【作者】 郑忠华；

【导师】 乐嘉陵； 吴其芬；

【作者基本信息】 中国人民解放军国防科学技术大学 ， 力学， 2003， 博士

【摘要】 在飞行马赫数M_∞=3-7的范围内，为充分发挥冲压发动机的性能优势，高超声速飞行器采用了既能在亚声速燃烧模态，又能在超声速燃烧模态下工作的固定几何形状的双模态冲压发动机。 双模态冲压发动机的地面试验研究同飞行器的空气动力学地面试验研究有很大的不同。进行双模态冲压发动机地面试验研究时，必须要求试验设备能模拟实际飞行条件下来流气体的组分、总压、总温(或总焓)以及来流气体的流动速度；同时由于燃料在燃烧室内驻留的时间很短，一般为毫秒量级，从而使流场物理量的测定显得非常困难。因此，双模态冲压发动机的研究对地面设备的试验能力和测量技术提出了更高的要求，也大幅度地增加了试验的周期和费用。而飞行试验因其费用昂贵只能做为最后的验证手段。随着计算机技术的发展和数值计算方法的进步，计算流体力学(CFD)在发动机的燃烧化学非平衡流场的数值计算研究方面得到了广泛的应用，并逐渐成为发动机设计和流动分析的一种经济、有效的手段。数值计算可以在相对较短的时间内完成气动参数的分析研究，提供流场的详细特征，弥补风洞试验及测量的局限性，为不断改进发动机的构型设计提供依据。 虽然双模态冲压发动机结构简单，主要由进气道、燃烧室和尾喷管三部分组成，但其工作过程却十分复杂，尤以超音速燃烧室的工作规律最为复杂，设计难度最大。它涉及到高超声速空气动力学、燃烧化学、扩散传质等多门学科；其内部的实际流动是复杂的三维流动过程，充满着激波、膨胀波、燃烧波、各种涡系、附面层及其相互之间的干扰，因此，燃烧室问题是整个发动机研究的关键所在。由于燃烧室内三维混合与燃烧流场的计算量很大，对程序要求较严，迄今为止，关于燃烧室流场的三维并行计算的研究工作，国内发表的文献非常少，网格节点在二十万左右，计算结果也无试验验证。国际上，直到最近，燃烧室流场的三维大规模并行计算才逐渐出现，网格节点数大约在20～250万。 根据国家“863”高超声速技术研究要求，本文建立了一套高效、实用的考虑燃料化学反应的双模态冲压发动机燃烧室流场的三维并行计算软件。为缩短计算时间和节约计算资源，针对试验模型，首先采用单片区域计算法，在工作站群机的PVM并行环境下进行了混合与燃烧流场的多区，多机并行计算，取得了较高的并行效率和与试验一致的计算结果。在此基础上将程序移植到神州MPP机上，采用512个CPU和大约312万个网格节点，对试验模型进行了三维大规模并行计算，第一次给出了模型发动机燃烧室流场的精细结构和完整的性能分析，获得了一些前人所没有得到的流场结构特性。 本论文共分为六章。第一章为引言，简要回顾了国内外双模态冲压发动机燃烧室研究的现状，并在结尾介绍了本文的主要工作。 第二章介绍了计算采用的控制方程与物理、化学模型。 第三章介绍了数值计算方法及其验证。本文运用时间相关法，采用格心有限体积离散，—-—通鲤登经军巡型遇逊生匕一一一一一独立建立和发展了-谁球解混合与燃烧流场的基于PVM环境的并行计算程序.通过简单的参数控制，该程序既可计算二维、轴又巾弥和三维量热完全气体，也可计算化判卜平衡流;既可计算无粘流，也可计算粘性流。该程序还可又州算区域进行分区计算，湍流模型也是可选的。通过计算程序应用于混合与燃烧算例的系列验证，检验了稠字编制的合理性和计算结果的可靠性. 第四章为在简化计算区域(单片区域法)的条件下，以氢气为燃料，在工作站群机上，数值模拟了日本国家航空实验室(简称NAL)双除瞰黔胜港型在油气比。=1 .0条件下流场的洋细至剖沟，分析了燃烧室流场与隔离段流场相互作用的产生机理和过程，掌握了相互作用流场的典型特征，并通过一维加权分析，给出了燃烧室的性肩崔参数。 第五章介绍了以氢气为燃料，同样应用单片区域法，对中国空气动力研究与发展中心 (简称CARDC)的双模态燃烧室模型在四种不同油气比条件下的流场结构进行了数值计算，给出了双模态燃烧室在不同参数条件下的流场结构特性和性编挂分析. 第六章介绍了在神州大规模并才刮比理衫比，采用512个CPU和大约312万个网格节点，对CARDC的试验模型进行了三维大规模并行计算，第一次给出了更加乖靓细的三维流娜吉构，包括燃烧室钡幢对流场结构和性能的影响。更多还原

