A numerical study of the parameters controlling the viscous penalty method is investigated to better set up Particle-Resolved Direct Numerical Simulations (PR-DNS) of particulate flows. Based on this analysis, improve...A numerical study of the parameters controlling the viscous penalty method is investigated to better set up Particle-Resolved Direct Numerical Simulations (PR-DNS) of particulate flows. Based on this analysis, improvements of the methods are proposed in order to reach an almost second order convergence in space. The viscous penalty method is validated in Stokes regime by simulating a uniform flow past a fixed isolated cylinder. Moreover, it is also utilized in moderate Reynolds number regime for a uniform flow past a square configuration of cylinder and compared in terms of friction factor to the well-known Ergun correlation.展开更多
In this work,the modified Ghost Fluid Method is further developed to ap-ply to compressible fluid coupled to deformable structure,where the pressure in the structure or flow can vary from an initial extremely high mag...In this work,the modified Ghost Fluid Method is further developed to ap-ply to compressible fluid coupled to deformable structure,where the pressure in the structure or flow can vary from an initial extremely high magnitude(such that the solid medium can be under plastic compression)to a subsequently very low quantity(so that cavitation can occur in the fluid).New techniques are also developed in the definition of the ghost fluid status when the structure is under plastic deformation or when the flow is under cavitation next to the structure.Numerical results show that the improved MGFM for treatment of the fluid-deformable structure coupling works efficiently for all pressure ranges and is capable of simulating cavitation evolution and cavitation re-loading in conjunction with the employment of the isentropic one-fluid cavitation model.展开更多
文摘A numerical study of the parameters controlling the viscous penalty method is investigated to better set up Particle-Resolved Direct Numerical Simulations (PR-DNS) of particulate flows. Based on this analysis, improvements of the methods are proposed in order to reach an almost second order convergence in space. The viscous penalty method is validated in Stokes regime by simulating a uniform flow past a fixed isolated cylinder. Moreover, it is also utilized in moderate Reynolds number regime for a uniform flow past a square configuration of cylinder and compared in terms of friction factor to the well-known Ergun correlation.
文摘In this work,the modified Ghost Fluid Method is further developed to ap-ply to compressible fluid coupled to deformable structure,where the pressure in the structure or flow can vary from an initial extremely high magnitude(such that the solid medium can be under plastic compression)to a subsequently very low quantity(so that cavitation can occur in the fluid).New techniques are also developed in the definition of the ghost fluid status when the structure is under plastic deformation or when the flow is under cavitation next to the structure.Numerical results show that the improved MGFM for treatment of the fluid-deformable structure coupling works efficiently for all pressure ranges and is capable of simulating cavitation evolution and cavitation re-loading in conjunction with the employment of the isentropic one-fluid cavitation model.
