尽管有为许多十年的奉献努力,对的统计描述高度,技术上重要的墙骚乱仍然是大挑战。当前的模型不幸地不完全,或实验,或质。在墙骚乱的存在理论的评论以后,我们在场一个新框架,把结构整体动力学(SED ) 称为,它瞄准集成骚乱动力学进对吝啬的流动的量的描述。SED 理论自然地亲密地从非平衡理解开的系统的一个统计物理演变,例如液体骚乱,为平均数,数量是结合了变化动力学。从平均整体的 NavierStokes (EANS ) 方程开始,理论要求为墙骚乱产出一幅多层的图画的统计状态的一个有限数字的存在。然后,描绘在状态之间的状态和转变使用顺序功能(在象精力方程一样的吝啬的动量的术语的比率) 。到不可压缩的隧道流动和可压缩的狂暴的边界层的 SED 分析的申请证明顺序函数成功地为围住墙的骚乱揭示多层的结构,它以亚层作为传统的看法的量的扩展产生,缓冲区层,日志层并且醒来。而且,使用一套夸张功能为在层之间的转变建模的一个想法越过全部流动领域为顺序功能的一个量的模型被建议。我们断定 SED 提供一个理论框架因为表示变化的还未知的效果在吝啬的数量上组织,并且把新方法提供给试验性的分析和模拟数据。与 asymptotic 分析结合了,评估模拟的集中也提供一个方法。SED 途径成功地在动量和精力层次描述动力学,在有仅仅描述吝啬的速度侧面的所有流行途径的对比。而且, SED 理论框架是一般的,独立于到学习的流动系统,当顺序功能的实际功能的形式可以从流动变化到时流动。我们作为功能被积累的顺序的知识并且作为更多的流动维护那被分析的、新原则(例如层次,对称,组不变性,等等) 在吝啬的流动性质管理狂暴的结构的角色将被澄清,骚乱的一个可行理论可能出现。
Despite dedicated effort for many decades,statistical description of highly technologically important wall turbulence remains a great challenge.Current models are unfortunately incomplete,or empirical,or qualitative.After a review of the existing theories of wall turbulence,we present a new framework,called the structure ensemble dynamics (SED),which aims at integrating the turbulence dynamics into a quantitative description of the mean flow.The SED theory naturally evolves from a statistical physics understanding of non-equilibrium open systems,such as fluid turbulence, for which mean quantities are intimately coupled with the fluctuation dynamics.Starting from the ensemble-averaged Navier-Stokes(EANS) equations,the theory postulates the existence of a finite number of statistical states yielding a multi-layer picture for wall turbulence.Then,it uses order functions(ratios of terms in the mean momentum as well as energy equations) to characterize the states and transitions between states.Application of the SED analysis to an incompressible channel flow and a compressible turbulent boundary layer shows that the order functions successfully reveal the multi-layer structure for wall-bounded turbulence, which arises as a quantitative extension of the traditional view in terms of sub-layer,buffer layer,log layer and wake. Furthermore,an idea of using a set of hyperbolic functions for modeling transitions between layers is proposed for a quantitative model of order functions across the entire flow domain.We conclude that the SED provides a theoretical framework for expressing the yet-unknown effects of fluctuation structures on the mean quantities,and offers new methods to analyze experimental and simulation data.Combined with asymptotic analysis,it also offers a way to evaluate convergence of simulations.The SED approach successfully describes the dynamics at both momentum and energy levels, in contrast with all prevalent approaches describing the mean velocity profile only.Moreover,the SED theoretical fr