Journal of King Saud University - Science

6

Authors: Chuo-Jeng Huang

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 nonNewtonian 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.

7

Authors: Naveed Ahmeda, Umar Khana, Sheikh Irfanullah Khana, b, Saima Banoa, Syed Tauseef Mohyud-Din

Squeezing flow of an electrically conducting Casson fluid has been taken into account. The laws of conservations under the similarity transformation suggested by Wang (1976) have been used to extract a highly nonlinear ordinary differential equation governing the magneto hydrodynamic (MHD) flow. Resulting equation has been solved analytically by using the variation of parameters method (VPM). A RK-4 numerical solution has also been sought to examine the validity of analytical results. Both the solutions are found to be in an excellent agreement. Convergence of the solution is also discussed. Flow behavior under the modifying involved physical parameters is also discussed and explained in detail with the graphical aid. It is observed that magnetic field can be used as a control phenomenon in many flows as it normalizes the flow behavior. Also, squeeze number plays an important role in these types of problems and an increase in squeeze number increases the velocity profile.