Abstract
Here irreversibility analysis in unsteady Darcy-Forchheimer flow of viscous fluid by a stretched sheet is examined. Lorentz force effect is considered. Energy attribution is discussed through thermodynamic first law with Joule heating, radiation and dissipation effects. Entropy generation is calculated. Thermo diffusion and diffusion-thermo characteristics are also examined. Furthermore binary chemical reaction is addressed. Significance of entropy generation and heat transfer rate is considered. Here our main aim is to discuss the entropy rate and heat transfer analysis. The recommended model is pertinent for heat exchangers, entropy optimization, biomedicine, two-phase flows, polymers, thermal and solutal transportation, fuel cells and geothermal energy system.
Partial differential equations (PDEs) are altered into dimensionless form through appropriate variables. The resulting governing equations are then solved numerically by using finite difference method (FDM).
Influence of sundry variables on velocity, temperature, entropy optimization and concentration are deliberated. Skin friction coefficient and Sherwood and Nusselt numbers are scrutinized. An improvement in velocity field is noticed for Reynold number. An increment in magnetic parameter has reverse trend for temperature and velocity. Temperature is augmented against higher radiation and Dufour number. Concentration has opposite characteristics with variation of reaction parameter and Soret number.
Significance enhancement in velocity gradient is seen for higher magnetic and porosity variables. An increment in Forchheimer number improves the surface drag force. Magnitude of Nusselt number (heat transfer rate) reduces for higher Reynold number. An improvement in radiation declines the heat transfer rate. An augmentation in radiation parameter improves the temperature and entropy generation rate. Entropy generation rate is augmented versus Reynold number and radiation parameter. Entropy optimization and surface drag force have similar effects for magnetic parameter.