动态压力畸变下压缩系统稳定性分析

基于逐级压缩系统模型，发展了一种动态压力畸变下压缩系统失稳识别的数值预测方法。应用方法对一多级轴流压缩系统进行了数值分析。给出了动态压力脉动频率与压缩系统失稳首发级及不稳定发生时间之间的定量关联关系。     

某型涡扇发动机进气总压畸变的试验研究

由可移动插板式畸变发生器产生进气总压畸变流场,以综合畸变指数评定流场畸变程度,分析了进气总压畸变对涡扇发动机气动稳定性的影响,得到了稳态总压场不均匀度与总压紊流度随插板深度及发动机转速的变化关系,确定了该型发动机的最大（或临界）综合畸变指数和总压畸变敏感系数。     

超燃冲压发动机非对称喷管非设计状态性能计算

由非对称喷管的设计程序,以实际飞行马赫数6为设计条件,取不同的几何控制参数,获得一系列对应的喷管等熵型线。对其进行附面层修正后,在不同飞行工况下,用CFD软件分别对不同外型的喷管流场进行了计算,讨论了上下壁面进口处初始膨胀角之比F对非设计工况下喷管性能的影响。然后,对F=0的喷管型线截去约60%,用CFD软件计算了不同飞行工况下的流场,讨论了截短对非对称喷管非设计状态性能的影响。结果表明:F对非设计状态喷管性能影响显著;截短后喷管进出口冲量差减小,升力和俯仰力矩减小。     

侧压式进气道内部阻力的参数分析

为明确高超声速进气道内部阻力的特点,并为进气道减阻设计提供参考依据,以侧压式进气道为例,分别以内壁面和捕获流管为分析体,讨论进气道不同几何设计参数下的阻力特性;以数值模拟为手段,给出了总阻力的大小及各项阻力的分配比例,并分析了进气道几何参数变化对阻力的影响关系。给出了侧压式进气道附加阻力作用表面的形状,讨论了附加阻力的特点。研究发现,内壁面总阻力中,压力阻力随收缩比增加而增加,约占总阻力的60%到70%;唇口前的溢流会产生“附加推力”而不是通常情况的附加阻力。     

航天飞机用冲压发动机设计性能及燃料问题

本文论证了高M_α数亚燃冲压发动机用于航天飞机的可能性。并对用液氢、甲烷、丙烷等作为燃料的冲压发动机特性作了详细的计算分析。讨论了冲压发动机的工作菱形区、发动机特性及各截面的协调关系等问题。计算结果表明,在M_α=2～6及H=0～40km范围内,亚燃冲压发动机能满足航天飞机对动力装置的要求。在一定的条件下,液氢、甲烷和丙烷均可以被选为航天飞机用的冲压发动机的燃料。     

Review of control and guidance technology on hypersonic vehicle

Air-breathing hypersonic vehicle has great military and potential economic value due to its characteristics: high velocity, long range, quick response. Therefore, the development of hypersonic vehicle and its guidance and control technology are reviewed in this paper. Firstly, the development and classification of hypersonic vehicles around the world are summarized, and the geometric configuration and mission profile of typical air-breathing hypersonic vehicle are given.Secondly, the control dif...     

Numerical simulation of hypersonic thermochemical nonequilibrium flows using nonlinear coupled constitutive relations

To predict aeroheating performance of hypersonic vehicles accurately in thermochemical nonequilibrium flows accompanied by rarefaction effect, a Nonlinear Coupled Constitutive Relations (NCCR) model coupled with Gupta’s chemical models and Park’s two-temperature model is firstly proposed in this paper. Three typical cases are intensively investigated for further validation, including hypersonic flows over a two-dimensional cylinder, a RAM-C II flight vehicle and a type HTV-2 flight vehicle. The results predicted by NCCR solution, such as heat flux coefficient and electron number densities, are in better agreement with those of direct simulation Monte Carlo or flight data than Navier-Stokes equations, especially in the extremely nonequilibrium regions, which indicates the potential of the newly-developed solution to capture both thermochemical and rarefied nonequilibrium effects. The comparisons between the present solver and NCCR model without a two-temperature model are also conducted to demonstrate the significance of vibrational energy source term in the accurate simulation of high-Mach flows.     

在进气道与发动机相容性方面反旋流措施的工程应用研究

进气道旋流是进气道与发动机相容性的一个重大扰动参数，从飞机总体布局，发动机设计方面入手，研究了现存飞机对旋涡的防止和反抗措施，新发现：低压压气机前面级静子叶片采取“端弯”技术措施，对提高发动机抗旋流扰动能力，降低对旋流扰动的敏感度十分有利，看好其工程应有前景。     

S形进气道和发动机相容性

进气道旋流是进／发相容性的一重大扰动参数。在发动机稳定和性能方面进气道旋流的效应也是不可忽视的。讨论了Ｓ形进气道／发动机相容性的评定方法，并且建议了有效评定准则。Ｓ形进气道／发动机相容性评定必须由两部分组成，一部与压力畸变有关，而另一部分与流动弯曲度有关。     

Numerical simulations of high enthalpy flows around entry bodies

Ablation flows around entry bodies are at highly nonequilibrium states. This paper presents comprehensive computational fluid dynamics simulations of such hypersonic flow examples.The computational scheme adopted in this study is based on the Navier–Stokes equations, and it is capable of simulating multiple-dimensional, non-equilibrium, chemically reacting gas flows with multiple species. Finite rate chemical reactions, multiple temperature relaxation processes, and ionizations phenomena with electrons are modeled. Simulation results of several hypersonic gas flows over axisymmetric bodies are presented and compared with results in the literature. It confirms that some past treatment of adopting less species for hypersonic flows is acceptable, and the differences from more species and more chemical reactions are not significant.