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
Thirupathi Thumma, Mishra, O. Anwar Bég
Abstract
A mathematical modelis presented for entropy generation in transient hydromagnetic flow of an electroconductive \nmagnetic Casson (non-Newtonian) nanofluid over a porous stretching sheet in a permeable medium. The \nCattaneo-Christov heat flux model is employed to simulate non-Fourier (thermal relaxation) effects. A Rosseland \nflux model is implemented to model radiative heat transfer. The Darcy model is employed for the porous media \nbulk drag effect. Momentum slip is also included to simulate non-adherence of the nanofluid at the wall. The \ntransformed, dimensionless governing equations and boundary conditions (featuring velocity slip and convective \ntemperature) characterizing the flow are solved with the Adomian Decomposition Method (ADM). Bejan’s \nentropy minimization generation method is employed. Cu-water and CuO-water nanofluids are considered. \nExtensive visualization of velocity, temperature and entropy generation number profiles is presented for variation \nin magnetic field parameter, unsteadiness parameter, Casson parameter, nanofluid volume fraction, permeability \nparameter, suction/injection parameter, radiative parameter, Biot number, relaxation time parameter, velocity slip \nparameter, Brinkman number (dissipation parameter), temperature ratio and Prandtl number. The evolution of \nskin friction and local Nusselt number (wall heat transfer rate) are also studied. The ADM computations are \nvalidated with simpler models from the literature. The solutions show that with elevation in volume fraction of \nnanoparticle and Brinkman number, the entropy generation magnitudes are increased. An increase in Darcy \nnumber also increases the skin friction and local Nusselt number. Increasing magnetic field, volume fraction, \nunsteadiness, thermal radiation, velocity slip, Casson parameters, Darcy and Biot numbers are all observed to \nboost temperatures. However, temperatures are reduced with increasing non-Fourier (thermal relaxation) \nparameter. Greater flow acceleration is achieved for CuO-water nanofluid compared with Cu-water nanofluid \nalthough the contrary response is computed in temperature distributions. The simulations are relevant to the high \ntemperature manufacturing fluid dynamics of magnetic nanoliquids, smart coating systems etc.