雷诺数对湍流特性的影响

主要对近年来关于雷诺数（Ｒｅ）对湍流特性的影响的研究进行了回顾．研究表明除径向偏斜系数和平坦系数分布外，确实存在一个不受Ｒｅ数影响的区域，但对于不同的物理量这一区域的范围是不同的，即使是同一物理量不同研究者的结果亦不尽相同，显示了近壁区流动的复杂性和测量的困难，激光测速技术（ＬＤＶ）由于其具有测量精度高、不干扰流场、空间分辨率细等优点，近年来广泛地应用于对湍流，特别是对湍流近壁区流动特性及Ｒｅ数对湍流统计特性影响等的精细测量，随着ＬＤＶ自身及其它相关测试技术的进一步改进，ＬＤＶ在了解湍流产生机理、能量转换等方面发挥着越来越重要的作用．

THE EFFECTS OF REYNOLDS NUMBER ON TURBULENCE

The recent development of studies on Reynolds number (Re) on turbulence is reviewed.It is found that, except for the distributions of radial skewness and flatness factors, there exists aRe-dependence region. For different physical paraxneters, this region is different, and different resultsare obtained even for a same physical parameter. This means that the flow is complex in the nearwall region and it is difficult to measure precisely. Owing to the high precision, no disturbance tothe flow, fine spatial resolution etc., the Laser Doppler Velocimetery (LDV) has been widely usedto measure turbulent flow, especially to measure the characteristics of turbulence in the near wallregion and the Re-dependence on the statistic characteristics of turbulence. With the improvementof LDV and the relevant measurement technology, LDV will play a more and more important rolein ullderstanding the mechalnism of turbulence production, energy transportation etc.