Effect of an inclined angle on the heat transfer and pressure drop characteristics of a wavy-finned-tube heat exchanger

Experiments were carried out to investigate the heat transfer and pressure-drop characteristics of an inclined wavy-finned-tube heat exchanger. Two types of inclined configurations were examined for various frontal velocities. The heat transfer performance of the test coil was analyzed using the ε-NTU method. For forward-inclined coil, the test results indicate that the air-side heat transfer coefficient (h₀) and the Colburn factor (j) decrease as the inclination angle rises. On the other hand, for the same face velocity, there is no measurable effect on the heat transfer performance for side inclination. However, the air-side pressure drop increases with an increase in the inclination angle for both forward- and side-inclined configurations.