Alexandria Engineering Journal (Apr 2023)
Numerical passive control of alumina nanoparticles in purely aquatic medium featuring EMHD driven non-Darcian nanofluid flow over convective Riga surface
Abstract
Motivated by the thermal importance of feeble electrically conducting nanofluids and their flow controls in many industrial and engineering applications, the present scrutinization intended to evidence comprehensively the main electro-magneto-hydrothermal and mass aspects of convective non-homogeneous flows of alumina-based pure water nanofluids Al2O3-H2O over a horizontal flat surface of an electromagnetic actuator (i.e., Riga pattern, which is embedded geometrically in a Darcy-Forchheimer porous medium. Further, the present nanofluid flow model is formulated realistically under the umbrella of the renovated two-phase Buongiorno’s approach with the inclusion of Brownian motion and thermophoresis diffusive phenomena, in which the vertical component of the nanoparticles’ mass flux tend to vanish at the limiting contact surface due to its impermeability trend. For streamlining the technical handling of the present nanofluid flow problem, the governing partial differential equations (PDEs) are simplified mathematically by adopting the physical approximations of the boundary layer theory and then transformed into a differential structure of ordinary differential equations (ODEs) based on several similarity changes. Methodologically, the resulting nonlinear coupled ODEs are solved numerically via a validated differential quadrature procedure. Besides, the generated graphical demonstrations show that the nanofluid temperature is enhanced significantly with the porosity factors, the nanoparticles’ loading, the convective heating strength, and the thermophoresis process. However, the porosity factors and the nanoparticles’ loading exhibit a slowing-down impact on the nanofluid motion. Usefully, it is revealed from the obtained GDQM - NRT datasets that the nanoparticles’ loading and the porosity factors express an important improvement in the strength of the surface viscous drag forces, whereas the induced electromagnetic field shows a reverse viscous frictional impact.
