Influence of conjugate heat transfer on the minimization of entropy generation for forced convective flow through parallel plate channel filled with porous material

Abstract

A fluid–solid conjugate heat transfer model is developed to analyze the characteristics of entropy generation for forced convective steady hydrodynamically fully developed laminar flow of a Newtonian fluid through a parallel plate channel filled with porous material by modulating the following parameters: substrate thickness, the ratio of thermal conductivity of wall to fluid, Biot number, the axial temperature gradient in the fluid, and Peclet number. The exteriors of both the walls are subjected to the thermal boundary conditions of the third kind. The mass and Brinkman momentum conservation equations in the fluidic domain and the coupled energy conservation in both the solid and fluidic domain are solved analytically using the local thermodynamic equilibrium model, so as to derive closed‐form expressions for the velocity in the fluid and the temperature both in the fluid and solid walls in terms of relevant parameters. Suitable combinations of influencing factors, namely the geometric parameters of the system, fluid, flow, and substrate properties are identified for which global entropy generation rate is minimized. The findings may be helpful in the design of thermal systems frequently used in diverse engineering applications having heat transfer in the solid wall being a crucial parameter.

Analysis of conjugate heat transfer for forced convective flow through wavy minichannel

“…The conjugate heat transfer is governed by the conservation of mass and momentum equations in the fluidic domain and the coupled energy conservation equations in both the fluid and solid domain. By neglecting viscous dissipation and radiation heat transfer effects and assuming constant thermo-physical properties for both the solid and fluid, the governing equations are (Borah and Pati, 2021a, 2021b; Faizan et al , 2022):…”

“…Such proposition may hold true when the conductive resistance in the solid wall is negligibly small either due to higher thermal conductivity of the solid substrate or because of negligible thickness of the wall. Nonetheless, in several applications involving internal forced convective flow, the effect of conduction heat transfer in the solid walls may be extremely decisive in dictating the thermal transport characteristics (Borah and Pati, 2021a, 2021b; Faizan et al , 2021). Accordingly, one should analyze the transport phenomena in the fluidic domain and the conductive heat transfer in the solid substrate simultaneously, which is termed as conjugate heat transfer.…”

Effect of non-uniform heating on conjugate heat transfer performance for nanofluid flow in a converging duct by a two-phase Eulerian–Lagrangian method

“…Borah et al 35 investigated the non-uniform heating on conjugate heat transfer in a duct and concluded that heat transfer rate decreases with the increase in the amplitude of sinusoidal non-uniform heating. Borah and Pati 36 worked on conjugate heat transfer filled with porous medium and found that the thermal conductivity of the solid wall also plays a decisive role for entropy generation. Borah et al 37 investigated the non-uniform asymmetric heating on conjugate heat transfer in a microchannel and concluded that asymmetric heating has more influence than nonuniform heating.…”