Effect of porous insertion on convective energy transport in a chamber filled with a temperature-dependent viscosity liquid in the presence of a heat source term

Development of electronic devices demands to create an effective cooling system using optimal working liquid and porous insertions near the heat-generating elements. Such features allow intensifying the heat disposal from the heated element area. In this study, the unsteady convection of a variable viscosity liquid within a chamber having a heat-generating element under the impact of porous insertion is investigated. A porous layer surrounds the energy source located on the lower surface. The horizontal and vertical walls are thermally insulated, kept at constant cooling temperatures, respectively. Partial differential equations written in non-dimensional non-primitive variables with appropriate additional conditions are worked out by the finite difference method. The governing characteristics are the non-dimensional medium permeability, volumetric heat flux, variable viscosity and thickness of the porous insertion. The influence of these properties on local and mean fields' characteristics for the energy transport and flow structures are studied in details. The calculations demonstrate that the inclusion of a porous insertion and the variation of its properties lead to more essential cooling of the heater. (C) 2019 Published by Elsevier Ltd.