Effects of heat source/sink on Darcy–Bènard triple-diffusive convection in a porous-fluid system

In the presence of a constant heat source/sink in both layers of the porous–fluid system, the Darcy–Bènard Triple-Diffusive Convection (DBTDC) problem is investigated for two types of Thermal Boundary Combinations (TBCs). For type (i) adiabatic–adiabatic and type (ii) adiabatic–isothermal TBCs, the system of ordinary differential equations derived from normal mode analysis is solved in closed form for the eigenvalue, Thermal Marangoni Number (TMN). The depth ratio thoroughly explains the influence of several parameters on the eigenvalue, hence on DBTDMC. It is noticed that the parameters in the study have a larger influence on the porous layer dominant composite layer systems than that on the fluid layer dominant composite systems.