轴向旋转通道内浮升力对湍流影响的直接模拟  

Direct Numerical Simulations on Influences of Buoyancy Forces on Turbulent Flow

作　　者：阳祥[1] 李增耀[1] 陶文铨[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2010年第9期11-15,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金重点资助项目(50636050)

摘　　要：采用直接数值模拟方法对绕截面中心轴旋转的方通道内的充分发展湍流进行了数值模拟,湍流雷诺数和普朗特数分别为400和0.71.为了分析浮升力对流体运动的影响,给出了不同格拉晓芙数Gr下的主流平均速度场、温度场、二次流、湍流强度、雷诺应力等湍流统计量的分布情况,并对旋转效应的稳定与否以及由此对湍流统计量的影响进行了分析.结果表明:旋转效应稳定的区域湍流受到抑制,旋转效应不稳定的区域湍流增强,随Gr的增加旋转效应稳定性变得更加复杂;浮升力对流场和温度场有明显的影响,随Gr的增加影响更加明显.Direct numerical simulations were performed for a fully developed axially rotating turbulent square duct flow with a turbulent Reynolds number of 400and a Prandtl number of 0.71.In order to analyze the influences of buoyancy forces on fluid flow,the ensemble averaged turbulent statistical quantities including velocity field,temperature field,turbulent intensity,and Reynolds stress at different Grashof numbers were presented.The stability or instability properties of rotation and their effects on the statistical quantities were also analyzed.The results show that the centrifugal buoyancy influences the averaged velocity field and temperature field significantly and the influence is more obvious with the increase in Grashof number.The centrifugal buoyancy also affects the fluctuation quantities greatly,and the fluctuation intensity increases in the instable side and decreases in the stable side.

关 键 词：方形通道 湍流 换热 浮升力 直接数值模拟 

分 类 号：TK121[动力工程及工程热物理—工程热物理]