accuracy and efficiency of the proposed neutron LB model with SAMR technique. This paper may provide a powerful technique for large engineering calculation.