Scaling of heat transfer coefficients along louvered fins

Louvered fins provide a method for improving the heat transfer performance of compact heat exchangers without a prohibitive increase in the pressure drop. Spatially resolved heat transfer coefficients along the louvers protruding from the fins are needed to understand the details of compact heat exchanger performance. Experiments were conducted in a number of large-scale louver models with varied fin pitch and louver angle over a range of Reynolds numbers. This paper presents a method for evaluating the spatially resolved louver heat transfer coefficients using various reference temperatures, such as the bulk flow temperature and adiabatic wall temperature, to define the convective heat transfer coefficients. The results from this study indicate that the thermal field surrounding a particular louver is the overriding influence on the heat transfer from that louver.