Effects of suction/injection on unsteady reactive variable viscosity non-Newtonian fluid flow in a channel filled with porous medium and convective boundary conditions

A study on thermal effects of the suction/injection Reynolds number, in conjunction with other flow parameters, on an unsteady reactive temperature dependent viscosity third grade fluid in a porous channel filled with saturated porous medium is presented. It is assumed that the channel walls are subjected to asymmetric convective heat exchange with the surrounding medium and that exothermic chemical reactions take place within the flow system. The heat exchange with the ambient at the surfaces is assumed to obey Newtonʹs law of cooling. The equations governing the flow system are expressed in non-dimensional form and a semi-implicit finite difference scheme is utilised to obtain the velocity and temperature profiles. The effects of the flow parameters on the temperature and velocity fields, the skin friction and the wall heat transfer rate are simulated and discussed. The suction/injection Reynolds number is observed to retard the velocity field. It is also observed that the suction/injection Reynolds number, the porous medium parameter, the Prandtl number and the Biot number have a retarding effect on the temperature field. The variable viscosity parameter and the suction injection Reynolds number increases the skin friction while the porous medium parameter and the Prandtl number diminish it. It is also revealed that the suction injection Reynolds number, the porous medium parameter and the Prandtl number have a diminishing effect on the rate of heat transfer at the channel walls.