湍流的Markov过程理论与Kolmogoroff理论的联系以及对制Kolmogoroff定律的推广——Ⅰ.对两个理论关系的分析
The Relation between Markov Process Theory and Kolmogoroff’s Theory of Turbulence and the Extension of Kolmogoroff’s Laws——I. The Analysis of the Relation between the Two Theories
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摘要: 本文全文分为两部分(Ⅰ和Ⅱ).第Ⅰ部分讨论了关于大雷诺数湍流的两种理论——拉格朗日观点的Markov过程理论与欧拉观点的Kolmogoroff理论之间的联系.指出:对位置和速度的联合过程进行Markov描述所需雷诺数与Kolmogoroff第二相似性假设所需雷诺数同样大;周期与Tu和Tf同阶的旋涡分别对应于Kolmogoroff理论的含能范围与耗损范围;Richarson定律的适用范围T*≤t≤β-1对应于Kolmogoroff理论的惯性子范围,从而指出,两种理论从不同侧面反映了大雷诺数湍流的流场结构.在本文第Ⅱ部分,我们将利用第Ⅰ部分中阐述的物理想法以适当方式建立两种理论之间的某种定量的联系.从而由拉格朗日观点的弥散运动的结果得出欧拉观点的结构函数、关联函数和能谱函数.所得结果不但适用于惯性子范围,而且适用于尺度更大(或波数更小)的全部范围.熟知的Kolmogoroff“2/3定律”和“(-5)/3定律”为本结果在惯性子范国的渐近解.因而本结果是Kolmogoroff“2/3定律”和“(-5)/3定律” 的推广.Abstract: The whole paper consists of two parts (Part Ⅰ and Part Ⅱ). In part X/we shall analyze the relation between the two theories of turbulence involving large Reynolds number:the Markov process theory from the La-grangian point of view and Kolmogoroff's theory from the Eulerian point of view. It will be pointed out that the Reynolds number needed for the Markovian description of turbulence should be as large as.that..needed for Kolmogoroff's second hypothesis, that the eddies of the period of order T,(the self-correlation time scale of the random velocity u) and the eddies of the period of order Tu (the self-correlation time scale of the random force f) correspond to the energy-containing eddies and the eddies in the dissipation range respectively, and that T*≤t≤β-1 the time interval for the applicability of Richardson's law during two-particle's dispersion, corresponds to the inertial subrange in Kolmogoroff's theory. Thus, these two theories reflect the property of the turbulence involving very large Reynolds number arguing from different-aspects.In Part Ⅱ, by using physical analysis in Part I, we shall establish in a certain way the quantitative relation between these tvo'theories. In terms of this relation and the results of the study of two-particle's dispersion motion, we shall obtain the structure functions, the correlation functions and the energy spectrum, which are applici-able not only to the inertial subrange,but also to the whole range with the wave number less than that in the inertial subrange.Kolmogoroff's "2/3 law" and "-5/3 law" are the asymptotic solutions with respect to the present result in the inertial subrange. Thus, the present result is an extension of Kolmogoroff's Jaws.
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[1] 岳曾元,李荫亭,关德相,张彬,中国科学,2,(1974),148 [2] Kolmogoroff,A.,The local structure of turbulence in an incompressible viscous fluid for very large Regnolds number(1941),in:Turbulence,Classic Papers on Statistical Theory,Ed.S.K.Friedlander and Leonard Topper,(1961). [3] Kolmogoroff,A.,On degeneration of isotropic turbulence in an incompressible viscous liquid,ibid,(1941).见同上书. [4] Kolmogoroff,A.,Dissipation of energy in the locally isotropic turbulence ibid.,(1941). [5] Krassnoff,E.and R.L.Peskin,Geophysical Fluid Dynamics,2,(1971),123-146. [6] 王梓坤、《概率论基础及其应用》,科学出版社,(1976). [7] Hinze,J.O.Turbulence,McGraw-Hill,Inc.(1975). [8] Obukhov,A.M.,Advances in Geophysics,6,(1959),113. [9] Stewart,R.W and A.A.Townsend,Phil.Trans.Roy.Soc.London,243A,(1951),359. [10] Chandrasekhar,S.,Review of Modern Physics,15,(1943),1-89.
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