摘要
We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-order low-dissipative finite difference operators with energy-preserving properties.No-slip,adiabatic boundary conditions are enforced at the surface of large particles(with diameters significantly larger than the local grid spacing)using a ghost-point immersed boundary method.Two-way coupling between the gas phase and small particles(with diameters proportional to the grid spacing)is accounted for through volumetric source terms for interphase momentum and energy exchange.A simple and efficient approach for collision detection between small and large particles is proposed.The framework is applied to simulations of planar shocks interacting with bidisperse distributions of particles with size ratios of approximately thirty.Particle dispersion and size segregation are reported and a simple analytical model for size segregation is proposed.
本文提出了一个用于模拟含有大尺寸比固体颗粒的黏性可压缩流的数值框架.该框架采用具有能量守恒特性的高阶低耗散有限差分算子对体积滤波的Navier-Stokes方程进行离散化.在大尺寸颗粒表面(其直径远大于局部网格间距)上通过虚拟点浸入边界方法强加无滑移、绝热边界条件.对于直径与网格间距相当的小颗粒,则通过相间动量与能量交换的体积源项实现气固两相双向耦合.综上,本文提出了一种简单有效的碰撞探测框架,用于研究小尺寸颗粒和大尺寸颗粒之间的相互作用.该框架被应用于平面冲击波与大约30倍尺寸比的双分散颗粒相互作用的模拟分析.结果展示了颗粒扩散和尺寸偏析现象,并提出了一个简化的尺寸偏析解析模型.
基金
This work used Expanse systems at UCSD through an allocation[PHY240089]from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)program
supported by U.S.National Science Foundation(Grant Nos.2138259,2138286,2138307,2137603 and 2138296).
