Natural convection in a rectangular cavity washed externally by a turbulent boundary layer

Abstract

A convection-to-convection conjugate heat transfer problem is investigated numerically by using finite difference methods. Heat transfer through a recirculating buoyant Navier-Stokes flow in a rectangular cavity, heated from below and washed externally on the top by a turbulent boundary layer, is considered. Difficulty here lies in the fact the two different convection modes are coupled by an unknown thermal condition along the thin horizontal partition between the two flows. Numerical analysis is performed to find the parametric effect of Reynolds number, Grashof number and the geometrical aspect ratio of the cavity. It is found that depending upon the strength of the external flow, patterns of natural convection in the cavity can be changed. The rotating direction of the inner buoyant cells is dictated by the existence of the external flow, and the cellularity of the cavity flow is increased by its strength.