A central problem in the mathematical analysis of fluid dynamics is the asymptotic limit of the fluid flow as viscosity goes to zero.This is particularly important when boundaries are present since vorticitv is typica...A central problem in the mathematical analysis of fluid dynamics is the asymptotic limit of the fluid flow as viscosity goes to zero.This is particularly important when boundaries are present since vorticitv is typically generated at the boundary as a result of boundary layer separation.The boundary laver theory,developed by Prandtl about a hundred years ago,has become a standard tool in addressing these questions.Yet at the mathematical level,there is still a lack of fundamental understanding of these questions and the validity of the boundary layer theory.In this article,we review recent progresses on the analysis of Prandtl’s equation and the related issue of the zero-viscosity limit for the solutions of the Navier-Stokes equation.We also discuss some directions where progress is expected in the near future.展开更多
This paper deals with the blow-up properties of solutions to semilinear heat equation ut-uxx= up in (0, 1) × (0, T) with the Neumann boundary condition ux(0, t) = 0, u:x1, t) = 1 on [0, T). The necessary and suff...This paper deals with the blow-up properties of solutions to semilinear heat equation ut-uxx= up in (0, 1) × (0, T) with the Neumann boundary condition ux(0, t) = 0, u:x1, t) = 1 on [0, T). The necessary and sufficient conditions under which all solutions to have a finite time blow-up and the exact blow-up rates are established. It is proved that the blow-up will occur only at the boundary x = 1. The asymptotic behavior near the blow-up time is also studied.展开更多
文摘A central problem in the mathematical analysis of fluid dynamics is the asymptotic limit of the fluid flow as viscosity goes to zero.This is particularly important when boundaries are present since vorticitv is typically generated at the boundary as a result of boundary layer separation.The boundary laver theory,developed by Prandtl about a hundred years ago,has become a standard tool in addressing these questions.Yet at the mathematical level,there is still a lack of fundamental understanding of these questions and the validity of the boundary layer theory.In this article,we review recent progresses on the analysis of Prandtl’s equation and the related issue of the zero-viscosity limit for the solutions of the Navier-Stokes equation.We also discuss some directions where progress is expected in the near future.
文摘This paper deals with the blow-up properties of solutions to semilinear heat equation ut-uxx= up in (0, 1) × (0, T) with the Neumann boundary condition ux(0, t) = 0, u:x1, t) = 1 on [0, T). The necessary and sufficient conditions under which all solutions to have a finite time blow-up and the exact blow-up rates are established. It is proved that the blow-up will occur only at the boundary x = 1. The asymptotic behavior near the blow-up time is also studied.