Minimization of Rate of Heat Transfer from Rectangular Cavities with Free Convection in Various Aspect Ratios for Finding Characteristics of an Array of Adiabatic Thin Fins by PSO Algorithm

In the present paper, the calculation of the optimum characteristics of thin fins attached to the hot wall in closed cavities with different aspect ratios has been investigated. Free convection is predominant in the cavity. The equations of continuity, momentum, and energy are discretized by means of finite volume method and the equations will be solved by a SIMPLER algorithm. The fins are connected to the hot wall and Particle Swarm algorithm is used to optimize the location and the length of fins. In order to model fins with high heat transfer, the dimensionless diffusion coefficients of momentum and energy equations are set equal to infinity and for the modeling of insulator fins, these coefficients are considered infinite and very small, respectively. The aim is to find the optimum characteristics of the array of fins attached to the hot wall in the rectangular cavities in such a way that the heat transfer from the cold wall is minimized. The results of particle swarm optimization algorithm are compared with the reference amounts. Results show that the particle swarm optimization algorithm is capable to find the optimum characteristics of an array of fins that is not calculated by the other methods, until now. The obtained results showed that with the increase of aspect ratio, the increase of the number of fins (increase in the number of variables), the particle swarm optimization algorithm might not have the needed ability to find the general optimum. This issue was studied by some numerical tests. Therefore, it was concluded that by decreasing the number of variables (Fixed location) and finding only the length of each fin, and also by increasing the number of particles in the sample space, the accuracy of the algorithm can be increased.