超音速流场中多波系干扰结构识别方法与应用研究

发布时间：2017-12-27 21:42

本文关键词：超音速流场中多波系干扰结构识别方法与应用研究　出处：《清华大学》2016年博士论文　论文类型：学位论文

【摘要】：超声速尤其高超声速飞行器流场结构非常复杂。典型的流动结构包括激波、膨胀波、剪切层、涡。这些流场结构之间发生相互干扰,产生新的次生结构,例如激波反射、激波干扰、激波附面层干扰等导致新的结构,使得流场进一步复杂化。这些结构对飞行器会产生各种正面及负面作用。本文针对超声速流场中的激波、膨胀波、剪切层这些典型波系结构及其干扰,基于这些结构所满足的物理规律,给出了从结果中自动识别提取这些结构的算法以及典型波系结构满足的基本关系,尤其改进了激波识别算法。并在此基础上,建立了用于CFD计算结果后处理的结构识别平台。本文发展的结构识别平台的作用包括:1)能读取常用的CFD计算结果标准格式文件;2)展示云图、等值面、切面、流线、矢量图等传统图形;3)自动提取激波面、线,提取膨胀波区域,提取剪切层区域;4)对各种提取的结构进行图形展示,并提取前后参数;5)对结果进行数值纹影展示。本研究减小了传统方法存在的流场结构误识别、漏识别或无法识别等困难。所得到方法用在基础研究中,有利于正确研究干扰结构等机理问题。在工程应用中,有利于判断波系结构的位置和强度,对于有利结构加以利用,不利结构加以控制。在采用CFD等获取流场时,准确识别结构还可以为在局部选用更精密的网格和物理模型提供指导。作为应用,将结构识别方法用于吸气式发动机超声速进气道的波系结构识别,也用在某特定升力构型流场结构分析中。在这些应用中,分析了一些复杂的激波干扰现象。本文针对复杂外形与复杂波系结构流场得到的结构识别平台,具有结构识别简单、流场结构展示直观、可处理各种标准数据格式和各种网格类型与外形等实用特征,大大降低了复杂流场的机理分析难度和处理工程问题的难度。
[Abstract]:The flow field structure of supersonic especially hypersonic vehicle is very complex. A typical flow structure consists of shock waves, expansion waves, shear layers, and vortices. These flow fields interact with each other, resulting in new secondary structures, such as shock wave reflection, shock wave interference, shock wave boundary layer interference, and so on, leading to new structure, which makes the flow field more complex. These structures have a variety of positive and negative effects on the aircraft. In this paper, aiming at the shock wave in supersonic flow of the expansion wave, the shear layer of these typical wave structure and interference, the laws of physics to meet these structure based on the automatic recognition algorithm of extraction of these structures from the results and the basic relationship between the typical wave structure meet the given improved recognition algorithm, especially the shock. On the basis of this, a structure recognition platform for the post processing of CFD calculation results is set up. Including the structure recognition platform: 1) to read the common CFD results of the standard format; 2) display images, isosurface, view, streamline and vector diagram of the traditional graph; 3) automatically extract the shock surface, line extraction, expansion wave region, extraction of shear layer region; 4) on the structure all kinds of extracted graphics display, and extract the parameters before and after 5); the results are numerical schlieren display. This study reduces the difficulties of error identification, leakage identification, or identification of the flow structure in the traditional method. The method used in the basic research is beneficial to the correct study of the mechanism of interference structure. In the engineering application, it is beneficial to judge the position and strength of the structure of the wave system, to use the favorable structure, and to control the unfavorable structure. When using CFD to obtain the flow field, the accurate identification of the structure can also provide guidance for the selection of more precise grids and physical models in the local area. As an application, the structure identification method is applied to the identification of the wave structure of the supersonic inlet of the suction engine, and is also applied to the analysis of the flow structure of a specific lift configuration. In these applications, some complex shock interference phenomena are analyzed. In this paper, the complex shape and complex wave flow system structure identification platform, structure is simple identification, flow structure, processing and display the format of various grid type and shape the practical characteristics of various standard data, greatly reducing the mechanism of complex flow field analysis of the difficulty and the difficulty of the problem processing engineering.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O354.3

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