Improved Adaptive Particle Refinement in -SPH and Application to Flow Around Bluff Bodies Simulation in Different Reynolds Numbers

Particle refinement technique uses spatially varying particle distributions that focus fine resolution on areas of interest to improve accuracy and computational efficiency of the smooth particle hydrodynamics (SPH) method, but its stability at coarse/fine interfaces can be problematic. Aiming at this problem, this paper improved adaptive particle refinement (APR) technology by optimizing the interpolation method of the particle parameters in buffer area and correcting the kernel gradient of particles troubled with boundary truncation to eliminate the truncation error. Based on the improved APR adopted in delta-SPH, the numerical simulation of the viscous flows around the bluff bodies under different Reynolds numbers were carried out. Additionally, the wake flows and hydrodynamic coefficients of the bluff bodies were systematically analyzed, respectively. The validity of the improved model was verified by comparing with the values in experiment and related literature, respectively. The calculated hydrodynamic coefficient achieves good agreement with the experimental data and the wake flow phenomena observed in experiment are clearly captured. The method adopted in this paper is effective and reliable, and has certain reference value for the research of fluid dynamics fields.