Numerical study and experimental verification of transverse direction type serrated fins and field synergy principle analysis

The heat transfer and pressure drop characteristics of transverse direction (TD) type aluminum serrated fins in compact heat exchanger were studied experimentally and numerically in this paper. Firstly, taken lubricant as working fluid and water as coolant, performance tests were carried out for different flow rates in oil side. Variation in the Colburn factor j and the friction factor f relative to Re were examined. Next to that, the effects of structural parameters on thermal characteristics of TD type serrated fins were analyzed numerically. Through comparison of experimental and simulated results, the tendencies agree well. Finally, the heat transfer enhancement mechanism for TD type serrated fins was discussed by field synergy principle (FSP) theory. It is found that vortexes generated near the TD fin region enhanced the turbulence intensity to reduce the thickness of boundary and improve the synergy between the velocity and temperature gradient.