Thermal radiation effect of mixed convection of couple stress fluid in a vertical channel in the presence of heat source or heat sink

Abstract

The fully developed mixed convection of couple stress fluid in a vertical channel in the presence of heat source or sink and thermal radiation effect is analyzed. The two boundaries of the channel are considered as isothermal-isothermal, isoflux-isothermal and isothermal-isoflux for the left and right walls and kept either at equal or at different temperature. The governing momentum and energy equations are coupled and nonlinear due to the viscous effects. The results are represented graphically for different values of buoyancy parameter , couple stress parameter 'a' and radiation parameter F on velocity and temperature distributions. We observe that for purely viscous fluid with the flow reversal was at the hot wall whereas for couple stress fluid there is a flow reversal both at left and right walls. The effect of on the flow for couple stress fluid is dominating compared to viscous fluid both on velocity and temperature. The profiles of temperature are significant for couple stress fluid for different values of whereas the profiles were not sensible for different values of for viscous fluid.