Evaluation of wall thickness and porosity effects on the conjugate free convection heat transfer rate of hybrid nanofluid inside a square cavity

At present study, effects of wall thickness and porosity on the conjugate free convection heat transfer inside a square cavity have been examined. Continuity, momentum and energy equations for fluid and solid matrix phases are governing equations in present work. Mentioned equations and related boundary conditions have been transformed into their non-dimensional forms. They are solved using finite element method, codes in matlab software and auxiliary functions in comsol software. Results of the computational fluid dynamic code are compared with results of valid prior works. Impressions of Rayleigh and Darcy non- dimensional numbers and the parameters such as interface wall thickness, thermal conductivity ratio (thick wall/ fluid) and interface heat transfer coefficient between hybrid nanofluid and solid matrix phases on the heat transfer rate have been probed in the default ranges. Hence, the results are provided in two separated sections for conjugate free convection heat transfer and porous medium in local thermal non- equilibrium conditions. The obtained results expression that increasing thickness of wall and Darcy number cause heat transfer rate of hybrid nanofluid enhance, Although raising interface heat transfer parameter between hybrid nanofluid and solid matrix of porous medium deteriorates heat transfer value of hybrid nanofluid phase. Also, among mentioned parameters, thermal conductivity ratio parameter (thick wall/ hybrid nanofluid) can vary heat transfer rate of porous medium solid matrix.