The unsteady mixed-convection boundary layer induced by a vortex

摘要

The unsteady evolution of a boundary layer induced by a two-dimensional vortex convecting above a heated surface is considered numerically. This model problem is representative of the types of interactions which can occur when vortices encounter solid surfaces in a wide variety of diverse applications involving high-Reynolds number and/or high-Grashof number flows. It is known that in the case without heat transfer, the vortex-induced boundary layer evolves toward a singularity as it forms a sharp spike which erupts away from the surface. Numerical solutions of the unsteady mixed-convection boundary-layer equations in the Boussinesq limit are obtained in Lagrangian coordinates, which have clear advantages over calculations based on the conventional Eulerian approach. Solutions for various values of the inclination angle of the surface and Grashor number show that the coupling between the fluid flow and heat transfer can have a dramatic effect upon the transport of momentum and energy within the boundary layer in the presence of a vortex.