近壁湍流脉动的概率分布函数  

Probability Distribution Function of Near-Wall Turbulent Velocity Fluctuations

作　　者：周济福[1] 张强[1] 李家春[1] 

机构地区：[1]中国科学院力学研究所,北京100080

出　　处：《应用数学和力学》2005年第10期1135-1142,共8页Applied Mathematics and Mechanics

基　　金：国家自然科学基金资助项目(1033205010002023);水资源与水电工程科学国家重点实验室开放研究基金资助项目(2003B003)

摘　　要：采用大涡模拟方法,模拟槽道湍流,获得了不同雷诺数情形下的槽道流大涡模拟数据库.在此基础上,获得了流向和垂向脉动速度的概率分布函数,并运用假设检验,分析了其与正态分布的定量差别.进一步计算了流向和垂向脉动速度的偏斜度、平坦度,讨论了二者在粘性子层、过渡区和对数律区的变化.同时,讨论了粘性子层、过渡区和对数律区流向和垂向脉动速度概率分布函数的特点及其与湍流猝发的高速流下扫和低速流喷发事件的关系.最后,分析了雷诺数对流向、垂向脉动速度分布的影响.By large eddy simulation （LFS）, turbulent databases of channel flows at different Reynolds numbers were established. Then, the probability distribution functions of the streamwise and wallnormal velocity fluctuations were obtained and compared with the corresponding normal distributions. By hypothesis test, the deviation from the normal distribution was analyzed quantitatively. The skewness and flatness factors were also calculated. And the variations of these two factors in the viscous sub-layer, buffer layer and log-law layer were discussed. Still illustrated were the relatios between the probability distribution functions and the burst events-sweep of high-speed fluids and ejection of low-speed fluids-in the viscous sub-layer, buffer layer and log-law layer. Finally the variations of the probability distribution functions with Reynolds number were examined.

关 键 词：近壁湍流 大涡模拟 脉动速度 概率分布函数 偏斜度 平坦度 

分 类 号：O357.52[理学—流体力学]