Numerical modeling of thermophoresis and Brownian with heat transfer in shear-rate-dependent fluid: The finite element simulations

Abstract

This article discusses the simultaneous influence of thermophoresis, Brownian motion, and the dispersion of nanoparticles on thermal enhancement in non-Newtonian fluid existing over a surface stretching with non-uniform velocity. The modeled problems describing the transport of heat by the fluid are boundary value problems and are solved by the finite element method (FEM). The mesh-free analysis is done and accuracy is checked. The numerical solutions are computed and used for depicting flow field behaviors. It is visualized that Cu− Prandtl fluid and Cu−Al2O3− Prandtl fluid flow are affected in opposing ways by Prandtl and elastic factors. As a result, momentum in the Newtonian fluid does not penetrate as quickly as that does in Prandtl fluid. The Brownian motion parameter is responsible for a decrease in the Nusselt number whereas the thermophoresis parameter causes a decrease in the Sherwood number. Thus, it is essential to note that the wall heat transfer rate in the fluid can be enhanced by making arrangements to reduce Brownian motion. Similarly, wall mass flux can be controlled through the thermophoresis parameter. Nusselt and Sherwood number has shown an increasing tendency when the Prandtl parameter is increased. Thus, fluids with higher Prandtl fluid parameters are suitable for higher wall heat and mass fluxes. The temperature of mono and hybrid nano-Prandtl fluids is increased by caused by thermophoresis and Brownian motion.

Keywords

• Non-Newtonian fluid
• Numerical modeling
• Thermal efficiency
• Numerical simulation
• Nanoscales particles
• Nusselt number