Bejan’s heatline and mulitphysics analysis of double diffusive free convection in a doubly stratified non-Darcian porous enclosure with heat generation

Abstract

The current article illustrates the characteristics of the MHD free convective transport phenomenon in the thermal and mass stratified fluid-saturated Darcy-Forchheimer porous square cavity under the action of the cross-diffusion (Soret and Dufour effects) heat generation and chemical reaction effects. To acquire the spatial distribution of thermal fluxes along with directional propagation in chemically reactive and heat generative non-Darcy fluid flow, a newly developed heatline model for multi-force effect following the heat function theory is proposed in this study. In addition to the thermal profile visualization tools, the solutal free convective fluid flow fields are visually demonstrated by the massline contours curves using a novel mass-function model analogous to the heat function methodology. On the other hand, for the numerical solution of the non-dimensional form of the partial differential equations governing the study, the finite element method is applied. Moreover, the non-Darcy fluid flow attributes subjected to the multiple forces are graphically portrayed by the streamlines, isotherms, iso-concentrations, cumulative Nusselt/Sherwood number plots, heatlines, and masslines for the related dimensionless parameter. Here, these visuals delineate the contra-rotating fluid flow transition under both the thermal and concentration stratification forces. Especially, forceful retardation in both the thermal and concentration flux’s movements is noticed when magnetic forces are intensified. An upward geometrical shift of the higher concentration region is seen with increasing chemical reaction parameter.