heat transfer; transient free; porous medium adjacent; vertical flat; ratio parameter
The effect of temperature dependent viscosity on the heat transfer rate for a transient free convection in a porous medium adjacent to a vertical flat surface is studied. Solutions are obtained numerically by a suitable similarity transformation. It is shown that time taken to reach steady state is more for cooled wall than for heated wall. Also it is found that decrease in the viscosity ratio parameter increases the heat transfer rate and decreases the temperature.