Entropy generation on the variable magnetic field and magnetohydrodynamic stagnation point flow of Eyring–Powell hybrid dusty nanofluid: Solar thermal application

Abstract

The prime intention of this study is to analyse the significance of the variable magnetic field and magnetohydrodynamic stagnation point flow of Eyring–Powell hybrid dusty nanofluid over a Darcy–Forchheimer sheet. The hybrid nanofluid was formulated by suspending the nanoparticles of copper (Cu) and zirconium dioxide (ZrO₂) into a base fluid mixture of (C₂H₆O₂) ethylene glycol (50%) + (H₂O) water (50%). The mixture of two different base fluid properties has notable results compared to using a single base fluid. Because when we used the mixture of both base fluids, we obtained better heat conductivity than pure ethylene glycol and a lower freezing point than water. Glycol water has several applications in solar heating installation and antifreeze in automobiles. The suitable self-similarity transformations are employed to convert the hybrid and dusty nanofluids transport equations into ordinary differential equations and then resolved using the Runge–Kutta fourth order with the shooting method in the MATLAB solver. The calculated results are plotted graphically through velocity, temperature, entropy generation, local skin friction coefficient and rate of heat transfer. The velocity profile enhances with the higher values of the Eyring–Powell fluid parameter. Entropy generation (N _G ) and Bejan number (Be) have an opposite nature on the Brinkman number (Br). The rate of heat transfer rises for the higher values of the radiation parameter and opposite behaviour is observed to the magnetic field parameter. It is noticed that hybrid nanofluids have a higher heat transfer process than dusty nanofluids.