A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently so...A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently solved by the modified incomplete LU decomposition conjugate gradient scheme ( MILU-CG). The effects of surface suction or blowing' s position and strength on the vortex structures in the cylinder wake, as well as on the drag and lift forces at Reynoldes number Re = 100 were investigated numerically. The results show that the suction on the shoulder of the cylinder or the blowing on the rear of the cylinder can effeciently suppress the asymmetry of the vortex wake in the transverse direction and greatly reduce the lift force; the suction on the shoulder of the cylinder, when its strength is properly chosen, can reduce the drag force significantly, too.展开更多
The incompressible Navier Stokes equations are solved via variables of vorticity and velocity. Firstly, a rigorous variational framework with the equivalence between the velocity pressure and the vorticity velocity fo...The incompressible Navier Stokes equations are solved via variables of vorticity and velocity. Firstly, a rigorous variational framework with the equivalence between the velocity pressure and the vorticity velocity formulations is presented in a Lipschitz domain. Next, a class of Galerkin finite element approximations of the corresponding variational form is introduced, and a convergence analysis is given for the Stokes problem. Finally, an iterative finite element solver for the Navier Stokes problem is proposed.展开更多
基金Foundation item:the Natural Science Foundation of Jiangsu Province(BK97056109)
文摘A vorticity-velocity method was used to study the incompressible viscous fluid flow around a circular cylinder with surface suction or blowing. The resulted high order implicit difference equations were effeciently solved by the modified incomplete LU decomposition conjugate gradient scheme ( MILU-CG). The effects of surface suction or blowing' s position and strength on the vortex structures in the cylinder wake, as well as on the drag and lift forces at Reynoldes number Re = 100 were investigated numerically. The results show that the suction on the shoulder of the cylinder or the blowing on the rear of the cylinder can effeciently suppress the asymmetry of the vortex wake in the transverse direction and greatly reduce the lift force; the suction on the shoulder of the cylinder, when its strength is properly chosen, can reduce the drag force significantly, too.
文摘The incompressible Navier Stokes equations are solved via variables of vorticity and velocity. Firstly, a rigorous variational framework with the equivalence between the velocity pressure and the vorticity velocity formulations is presented in a Lipschitz domain. Next, a class of Galerkin finite element approximations of the corresponding variational form is introduced, and a convergence analysis is given for the Stokes problem. Finally, an iterative finite element solver for the Navier Stokes problem is proposed.
