Convective Heat Transfer in Casson Fluid Flow over a Porous Stretching Surface with Slip Conditions and Thermal Radiation

Abstract

The current research provides an extensive analysis of the convective heat transfer in Casson fluid flowing over a porous stretching surface with the consideration of velocity slip and thermal radiation effect. In addition, the Casson fluid model is a class of non-newtonian fluids with yield-stress behavior which has application to various material (such as blood and polymer suspension) as described earlier. The governing PDE's were developed from the basic Navier-Stokes equation by including velocity-slip, surface suction/injection and radiative heat transfer models. Using similarity transformation, the original PDE's were reduced to a system of two coupled nonlinear ODE's. A fourth order Runge-Kutta solution was obtained for each of these ODE's with a shooting technique used to obtain accurate boundary-value solutions. The results provide details of how the Casson parameter, slip-coefficient, radiation-intensity and permeability affect both the local velocity and temperature profiles. Key-performance parameters (i.e., skin-friction coefficient and nusselt-number) were also investigated in detail. It was found that increasing values of the Casson parameter increase the velocity of the fluid and decrease the effects of the yield-stress. Increasing slip at the surface and/or increasing the thermal-radiation will cause the thermal-boundary-layer to grow, thus modify the heat-transfer-rate. The results presented in this study can be useful in optimizing heat and mass transfer in various industrial and biomedical applications in which the complex fluid behaviors are involved.