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Water condensate retained inside an automotive evaporator has remained as one of the primary sources of unpleasant “odors”, which in turn can drive up the warranty cost for automotive manufacturers. The “wet” evaporator fin can also underperform due to the presence of condensate blocking the air passage. Moreover, condensate retention can be a potential factor of freezing up evaporators. Thus, an evaporator fin must be designed such that it can shed and drain water condensate as well as provide an excellent heat transfer capability. While the importance of water retention is well known, there seems lacking of a comprehensive way to evaluate the water retention characteristics of a particular product. In this work, attempts were made to answer four questions: (1) What is the mechanism that controls water condensate retention characteristics in an automotive evaporator? (2) Can different water retention evaluation methods reveal the same characteristics?

This paper chronicles a heat exchanger development project that utilized an integrated development process. A combination of full-scale heat exchanger performance testing, flow visualization experiments, and computational fluid dynamics methods were used in concert to investigate flow phenomena in multilouver fins. The primary goal of this project was to confirm the flow and heat transfer enhancement mechanisms at work in multilouver fins. A second goal was correlation of flow visualization, CFD, and traditional full-scale heat exchanger testing. Excellent agreement was found between the three methods.