动力系统是高超声速飞行器的核心部件之一。基于扩散燃烧的超燃冲压发动机，需要较长的燃烧室和隔离段，这不仅带来了较大的结构重量也带来了较大的摩阻和热载荷。斜爆轰燃烧具有自点火、释热快、热循环效率高和燃烧稳定等特点。将其作为主要燃烧形式的斜爆轰发动机具有结构简单、燃烧室短、比冲高和燃烧稳定等优势，在高超声速吸气式推进领域具有重大应用潜力。自斜爆轰推进概念的提出（1940s）至今已有近80年，虽然取得了一定的研究进展，但是距离工程化应用还有较长的距离。这是由于斜爆轰推进中尚有一些关键技术问题未得到有效的解决。斜爆轰的形成对来流参数的变化非常敏感，因此在特定马赫数下设计的斜爆轰发动机遇到飞行速度下降时，斜爆轰波的起爆距离会急剧增大，甚至导致在燃烧室有限距离内不起爆。解决斜爆轰波的起爆问题对于拓宽斜爆轰发动机的飞行速域具有重要的意义。燃烧室内斜爆轰波-边界层作用引发的流动分离使得斜爆轰无法驻定在燃烧室内，传统的解决方案是采用溢流口，但这种方式不仅造成了比较大的流量损失，也难以工程化应用。因此解决斜爆轰波在燃烧室内的驻定问题具有重要工程意义。本文针对这两个问题进行了数值与实验研究。主要研究工作如下：

一、为实现低马赫数条件下斜爆轰波的强制起爆，以及提高斜爆轰波对来流扰动的抗干扰能力，本文提出了通过在诱导区内设置一个小鼓包来控制斜爆轰波起爆的方案，并通过数值求解二维多组分欧拉方程研究了楔面和鼓包诱导的斜爆轰波。结果表明：通过在诱导区内设置鼓包可实现斜爆轰波的提前起爆；且在较宽马赫数范围内，其起爆位置相对固定。鼓包诱导的斜爆轰波主要有强耦合和弱耦合两种起爆形式，起爆形式与鼓包和斜激波的相对位置有关。此外，来流扰动会使楔面诱导的斜爆轰流场剧烈振荡，不利于斜爆轰发动机的稳定工作；鼓包的存在对来流扰动所引发的斜爆轰波流场振荡具有一定的抑制作用。

二、斜爆轰波-边界层相互作用使流场呈现复杂的流动现象。本文通过数值模拟揭示了斜爆轰波过驱强度与燃烧室上壁面膨胀效应对流场驻定的影响规律。燃烧室中斜爆轰波的存在形式主要有以下四种：(a)不驻定，(b)过驱斜爆轰波弱解驻定，(c)过驱斜爆轰波强解驻定，(d)过驱斜爆轰波驻定。当斜爆轰波过驱强度较大，而膨胀较小时流场不驻定；过驱强度较小时，流场以弱解驻定，膨胀效应对流场结构基本无影响；斜爆轰过驱强度较大，膨胀较大时，流场出现强解驻定；过驱强度较大，膨胀角也比较大时，流场驻定，弱解强解同时出现。上壁面膨胀效应对流场的影响仅在斜爆轰波过驱强度较大时体现。

三、在JF-12复现高超声速飞行条件激波风洞中进行以液态航空煤油RP-3为燃料的斜爆轰发动机实验研究。提出并设计了强制起爆条来保证斜爆轰波的起爆成功，燃烧室内实现了两种驻定的爆轰燃烧模态：强爆轰燃烧模态和斜爆轰燃烧模态。同时进行了无强制起爆条的斜爆轰发动机对照实验，本文的实验结果表明：对于液态航空煤油，不能在无强制起爆条的燃烧室内起爆并形成斜爆轰波。

