几何参数对涡发生器流动传热特性影响研究

Study of Heat Transfer and Flow Friction Characteristics of Vortex Generator with Various Geometrical Parameters

本文首先对"common flow down"(A形式)和"common flow up"(B形式)两种形式纵向涡发生器的流动换热性能进行了计算比较,发现B形式纵向涡发生器Nu数比A形式纵向涡发生器在计算范围内平均增大2.8%,而f因子却平均减少9.1%,这表明B形式纵向涡发生器是一种性能更加优异的强化传热表面方式;考察了B形式纵向涡发生器的几何参数对流动换热性能的影响,结果表明B形式纵向涡发生器空气侧Nu数与f因子随着攻角减小、高度h_(VG)增大、x_(VG)减小、y_(VG)减小而增大,而随着长度l_(VG)的增大Nu数先增大后减小,同样f因子随着长度l_(VG)的增大也先增大后减小。

In this study,the effects of various vortex-generator configurations on the heat transfer and flow friction characteristics are investigated by numerical method.Compared with 'common flow down' configuration,the average Nu numbers of 'common flow up' configuration increase by 2.8%in the range of studied Reynolds number,while the average /-factors reduce by 9.1%.A comparative study of the effects of location of axial dimension,location of spanwise dimension,attack angle,length and height of vortex generator on fin performance is conducted.The results show that the intensity of heat transfer can be greatly increased with decreasing vortex generator location and attack angle,and with increasing vortex generator height,accompanying with the increase of pressure drop.The Nu number and /-factor firstly increase and then decrease with increasing length of vortex generator.