A dynamical systems analysis of high-Reynolds-number wall turbulence

高雷诺数壁面湍流的动力系统分析

• 批准号: EP/T009365/1
• 负责人: Yongyun Hwang
• 金额: $ 52.83万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FT009365%2F1
• 关键词: dynamical; systems; analysis; Reynolds; number

Turbulence in fluid flows over a solid surface (i.e. wall turbulence) is ubiquitous and central to the design of many aeronautical- and mechanical-engineering devices, such as aircraft wings, ship hulls, trains, cars, turbine blades, pipelines, and heat exchangers. The momentum transfer in wall turbulence is dominated by highly-organised energy-containing fluid motions, often referred to as coherent structures. There is a growing body of recent evidence that wall turbulence at high Reynolds numbers is organised into a hierarchy of self-similar, self-sustaining coherent structures, the size of which is proportional to their distance from the wall. Recently, the group of the applicant has discovered a set of exact solutions of the Navier-Stokes equations, which are directly linked with these self-similar coherent structures. In dynamical systems theory, such exact solutions form a skeleton of chaotic dynamics of turbulence in `state space'. Motivated by this recent discovery, this proposal aims to formulate and examine a dynamical-systems-theory-based description of wall turbulence at high Reynolds numbers. To this end, the present proposal sets out two work packages based on the state-of-the-art understanding of wall turbulence: 1) Computation of self-similar time-periodic solutions (periodic orbits) for the dynamics of individual coherent structures; 2) Dynamical systems analysis of minimal multi-scale (two-scale) wall turbulence. The outcome of this proposal will provide fundamental physical insight into the individual and collective dynamics of coherent structures in high-Reynolds-number wall turbulence. In particular, it will form a key building-block knowledge in a low-dimensional description of high-Reynolds-number wall turbulence. Ultimately, this will play a pivotal role in illuminating the precise `dynamical' mechanisms of turbulent skin-friction generation, heat transfer, and noise generation, the central processes underpinning many industrial designs.

在固体表面上的流体流动中的湍流（即壁湍流）是普遍存在的，并且是许多航空和机械工程设备（诸如飞机机翼、船体、火车、汽车、涡轮机叶片、管道和热交换器）的设计的核心。壁湍流中的动量传递由高度组织的含能流体运动（通常称为相干结构）主导。最近有越来越多的证据表明，在高雷诺数的壁湍流被组织成一个层次的自相似，自我维持的相干结构，其大小是成比例的距离壁。最近，申请人的小组已经发现了一组Navier-Stokes方程的精确解，其与这些自相似相干结构直接相关。在动力系统理论中，这种精确解构成了"状态空间"中湍流的混沌动力学的骨架。受这一新发现的启发，本文提出了一种基于动力系统理论的高雷诺数壁湍流描述方法。为此，本提案基于对壁湍流的最新理解提出了两个工作包：1）计算单个相干结构动力学的自相似时间周期解（周期轨道）; 2）最小多尺度（两尺度）壁湍流的动力学系统分析。这个建议的结果将提供基本的物理洞察到个人和集体的高雷诺数壁湍流相干结构的动力学。特别是，它将形成高雷诺数壁湍流的低维描述中的关键构件知识。最终，这将在阐明湍流表面摩擦产生、热传递和噪声产生的精确"动力学"机制方面发挥关键作用，这些机制是许多工业设计的核心过程。

项目成果

SPANWISE WALL OSCILLATION APPLIED TO EXACT COHERENT STATES OF PLANE COUETTE FLOW

翼展壁面振荡应用于平面库埃特流的精确相干状态

• 发表时间: 2022
• 期刊: 12th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2022
• 作者: Bengana Y.

Exact coherent states in plane Couette flow under spanwise wall oscillation

• DOI: 10.1017/jfm.2022.606
• 发表时间: 2022-08
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Yacine Bengana;Qiang Yang;Guohua Tu;Y. Hwang

Near-wall turbulence intensity as $Re_t\rightarrow \infty$

近壁湍流强度为 $Re_t ightarrow infty$

• DOI: 10.48550/arxiv.2306.14674
• 发表时间: 2023
• 作者: Hwang Y

Generalised quasilinear approximations of turbulent channel flow. Part 1. Streamwise nonlinear energy transfer

湍流通道流的广义拟线性近似：第 1 部分：流向非线性能量传递

• DOI: 10.1017/jfm.2022.59
• 发表时间: 2022-02-15
• 期刊: JOURNAL OF FLUID MECHANICS
• 影响因子: 3.7
• 作者: Hernandez, Carlos G.;Yang, Qiang;Hwang, Yongyun
• 通讯作者: Hwang, Yongyun

Generalised quasilinear approximations of turbulent channel flow: Part 1. Streamwise nonlinear energy transfer

湍流通道流的广义拟线性近似：第 1 部分：流向非线性能量传递

• DOI: 10.48550/arxiv.2108.12395
• 发表时间: 2021
• 作者: Hernández C