Semiporous Media Approach for Numerical Simulation of Flow through Large-Scale Sparse Tubular Heat Exchangers

Steady-state, three-dimensional numerical simulations for airflow through large-scale sparse tubular heat exchangers are performed using Fluent (2006). A new porous media approach, semiporous media, is developed to simplify, the computational fluid dynamics (CFD) modeling. In this approach, the tube bundle is simplified to a porous media zone that has half real tubes on both sides of it. Three CFD approaches, the real tube one, the semiporous media one, and the conventional porous media one, are compared in the predictions of the tubular heat exchanger airflow distributions. The comparison shows that the semiporous media approach predicts airflow distribution similar to the real tube distributions, reduces computational cost significantly, and can be easily implemented. The heat exchanger pressure drops predicted by the semiporous media approach are compared with the experimental data for eight designs. The results show that this new approach gives reasonable agreement with the experiments.