【Abstract】 In the range of flight mach number Mo=3 ~ 7, in order to take the advantage of ramjet and scramjet, a fix-shaped dual-mode scramjet, in which both subsonic and supersonic combustion can be obtained, is used for hypersonic vehicle.There are great differences between ground test of a flight vehicle’s aerodynamics and that of a dual-mode scramjet When ground test facilities are used to do experiments on a dual-mode scramjet engine, the components of incoming flow and its parameters, including total pressure, total temperature (or total enthalpy) and velocity must be simulated. At the same time, since the fuel’s resident time within a combustor is very short, on the order of one millisecond, it is difficult to measure the flow-fields. So experimental study of dual-mode scramjet engines puts higher demands on simulating capability of ground test facilities and measurement technology, and greatly increases test cost and time. Flight test is more expensive and is taken only as a final means for verification. With the development of computer technology and the advancement of numerical calculation, Computational Fluid Dynamics (CFD) has been applied widely in simulating engine’s chemical non-equilibrium flowfields and has emerged as an extremely valuable and cost-effective engineering tool in engine design and flowfield analysis. CFD can be used to do analytical research of aerodynamic parameters in relatively short time, to provide detailed flowfield characteristics, to remedy the limitation of wind tunnel test and measurements, and to offer the foundation for improving the configuration of engine.Although a dual-mode scramjet’s configuration is simple and mainly consists of inlet, combustor and wake nozzle, its working process is complicated, especially in the combustor, involving a lot of subjects, including hypersonic aerodynamics, combustion chemistry, etc. The inner flow of a combustor is three-dimensional and complicated, including the interaction of shock wave, deflagration, vortex and boundary layer, and so on. So, combustor is the most important to dual-mode scramjet engine. The computation work of three-dimensional mixing and combustion simulation in combustor is very heavy, having strict requirements on the codes. Up to now, there are few domestic papers on 3-D parallel simulation of combustor flowfields. And abroad papers in this field are published gradually in recent years, with the number of grid about 200,000 to 2,500,000.According to the National Hypersonic Technology Plan, a highly efficient and practical three-dimensional parallel computing software for internal non-equilibrium flowfields of a dual-mode scramjet combustor has been established. In order to save calculating time, the parallelcomputation of simplified experimental dual-mode scramjet combustors has been implemented ona cluster of workstations based on PVM platform in a multidomain-multiprocessor manner. High parallel efficiency and fine results have been obtained. Using about 3,120,000 grid cells and 512 CPUs, the parallel program has been successfully transplanted to the SZ MPP machine for massive parallel computation, giving for the first time the detailed flow properties of a model engine’s combustor, offering a thorough performance analysis, and unprecedentedly obtaining some flowfield characteristics.This dissertation is divided into six chapters. In the introduction the review of the research on a dual-mode scramjet combustor both abroad and domestic is presented and the main work of this paper is also presented briefly. Chapter 2 describes the governing equations and the adopted physical and chemical method. Chapter 3 is about the numerical method. A parallel computing software is established independently. This software is a cell-centered finite-volume, structured grid, multi-block code which solves the equations governing inviscid and viscous flow of a calorically perfect gas or of an arbitrary mixture of thermally perfect gas undergoing non-equilibrium chemical reactions. It allows the flow domain to be d更多还原