Optimal design of an array of porous obstacles in a partially heated channel using lattice Boltzmann method for the heat transfer enhancement

Abstract

The present work investigates the heat transfer enhancement in a channel includes a number of porous obstacles. A partially heated channel is considered, and an array of porous blocks installed on the channel wall is used as an effective heat transfer enhancement mechanism. The flow and temperature fields are resolved using a well-tuned lattice Boltzmann method. An optimal design is obtained for the porous obstacles considering the blocks' height and pitch together with the permeability of the porous medium as the design parameters. In addition, the impact of Da on the thermal performance of the porous block is studied. The PEC number (Performance Evaluation Criteria), which simultaneously accounts for the pressure drop penalty and the heat transfer rate augmentation, is chosen as a proper thermal performance evaluation criteria. The obtained results show an optimum value for both blocks' height and pitch, which depends on the Da. Moreover, the impact of obstacle geometry and the distribution of porous material inside the channel is investigated on the thermal performance of the heat-removing system.