Forced convective heat transfer for a self sustained oscillatory flow in a converging-diverging channel.

摘要

A numerical simulation allows us to obtain the unsteady temperature field in a converging diverging two dimensional channel for a laminar self sustained oscillatory flow. Beyond a critical Reynolds number, a linear stability analysis shows that the hydrodynamic perturbation leading to the unsteadiness is triggered by Tollmien Schlichting waves. For a constant heat flux density at the wall we sow that the effect of a small perturbation amplitude leads to a quasi uniform augmentation of the bulk temperature, whereas there is a local diminution of the wall temperature, particularly around the reattachment point for the boundary layer. Correlatively, we observe an augmentation of the local convective heat transfer in this particular zone. This effect increases proportionally witht he Prandtl number.