Evaluation of turbulence models for simulating flow and heat transfer in cross-corrugated triangular channels

A novel exchanger structure, i.e., cross-corrugated triangular ducts has been proposed recently to provide high heat transfer capabilities in air-to-air heat exchangers. The efficiency improvement is attributed to the pattern of flow that undergoes abrupt turnaround, contraction and expansion. The heat transfer characteristics and friction performance in this complex geometry are of great importance for system design. In this study, periodic fully developed fluid flow and heat transfer inside such structure under uniform wall temperature condition are numerically investigated. For the purpose of model performance evaluation, seven turbulence models, i.e., Ske, RLZ, RNG, sstkw, Trans-sst, k-kl-w and RSM, are employed to study the hydrodynamic characteristics of this channel. The segment mean Nusselt numbers (Nu) and friction factors (f) are presented and compared with the available correlations and experimental data. The results show that the best predictions are provided by RSM model and thus it is highly recommended for application. The differences between simulated and experimental Nu values are within 7%.