基于DDES模拟的叶顶间隙流湍流特性研究  

Turbulence Characteristics of Tip Leakage Flow Based on DDES

作　　者：李会 苏欣荣[1] 袁新[1] LI Hui;SU Xin-Rong;YUAN Xin(Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2021年第2期342-348,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金面上项目(No.51876098)。

摘　　要：叶顶间隙泄漏流使得叶片顶部流动变得复杂,对间隙泄漏流的流动结构进行精细地捕捉并探讨其湍流特性有利于更深入的了解间隙泄漏流的流动机理,为控制泄漏损失提供依据。本文利用延迟脱体涡模拟方法对叶顶间隙泄漏流动进行非定常数值模拟;然后从叶顶间隙流的流动涡结构演变,湍动能和各向异性等方面研究叶顶间隙流的湍流特性;利用POD模态分解的方法对湍流特性做进一步分析,对分流场的基本规律、演变特点进行了详细研究;最后结合熵生成率,对泄漏流流动结构造成的损失进行了分析。研究发现,泄漏流在下游区存在着强湍流特性,涡尺度受不同的雷诺应力影响,且大尺度流动结构造成主要的耗散损失。Tip leakage flow caused by the tip gap makes the flow complicated near the blade tip region.Finely capturing the flow structure of tip leakage flow and discussing turbulence characteristics are beneficial to better understand the flow physics of tip leakage flow and also provide a reference for controlling the tip leakage flow loss.In this paper,the Delayed Detached Eddy Simulation(DDES)method is used to simulate the unsteady flow of tip leakage flow.Then.the turbulence characteristics of tip leakage flow are studied from the aspects of flow vortex structure evolution,turbulent kinetic energy and anisotropy.In addition,the turbulence characteristics are further analyzed by the method of Proper Orthogonal Decomposition(POD).and the evolution characteristics of the decomposition flow field are investigated in detail.At last,the loss of leakage flow is analyzed based on entropy generation rate.Overall,it is found that the tip leakage flow has strong turbulence characteristics in the downstream region,and the vortex scale is affected by different Reynolds stress where the large-scale flow structure causes the main dissipation loss.

关 键 词：DDES 叶顶泄漏流 湍流特性 模态分解 

分 类 号：TK472[动力工程及工程热物理—动力机械及工程]