The power system is one of the core components of a hypersonic vehicle. The traditional scramjet is a hypersonic power system based on diffusion combustion, which requires a long combustion chamber and isolation section, which not only brings large structural weight, but also brings large friction and thermal load. Oblique detonation wave has the characteristics of self-ignition, rapid heat release, high thermal cycle efficiency and standing. As the main combustion organization, oblique detonation engine has the advantages of simple structure, short combustion chamber, high specific impulse and stable combustion, and has great application potential in the field of hypersonic air-breathing propulsion. However, it has been 80 years since the introduction of the concept of oblique detonation propulsion (1940s), although certain research progress has been made, there is still a long distance to engineering application. This is because there are still some technical problems in oblique detonation propulsion that have not been effectively solved. Because of the formation of the oblique detonation is sensitive to the change of the flow parameter, therefore under a certain speed design of oblique detonation engine, the speed (Ma) decrease oblique detonation initiation distance will increase sharply, even result in no initiation in combustion chamber limited range and therefore solve the problem of the oblique detonation initiation for broadening the oblique detonation engine flight field has important significance. The flow separation caused by oblique detonation wave/turbulent boundary-layer interaction in combustors makes oblique detonation unable to stay in combustors. The traditional solution is to adopt boundary layer bleed structure, but this method not only causes a relatively large flow loss, but also is difficult to be applied in engineering. Therefore, it is of great significance to solve the standing problem of oblique detonation wave in combustion chamber. In this paper, numerical and experimental studies are carried out for these two problems. The main research points are listed as follows:

1. In order to implement forced initiation of oblique detonation wave at low Mach numbers and to improve its capability of resisting disturbance to unsteady inflow, an idea of controlling initiation of oblique detonation wave by setting a small bump within its induction zone was proposed. Numerical simulations of oblique detonation waves induced by wedges and bumps were carried out by solving the two-dimensional multi-species Euler equations. Results show that initiation acceleration of oblique detonation wave can be implemented by setting a bump within the induction zone, and the initiation location keeps relatively fixed for a relative wide range of Mach number. There exist two initiation patterns for bump-induced oblique detonation wave, namely the strong coupled initiation and weak coupled initiation, depending on the location relationship between the bump and the oblique shock wave. Further, severe oscillation of wedge-induced oblique detonation wave would be induced by inflow disturbance, which is disadvantageous to the stable operation of oblique detonation engine. A certain inhibitory effect on the oscillation of oblique detonation wave induced by inflow disturbance can be observed with the inclusion of a bump.

2. The interaction between the oblique detonation wave and the boundary layer makes the flow field present a complex flow phenomenon. The flow field in combustion chamber of oblique detonation engine is studied by numerical simulation, and the influence law of overdrive intensity of the oblique detonation wave and expansion effect of upper wall of combustion chamber is revealed. There are four main forms of oblique detonation in combustion chamber: (a) non-standing, (b) weak solution standing, (c) strong solution standing, (d) overdriven oblique detonation wave standing (both weak solution and strong solution). When the overdrive intensity of oblique detonation wave is large and the expansion is small, the flow field is not standing. When the overdrive intensity is small, the flow field is standing with weak solution, and the expansion effect has little influence on the flow field structure. When the oblique detonation overdrive intensity is large and the expansion is large, the flow field appears strong solution standing. When the overdrive intensity is large and the expansion angle is relatively large, the flow field is standing and weak solution and strong solution appear simultaneously. The effect of upper wall expansion on the flow field is only reflected when the overdrive intensity of oblique detonation wave is large.

3. The experimental study of the oblique detonation engine fueled by liquid aviation kerosene (RP-3) was carried out in the hypersonic flight duplicated shock tunnel (JF-12). A forced initiation trip (FIT) is proposed and designed to ensure the successful initiation of the oblique detonation wave in the combustor. Two stationary detonation combustion modes are realized in the combustor: strong detonation combustion mode and oblique detonation combustion mode. At the same time, the control experiment of the oblique detonation engine without forced initiation trip was carried out. The experimental results in this dissertation showed that liquid aviation kerosene could not initiation and form oblique detonation wave in the combustor without forced initiation trip.