surjan singh

In this paper we have studied the effect of free convection on the heat transfer and flow through variable porous medium which is bounded by two vertical parallel porous plates. In this study it is assume that free stream velocity oscillates with time about a constant mean. Periodic temperature is considered in the moving plate. Effect of different parameters on mean flow velocity, Transient velocity, Concentration profile and transient temperature studied in detail.

In this paper, Wavelet Collocation Method has been used to solve nonlinear fin problem with temperature dependent thermal conductivity and heat transfer coefficient. Thermal conductivity of fin materials varies any type so that we consider thermal conductivity as the general function of temperature. Here we consider three particular cases, where we assume that thermal conductivity is constant, linear and exponential function oftemperature. In each case efficiency of fin is evaluated. The whole analysis is presented in dimensionless form and the effect of variability of fin parameter, exponent and thermal conductivity parameter on temperature distribution and fin efficiency is shown graphically and discussed in detail.