Irreversibility analysis in time-dependent Darcy–Forchheimer flow of viscous fluid with diffusion-thermo and thermo-diffusion effects

Abstract

In this article, we analyze the entropy analysis in unsteady hydromagnetic flow of a viscous fluid over a stretching surface. The energy attribute is scrutinized through dissipation, heat source/sink, and radiation. Furthermore, diffusion-thermo and thermo-diffusion behaviors are analyzed. The physical description of the entropy rate is discussed through the second law of thermodynamics. Additionally, a binary chemical reaction is considered. Partial differential equations are transformed into ordinary ones by adequate variables. Here, we used an optimal homotopy analysis method (OHAM) to develop a convergent solution. The influence of flow variables on velocity, Bejan number, thermal field, concentration, and entropy rate is examined through graphs. The physical performance of drag force, Sherwood number, and temperature gradient versus influential variables is studied. A similar effect holds for velocity through variation of porosity and magnetic variables. An increment in thermal field and entropy rate is noted through radiation. A reverse trend holds for the Bejan number and thermal field through a magnetic variable. An augmentation in the Soret number enhances the concentration. An amplification in drag force is noted through the Forchheimer number. Higher estimation of radiation corresponds to a rise in the heat transfer rate.

Keywords

• darcy–forchheimer model
• entropy generation
• viscous dissipation
• heat source/sink
• chemical reaction
• thermal radiation and soret and dufour effects