Abstract

The aim of the present study is to numerically investigate the thermal performance of a heat exchanger tube fitted with vortex generator inserts. In the present paper, three configurations of vortex generators—straight, double-curved, and triple-curved—are proposed to achieve the optimum configuration design that provides the highest thermal performance. The thermal performance results of the tubes fitted with the proposed vortex generators are compared with those fitted with a classical twisted tape and a plain tube. The triple-curved vortex generator, which is tested at four different pitch ratios (5, 4, 3, and 2), exhibits the highest thermal performance at a low Reynolds number. The numerical results indicate that the thermal performance increases as the pitch ratio decreases. Compared with the twisted tape, if the triple-curved vortex generator is employed at a pitch ratio of 2, the thermal performance can improve by approximately 24%. Using the numerical results of the current study, dimensionless correlations for the triple-curved vortex generator are developed and presented in this paper.

摘要

本研究的目的是对装有涡流发生器插件的换热器管的热性能进行数值研究。在本文中，提出了三种涡流发生器配置——直线型、双曲线型和三曲线型——以实现提供最高热性能的最佳配置设计。将装有建议涡流发生器的管的热性能结果与装有经典双绞带和普通管的管的热性能结果进行比较。三曲线涡流发生器在四种不同的螺距比（5、4、3 和 2）下进行测试，在低雷诺数下表现出最高的热性能。数值结果表明，热性能随着螺距比的减小而增加。与扭纹胶带相比，如果采用螺距比为2的三弯涡流发生器，热性能可提高约24%。使用当前研究的数值结果，本文开发并介绍了三曲线涡流发生器的无量纲相关性。