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
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.
