Modelling laminar transport phenomena in a Casson rheological fluid from an isothermal sphere with partial slip in a non-Darcy porous medium

Abstract

The flow and heat transfer of Casson fluid from a permeable isothermal sphere in the presence of slip condition in a non-Darcy porous medium is analyzed. The sphere surface is maintained at a constant temperature. The boundary layer conservation equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite-difference scheme. Increasing the velocity slip parameter is found to decrease the velocity and boundary layer thickness and increases the temperature and the boundary layer thickness. The velocity decreases with the increase the non-Darcy parameter and is found to increase the temperature. The velocity increases with the increase the Casson fluid parameter and is found to decrease the temperature. The Skin-friction coefficient and the local Nusselt number is found to decrease with the increase in velocity and thermal slip parameters respectively.

Keywords

• non-Newtonian fluid mechanics
• Casson model
• yield stress
• slip condition
• Keller-Box numerical method
• heat transfer
• skin friction
• Nusselt number
• boundary layers
• isothermal sphere