Numerical study of the air inlet angle influence on the air-side performance of plate-fin heat exchangers

Numerical work is performed to study the effect of air inlet angle on heat transfer coefficient and pressure drop of the plate-fin heat exchangers. Two special air inlet angles which are in the horizontal plane and in the longitudinal plane are simulated on 7 fin channel meshes with different fin parameters. The numerical results show that the different flow fields of the two special air inlet angles cause different effects on heat transfer coefficient and pressure drop. When the air inlet angle is in the horizontal plane, the air inlet angle effect is strongly related with the entrance region flow flied. When the air inlet angle is in the longitudinal plane, the air inlet angle effect is related with the whole fin channel flow field because the vortex size is much larger and comparable to the fin length. The effects of the two angles have different variation laws, which are greatly influenced by fin parameters. Finally, a prediction model is established to calculate the heat transfer coefficient and pressure drop of an arbitrary inlet angle. The comparison of prediction results and simulation results for 5 air inlet angles shows good agreement. The maximum prediction error is within 10%. (C) 2015 Published by Elsevier Ltd.