PROBABILITY DISTRIBUTION FUNCTION OF NEAR-WALL TURBULENT VELOCITY FLUCTUATIONS

• Published in: Applied mathematics and mechanics Vol. 26; no. 10; pp. 1245 - 1254
• Main Author: 周济福 张强 李家春
• Format: Journal Article
• Language: English
• Published: Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, P. R. China 01.10.2005
• Subjects: 旋转模拟; 概率分布函数; 正态分布; 速度波动; probability distribution function; large eddy simulation; skewness; near-wall turbulence; flatness; velocity fluctuation
• ISSN: 0253-4827; 1573-2754
• DOI: 10.1007/BF03246229

By large eddy simulation （LES）, turbulent databases of channel flows at different Reynolds numbers were established. Then, the probability distribution functions of the streamwise and wall-normal 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 sublayer, buffer layer and log-law layer were discussed. Still illustrated were the relations between the probability distribution functions and the burst events-sweep of high-speed fluids and ejection of low-speed fluidsIin the viscous sub-layer, buffer layer and loglaw layer. Finally the variations of the probability distribution functions with Reynolds number were examined.