Double-diffusive convection in viscous flow over a rotating porous and moving disk

Abstract

This paper presents the double-diffusive convection in the flow of viscous fluid over a heated, rotating, porous and moving disk. All the field quantities, defined at the surface of such disk, are nonuniform and nonlinear, therefore, the boundary conditions of the simulated problem are nonhomogeneous and variable. A set of new variables is found and it has simplified the system of six PDE's along with the boundary conditions into a system of coupled ODE's of boundary value type. The system of nonlinear, coupled and boundary value ODE's has some nine dimensionless parameters, whereas, effects of these numbers have been seen on all field variables, tangential and surface shear stresses and rates of heat and mass transfer. The present simulations have generalized the concept of rotating disk flows in the sense that the three components of velocity, associated with the disk, are taken nonuniform and nonlinear, whereas, the other thermodynamic properties, specified at the surface of the disk, also have the nonlinear nature. In this investigation, we focused on weak and strong assisting and opposing flows of liquids and gases over a rotating disk in the presence of stretching, shrinking, injection and suction velocities. Each component of velocity is effectively (slightly) enhanced with the variation of and in case of assisting (opposing) flow in the presence of stretching/shrinking and injection/suction. Moreover, similar behavior of the other field variables and quantities of physical interests has been noticed. Thin momentum, thermal and concentration boundary layers are appeared in some cases, which are clearly demonstrated in graphs in special situations.