湍流问题：如何看待“均匀各向同性湍流”？  

Turbulence question: How do view “the homogenous and isotropic turbulence”?

作　　者：赵松年[1] 胡非[1] 

机构地区：[1]中国科学院,大气物理研究所,大气边界层物理和大气化学国家重点实验室,北京100029

出　　处：《中国科学：物理学、力学、天文学》2015年第2期1-8,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:61271425)资助项目

摘　　要：在湍流的统计理论中,大气中的晴空湍流,风洞中格栅后面核心工作区的流动状态,都可以看作是均匀各向同性湍流,Kolmogorov的研究指出,能谱函数的惯性副区与均匀各向同性湍流相对应,标度律具有普适性,由此得出能量级串的著名的(?5/3)幂率.但是,在实验中观测到间歇性和拟序结构的情况下,应当对能量级串模型及其相应的各标度律进行比较研究,重点是探讨和研究它们的统计方法的物理机制.由于N-S方程中存在非线性项,特别是不封闭问题,使得理论研究和数值实验的结果具有多样性和复杂性,对此还没有任何有效的数学处理方法.本文以大气湍流为中心议题,论述了与此相关的几个主要问题,即:何为湍流难题,湍流理论与边界层理论,湍流难题的本质,大气湍流,湍流的定义问题,特别论述了3类不同的标度律,并展望了湍流研究的前景.In the statistical theory of turbulence, the clear-air turbulence in the atmosphere, the wind tunnel flow state in the core zone of the work area behind the grids, can be seen as a homogeneous and isotropic turbulence. Kolmogorov＇s study pointed out that the inertial set-range of spectrum function corresponds to homogeneous and isotropic turbulence; therefore, the scaling law is universal. From this, Kolmogorov deduced famous （-5/3） power law of turbulent energy cascade. But in the case observed intermittent and coherent structure in the experiments, it is needed to conduct comparative study between the energy cascade models and its corresponding scaling laws, the focus is to explore and study the physical mechanism of their statistical methods. Because there is a nonlinear term in N-S equation, especially the closure issues, which make the results of theoretical studies and numerical experiments have diversity and complexity, on this problem, there is no effective mathematical approach at present. In this paper, atmospheric turbulence as the central subject under discussion, several major issues related to this are discussed, namely： what is the problem of turbulence, turbulence theory and boundary layer theory, the nature of the turbulence problem, atmospheric turbulence, and the definition of the turbulence problem. We, especially, discuss the three different kinds of scaling laws, and look to prospects of turbulence research.

关 键 词：湍流 混沌 小波 世纪难题 Navier—Stokes方程 

分 类 号：O357.5[理学—流体力学]