ADM Solution for Cu/CuO –Water Viscoplastic Nanofluid ‎Transient Slip Flow from a Porous Stretching Sheet with Entropy ‎Generation, Convective Wall Temperature and Radiative Effects

A mathematical model is presented for entropy generation in transient hydromagnetic flow of an electroconductive magnetic Casson (non-Newtonian) nanofluid over a porous stretching sheet in a porous medium. The model employed is Cattaneo-Christov heat flux to simulate non-Fourier (thermal relaxation) effects. A Rosseland flux model is implemented to model radiative heat transfer. The Darcy model is employed for the porous media bulk drag effect. Momentum slip is also included to simulate non-adherence of the nanofluid at the wall. The transformed, dimensionless governing equations and boundary conditions (featuring velocity slip and convective temperature) characterizing the flow are solved with the Adomian Decomposition Method (ADM). Bejan’s entropy minimization generation method is employed. Cu-water and CuO-water nanofluids are considered. Extensive visualization of velocity, temperature, and entropy generation number profiles is presented for variation in pertinent parameters. The calculation of skin friction and local Nusselt number are also studied. The ADM computations are validated with simpler models from the literature. The solutions show that with elevation in the volume fraction of nanoparticle and Brinkman number, the entropy generation magnitudes are increased. An increase in Darcy number also upsurges the friction factor and heat transfer at the wall. Increasing volume fraction, unsteadiness, thermal radiation, velocity slip, Casson parameters, Darcy, and Biot numbers are all observed to boost temperatures. However, temperatures are reduced with increasing non-Fourier (thermal relaxation) parameter. The simulations are relevant to the high temperature manufacturing fluid dynamics of magnetic nano liquids, smart coating systems.

Keywords:

Cattaneo-Christov (Non-Fourier) Heat Flux Model , Casson Nanofluid , Adomian Decomposition Method , Convective and Slip ‎Conditions , Porous media , Magnetohydrodynamic Materials Processing