New thermal effectiveness data and formulae for some cross-flow arrangements of practical interest

This study provides new effectiveness data and closed form relations for some recently proposed cross-flow heat exchanger flow arrangements of industrial and research interest. The study also covers the so called Z-shape flow arrangement of widespread use in the refrigeration and automobile industries. The closed form relations as well as the effectiveness data are presented in the standard effectiveness – number of transfer units (ɛ-NTU) format. Slight deviations have been observed of the arithmetic mean effectiveness results, proposed by Pongsoi et al. (2011, 2012) [3,4], with respect to those from both closed form relations and data from the HETE program (Navarro and Cabezas-Gómez (2005) [9], Cabezas-Gómez et al. (2007) [10]) for several flow arrangements, with deviations increasing with NTU and C∗. Data provided in the present paper, along with the closed form expressions, could be useful in enhancing the external heat transfer coefficient precision based on the procedure of determining the NTU value from the experimentally obtained thermal effectiveness of the heat exchanger.