Arrhenius kinetics driven nonlinear mixed convection flow of Casson liquid over a stretching surface in a Darcian porous medium.

The non-linear mixed convective heat and mass transfer features of a non-Newtonian Casson liquid flow over a stretching surface are investigated numerically. The stretching surface is embedded in a Darcian porous medium with heat generation/absorption impacts. The fluid flow is assumed to be driven by both buoyancy and Arrhenius kinetics. The governing equations are modelled with the help of Boussinesq and Rosseland approximations. The similarity solutions of the non-dimensional equations are obtained using two numerical approaches, namely fourth fifth Runge - Kutta Fehlberg method and the shooting approach. The velocity, temperature and concentration profiles are discussed for important physical parameters through various graphical illustrations. The skin friction, the non-dimensional wall temperature, and the concentration expressions were derived and analysed. The results indicate that the increasing values of linear and nonlinear convection due to temperature, nonlinear convection due to concentration, and heat of reaction increase the dimensionless wall temperature. The dimensionless wall concentration rises with the increasing values of heat of reaction, linear and nonlinear convection due to temperature, and nonlinear convection due to concentration parameters.

Numerical study of heat generating γ Al 2 O 3 - H 2 O nanofluid inside a square cavity with multiple obstacles of different shapes.

A numerical research on uniformly heat generating γ Al 2 O 3 -H 2 O nanofluid filled square cavity with multiple obstacles of different shapes is carried out. The cavity is assumed to be heated at bottom and cooled by vertical walls with linearly varying temperature. An adiabatic condition is assumed at the top of the cavity. Circular, square and triangular shaped obstacles are considered. The mathematical model has been solved using Galerkin finite element method. Results are presented for streamlines, isotherms, local and mean Nusselt numbers. Multiple rotating cells are observed in the streamlines. It is found that the local and mean Nusselt numbers increase with nanoparticle volume fraction and higher heat transfer is achieved in the cavity with triangular obstacles.

Riga - Plate flow of γ Al2O3-water/ethylene glycol with effective Prandtl number impacts.

In many industrial processes, the cooling process can be improved by varying the flow geometry or changing the additives in the working fluid. The present work concentrates on the flow of γ Al2O3 -Water/Ethylene Glycol over a Gailitis and Lielausis device with an effective Prandtl number for the first time. The thermal transport aspects of electro-MHD boundary layer flow of γ Al2O3 nanofluids over a stretchable Riga plate are studied in two dimensions. The wall parallel Lorentz force is produced due to an external electric field by Riga plate to control the nanofluid flow. Mathematical models are developed with an effective Prandtl number. The no-slip and the prescribed surface temperature boundary conditions are assumed. Results are discussed using numerical results obtained by fourth order RK method with shooting technique. Special case analytical solutions are presented for both momentum and energy equations. The increasing behaviour in velocity profile and decreasing behaviours in temperature, skin friction and Nusselt number are observed with increasing modified Hartmann number. The higher modified Hartmann number leads to a sudden enhancement in the velocity profile of the nanofluid in the presence of effective Pr near the riga plate wall.