摘要
对流体在放置斜截椭圆柱式涡流发生器矩形槽道内的流动与传热特性进行大涡模拟,得出流场中速度、温度与压力参数的瞬态变化特性,再现温度场、压力场及诱导旋涡的变化过程,并对流动结构及涡流发生器强化传热的机理进行分析。为验证大涡模拟计算结果的准确性,在相同条件下对未布置涡流发生器的空槽道分别采用湍流模型和大涡模拟进行对比计算,两者的计算结果符合较好。计算结果表明:流场中布置的涡流发生器可以诱导漩涡,而由其所诱导的流向涡对强化传热起主要作用。与相同条件下未布置涡流发生器的情况相比,局部对流换热系数可提高64%～105%,平均对流换热系数则可提高17%～36%;涡流发生器附近位置的对流换热系数提高幅度最大,传热面附近流体的流动状况及流动结构与传热密切相关。
The flow and heat transfer characteristics of rectangle channel with inclined-cut ellipsoidal vortex generator are obtained with large eddy simulation. The instantaneous properties of velocity, temperature and pressure in channel are gained. The variety process of temperature, pressure and inducted vortex are revealed. Meantime, the heat transfer enhancement mechanism of vortex generator and flow structure are discussed. The turbulent model is used for verifying correctness of large eddy simulation in calculation of rectangle channel without vortex generator in the same calculation condition. The calculation result with two methods is consistent. The result of simulation indicates that the vortex can be induced by vortex generator. Furthermore, the stream-wise vortex induced by vortex generator pays more important role in heat transfer enhancement. Compared with the channel without inclined-cut ellipsoidal vortex generator in the same condition, the local heat transfer coefficient is enhanced from 64%-105%, and the average heat transfer coefficient is enhanced from 17%-36%. The enhancement of local heat transfer coefficient is occurred nearby the vortex generator. There is a consanguineous relationship between the fluid flow structure and status in near wall region with the local heat transfer.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2007年第10期55-61,共7页
Journal of Mechanical Engineering
基金
国家自然科学(50476063)。
关键词
大涡模拟
斜截椭圆柱
涡流发生器
强化传热
Large eddy simulation Inclined-cut ellipsoid Vortex generator Heat transfer enhancement
