Abstract
Heat transfer inside wall-joint-fins systems is analyzed. The coupled two-dimensional energy equations of the wall and the joint-fin are solved numerically using an iterative high order scheme finite volume method. Advanced fine analytical solution is proposed and various closed form equations for different heat transfer augmentation indicators are obtained. Excellent agreement is noticed between the numerical and the analytical results. Wall-joint-fins systems are more effective in transferring thermal energy when the joint-fin is made of a highly conductive material. Moreover, varying the joint-fin lengths ratio may increase the system effectiveness by a factor of 1.2. In addition, the maximum reported system effectiveness is 925% above that when both wall and joint-fin have same thermal conductivity. The maximum system effectiveness which occurs at specific geometrical aspect factors increases as convective heat transfer coefficients increase. Furthermore, the effectiveness and efficiency of the wall-joint-fins system increase as the relative joint-fins to wall volume ratio increases. The wall-joint-fins efficiency is least affected by the joint-fin lengths ratio. Eventually, the heat transfer coefficient between the joint-fin and the wall is identified. Finally, wall-joint-fin systems are recommended as heat transfer enhancing elements.