Numerical analysis of plain fin-and-oval-tube heat exchanger with different inlet angles

In industrial applications, oval tubes are often used instead of round tubes in finned tube heat exchanger for improving the heat transfer performance. In this paper, a periodical numerical method based on FLUENT software is carried out to investigate the heat transfer and pressure drop performances of finand-oval-tube heat exchanger with 5 different inlet angles (30°, 45°, 60°, 75° and 90°). The results show that the overall heat transfer coefficient increases with the decrease of inlet angle. Meanwhile, the pressure drop also increases with the decrease of inlet angle. In addition, the local heat transfer coefficient illustrates the variation of fluid flow between tubes. With the decrease of inlet angle, the average Nusselt number increases by 16.7 %. That is because the fluid is blocked by oval tubes seriously, which also results in the largest increment of the pressure drop by 57.8 %. According to the numerical simulation results, the genetic algorithm is used to find the correlations related the inlet angles. © 2013, AIDIC Servizi S.r.l.