Design of SFR fluidic diode axial port using topology optimization

A fluidic diode is a passive component that direct natural circulation during Loss of Forced Convection (LOFC) in the hybrid-type SFRs. In order to enhance the performance (diodicity) of the existing vortex-type fluidic diode (FD) design, topology optimization, a mathematical method to optimize material distribution in a design domain, is applied to the axial port. In this paper, the topology optimization is conducted for a 2-D axisymmetric domain and two designs with different aspect ratios are finally selected. In this process, design simplification and modification are also conducted based on sensitivity study. Performance of the final optimized designs are validated using detailed 3-D CFD analysis for various parameters, such as Reynolds numbers, entrance lengths, and turbulence models. It is found that the diodicity of the optimized axial port ranges from 1.7 to 2.3 for the low aspect-ratio design (design A) and from 3.7 to 4.5 for the high aspect-ratio design (design B). Friction loss coefficients for the final designs are evaluated for both forward and backward flows using the CFD analysis.