numerical method for 2D-unsteady fluid flow is proposed in this paper,which is based on the common lagrange quadrilateral grid (primary grid) andreconstructed a series of secondary grid. The computational scheme on tw...numerical method for 2D-unsteady fluid flow is proposed in this paper,which is based on the common lagrange quadrilateral grid (primary grid) andreconstructed a series of secondary grid. The computational scheme on two-seriesgrid can resist effectively the intersection of grid.展开更多
This paper deals with time dependent performance characteristics of cavitating hydrofoils, the flow around which has been simulated using pressure-based finite volume method. A bubble dynamics cavitation model was use...This paper deals with time dependent performance characteristics of cavitating hydrofoils, the flow around which has been simulated using pressure-based finite volume method. A bubble dynamics cavitation model was used to investigate the unsteady behavior of cavitating flow and describe the generation and evaporation of vapor phase. For choosing the turbulence model and mesh size a non cavitating study was conducted. Three turbulence models such as Spalart-Allmaras, Shear Stress Turbulence （SST） κ-ω model, Re-Normalization Group （RNG） κ-ε model with enhanced wall treatment are used to capture the turbulent boundary layer along the hydrofoil surface. The cavitating study presents an unsteady behavior of the partial cavity attached to the foil at different time steps for σ = 0.8 and σ = 0.4. Moreover, this study is focused on cavitation inception, the shape and general behavior of sheet cavitation, lift and drag forces for different cavitation numbers.展开更多
Based on the finite element method(FEM), some iterative methods related to different Reynolds numbers are designed and analyzed for solving the 2D/3D stationary incompressible magnetohydrodynamics(MHD) numerically. Tw...Based on the finite element method(FEM), some iterative methods related to different Reynolds numbers are designed and analyzed for solving the 2D/3D stationary incompressible magnetohydrodynamics(MHD) numerically. Two-level finite element iterative methods, consisting of the classical m-iteration methods on a coarse grid and corrections on a fine grid, are designed to solve the system at low Reynolds numbers under the strong uniqueness condition. One-level Oseen-type iterative method is investigated on a fine mesh at high Reynolds numbers under the weak uniqueness condition. Furthermore, the uniform stability and convergence of these methods with respect to equation parameters R_e, R_m, S_c, mesh sizes h, H and iterative step m are provided. Finally, the efficiency of the proposed methods is confirmed by numerical investigations.展开更多
文摘numerical method for 2D-unsteady fluid flow is proposed in this paper,which is based on the common lagrange quadrilateral grid (primary grid) andreconstructed a series of secondary grid. The computational scheme on two-seriesgrid can resist effectively the intersection of grid.
文摘This paper deals with time dependent performance characteristics of cavitating hydrofoils, the flow around which has been simulated using pressure-based finite volume method. A bubble dynamics cavitation model was used to investigate the unsteady behavior of cavitating flow and describe the generation and evaporation of vapor phase. For choosing the turbulence model and mesh size a non cavitating study was conducted. Three turbulence models such as Spalart-Allmaras, Shear Stress Turbulence （SST） κ-ω model, Re-Normalization Group （RNG） κ-ε model with enhanced wall treatment are used to capture the turbulent boundary layer along the hydrofoil surface. The cavitating study presents an unsteady behavior of the partial cavity attached to the foil at different time steps for σ = 0.8 and σ = 0.4. Moreover, this study is focused on cavitation inception, the shape and general behavior of sheet cavitation, lift and drag forces for different cavitation numbers.
基金National Natural Science Foundation of China (Grant Nos. 11271298 and 11362021)
文摘Based on the finite element method(FEM), some iterative methods related to different Reynolds numbers are designed and analyzed for solving the 2D/3D stationary incompressible magnetohydrodynamics(MHD) numerically. Two-level finite element iterative methods, consisting of the classical m-iteration methods on a coarse grid and corrections on a fine grid, are designed to solve the system at low Reynolds numbers under the strong uniqueness condition. One-level Oseen-type iterative method is investigated on a fine mesh at high Reynolds numbers under the weak uniqueness condition. Furthermore, the uniform stability and convergence of these methods with respect to equation parameters R_e, R_m, S_c, mesh sizes h, H and iterative step m are provided. Finally, the efficiency of the proposed methods is confirmed by numerical investigations.
