In this paper, a numerical model is established. A modified N-S equation is used as a control equation for the wave field and porous flow area. The control equations are discreted and solved by the finite difference m...In this paper, a numerical model is established. A modified N-S equation is used as a control equation for the wave field and porous flow area. The control equations are discreted and solved by the finite difference method. The free surface is tracked by the VOF method. The pressure field and velocity field of the whole flow area are solved by the reiterative iteration method. Finally, compared with the physical model test results of wave flume, the numerical model established in the present study is validated.展开更多
In this paper, the supersonic chemically reacting mixing layer is simulated with the third order ENN scheme, based on the Navier-Stokes equations, containing transport equations of all species. The numerical results s...In this paper, the supersonic chemically reacting mixing layer is simulated with the third order ENN scheme, based on the Navier-Stokes equations, containing transport equations of all species. The numerical results show that the thickness of mixing layer increases gradually along the flow direction, and that the Kelvin-Helmholtz, instabilities may not exist in mixing layer flows.展开更多
The multi-dimensional system of nonlinear partial differential equations is considered. In two-dimensional case, this system describes process of vein formation in higher plants. Variable directions finite difference ...The multi-dimensional system of nonlinear partial differential equations is considered. In two-dimensional case, this system describes process of vein formation in higher plants. Variable directions finite difference scheme is constructed. The stability and convergence of that scheme are studied. Numerical experiments are carried out. The appropriate graphical illustrations and tables are given.展开更多
A new approach to obtaining space-time conservation schemes is proposed.This approach is very simple and easy to apply in high dimension problems. Numerica1 re-su1ts show that the new schemes obtained by this method n...A new approach to obtaining space-time conservation schemes is proposed.This approach is very simple and easy to apply in high dimension problems. Numerica1 re-su1ts show that the new schemes obtained by this method not only are very efficient andaccurate, but also have very high shock resolution.展开更多
The steady bifurcation flows in a spherical gap (gap ratio =0.18) with rotating inner and stationary outer spheres are simulated numerically for Reci<Re<1500 1500 by solving steady axisymmetric incompressible Na...The steady bifurcation flows in a spherical gap (gap ratio =0.18) with rotating inner and stationary outer spheres are simulated numerically for Reci<Re<1500 1500 by solving steady axisymmetric incompressible Navier-Stokes equations using a finite difference method. The simulation shows that there exist two steady stable flows with 1 or 2 vortices per hemisphere for 775<Re<1220 and three steady stable flows with 0, 1, or 2 vortices for 1 220<Re<l500. The formation of different flows at the same Reynolds number is related with different initial conditions which can be generated by different accelerations of the inner sphere. Generation of asro-or two-vortex flow depends mainly on the acceleration, but that of one-vortex flow also depends on the perturbation breaking the equatorial symmetry. The mechanism of development of a saddle point in the meridional plane at higher Re number and its role in the formation of two-vortex flow are analy2Ed.展开更多
文摘In this paper, a numerical model is established. A modified N-S equation is used as a control equation for the wave field and porous flow area. The control equations are discreted and solved by the finite difference method. The free surface is tracked by the VOF method. The pressure field and velocity field of the whole flow area are solved by the reiterative iteration method. Finally, compared with the physical model test results of wave flume, the numerical model established in the present study is validated.
基金The project supported by the National Natural Science Foundation of China
文摘In this paper, the supersonic chemically reacting mixing layer is simulated with the third order ENN scheme, based on the Navier-Stokes equations, containing transport equations of all species. The numerical results show that the thickness of mixing layer increases gradually along the flow direction, and that the Kelvin-Helmholtz, instabilities may not exist in mixing layer flows.
文摘The multi-dimensional system of nonlinear partial differential equations is considered. In two-dimensional case, this system describes process of vein formation in higher plants. Variable directions finite difference scheme is constructed. The stability and convergence of that scheme are studied. Numerical experiments are carried out. The appropriate graphical illustrations and tables are given.
文摘A new approach to obtaining space-time conservation schemes is proposed.This approach is very simple and easy to apply in high dimension problems. Numerica1 re-su1ts show that the new schemes obtained by this method not only are very efficient andaccurate, but also have very high shock resolution.
基金Project supported by the National Natural Science Foundation of China.
文摘The steady bifurcation flows in a spherical gap (gap ratio =0.18) with rotating inner and stationary outer spheres are simulated numerically for Reci<Re<1500 1500 by solving steady axisymmetric incompressible Navier-Stokes equations using a finite difference method. The simulation shows that there exist two steady stable flows with 1 or 2 vortices per hemisphere for 775<Re<1220 and three steady stable flows with 0, 1, or 2 vortices for 1 220<Re<l500. The formation of different flows at the same Reynolds number is related with different initial conditions which can be generated by different accelerations of the inner sphere. Generation of asro-or two-vortex flow depends mainly on the acceleration, but that of one-vortex flow also depends on the perturbation breaking the equatorial symmetry. The mechanism of development of a saddle point in the meridional plane at higher Re number and its role in the formation of two-vortex flow are analy2Ed.
