Effects of internal heat generation and Soret/Dufour on natural convection of non-Newtonian fluids over a vertical permeable cone in a porous medium

Abstract

This investigation examines numerically the combined heat and mass transfer of a uniform blowing/suction, non-Newtonian power-law fluid, and the effects of internal heat generation on natural convection adjacent to a vertical cone in a porous medium in the presence of Soret/Dufour effects. The surface of the vertical cone has a uniform wall temperature and a uniform wall concentration (UWT/UWC). A non-similarity analysis is carried out, and the transformed governing equations are solved using the Keller box method. The effects of the Dufour parameter, the Soret parameter, the Lewis number, the buoyancy ratio, the power-law index of the non-Newtonian fluid, the blowing/suction parameter and the internal heat generation coefficient on the heat and mass transfer characteristics were elucidated. In general, for the case of blowing, both the local Nusselt number and the local Sherwood number decrease. This trend reversed for suction of fluid. The local Nusselt (Sherwood) number decreases (increases) as the internal heat generation coefficient A∗ is increased. Increasing the non-Newtonian fluid n reduces both the local Nusselt number and the local Sherwood number. The physical aspects of the problem are discussed in detail.