Investigating the impacts of included angles on flow and heat transfer in cross-corrugated triangular ducts with field synergy principle

Included angles (α) have vital effect on the flow and heat transfer in cross-corrugated triangular ducts. The friction factor and Nusselt number were estimated at different Reynolds numbers from both experiments and simulations. Results show that the flow in the duck with α=90 has the largest friction factor and Nusselt number. However, the included angle influences the flow and heat transfer in cross-corrugated triangular ducts in different ways. The field synergy principle was used to explore the mechanism of the different impacts of the included angle. Results show that the flow in the cross-corrugated triangular duct with α=90o has the smallest domain averaged included angle (βm), which implies the best synergy performance. The results of the field synergy principle were also validated by analyzing the performance evaluation criterion and studying the velocity vector and temperature distributions