Efficiency Determination of Radiators with Temperature-Dependent Thermal Conductivity Using Two He's Methods

Variational iteration method (VIM) and homotopy perturbation method (HPM) have been used to evaluate the efficiency of pipe/fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the pipe/fin. These methods are useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. VIM and HPM provide an approximate analytical solution in the form of an infinite power series. The pipe/fin efficiency of the radiators with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity.