爆轰是一种极端的燃烧现象，具有超声速自持传播、激波压缩自点火和释热速率快等特性，在高超声速飞行器推进、大型激波风洞驱动以及工业防爆方面具有重要的应用。爆轰波的传播过程耦合了多种物理现象的复杂相互作用，激波与化学反应之间的强相互作用造成了爆轰波特殊的内在不稳定性特征，研究和理解爆轰波内在不稳定性机制，对于实现爆轰燃烧的工程应用极其关键。随着计算机硬件和软件的迅猛发展，数值模拟已成为研究爆轰波起爆、传播以及流动机理的重要方法。本研究针对一维和多维爆轰波传播机理，采用计算流体力学方法对爆轰波流场进行数值仿真研究，探讨了与爆轰不稳定性相关的气动和化学反应耦合现象和机理，特别针对一维爆轰波驰振特征、二维爆轰波面结构演化以及三维爆轰波胞格空间结构特征等特定问题开展了分析研究，研究结果可以为爆轰波不稳定性特征的调控提供科学依据。本文获得的主要结论如下：

（1）针对一维脉动爆轰波和二维胞格爆轰波的传播不稳定性特征，通过调控化学反应活化能和速率常数，分析了爆轰波释热反应速率分布对爆轰传播规律的影响，发现对于具有相同反应区特征长度的爆轰波，不同活化能工况的一维脉动爆轰波驰振特征和二维胞格爆轰波面与胞格结构特征呈现出显著差异。通过分析一维脉动爆轰波失稳的临界不稳定数与活化能之间的联系，发现了高活化能工况释热反应速率对爆轰波局部过驱度变化高度敏感，是造成释热反应速率分布影响的主要物理机制。

（2）针对二维稳态胞格爆轰波在环管中的传播特性，数值模拟发现在不同的环管几何尺寸下，存在四种不同的传播模态，理论给出了这些模态随环管内外径比值变化的转变临界判据。数值研究发现内外壁附近爆轰波面的角位移差是形成不同爆轰波传播模式的主要物理因素，提出了调控爆轰波面角位移差的两种相互竞争作用机制，揭示了高活化能和非稳态爆轰传播模态极少出现马赫反射和规则反射的物理机理。

（3）针对斜爆轰波在低马赫数下难以驻定的问题，提出了一种利用有限长楔或双楔拐角产生膨胀波使斜爆轰波再驻定的方法。通过调控楔面长度和拐角大小，给出了爆轰波起爆并成功再驻定的临界判据。通过分析爆轰波驻定位置与双楔几何参数之间的联系，发现膨胀波的位置与作用范围是决定斜爆轰再驻定位置的关键因素。

（4）针对方管中传播的三维爆轰波流场结构，通过引入人工扰动研究了爆轰波的不同传播模式，分析了三维爆轰波“拍波”形成机理。数值研究结果显示三维爆轰波传播存在同相矩形模式、异相矩形模式和对角模式三种典型的传播模式，三维爆轰波壁面“拍波”的形成机制来源于爆轰波前锋中横波与壁面相互作用形成的横向高压条带的出现，分析了三维爆轰波面中横波运动与空间胞格结构的相互依赖关系。基于数值模拟结果，推导了典型传播模式下的三维爆轰波空间胞格结构的理论公式，获得了二维与三维爆轰波胞格结构关联特性。

Detonation is an extreme combustion phenomenon characterized by supersonic self-sustained propagation, shock wave compression ignition, and rapid heat release rates. It finds significant applications in the propulsion of hypersonic vehicles, driving large-scale shock tunnels, and industrial explosion prevention. The propagation of detonation waves involves complex interactions of multiple physical phenomena, with strong interactions between shock waves and chemical reactions leading to the distinctive inherent instability features of detonation waves. Investigating and understanding the mechanisms of inherent instability in detonation waves is crucial for the engineering applications of detonation combustion. With the rapid development of computer hardware and software, numerical simulation has become an important method for studying the initiation, propagation, and flow mechanisms of detonation waves. This dissertation focuses on the mechanisms of one-dimensional and multi-dimensional detonation wave propagation. Using computational fluid dynamics methods, numerical simulations are conducted to investigate the flow fields of detonation waves, exploring the coupled phenomena and mechanisms related to aerodynamics and chemical reaction instability in detonation waves. Specific analyses are conducted on issues such as the oscillatory characteristics of one-dimensional detonation waves, the evolution of two-dimensional detonation wave surface structures, and the spatial structure characteristics of three-dimensional detonation wave cells, aiming to provide a scientific basis for controlling the instability features of detonation waves. The main conclusions obtained in this dissertation are as follows:

(1) Regarding the instability characteristics of one-dimensional pulsating detonation waves and two-dimensional cellular detonation waves, by adjusting the activation energy and pre-exponential factor of chemical reactions, the impact of the distribution of heat release reaction rates on the propagation patterns of detonation waves is analyzed. Significant differences are observed in the oscillatory characteristics of one-dimensional pulsating detonation waves and the surface and cellular structure characteristics of two-dimensional cellular detonation waves for detonation waves with the same characteristic length of the reaction zone under different activation energy conditions. By analyzing the relationship between the critical instability number for the instability of one-dimensional pulsating detonation waves and the activation energy, it is found that high activation energy conditions render the heat release reaction rate highly sensitive to local detonation wave overdrive variations, serving as the primary physical mechanism affecting the distribution of heat release reaction rates.

(2) Concerning the propagation characteristics of two-dimensional steady cellular detonation waves in annular tubes, numerical simulations reveal the existence of four different propagation modes under various annular tube geometries. Theoretical criteria are provided for the transition of these modes with changes in the inner and outer diameter ratio of the annular tube. Numerical studies indicate that the angular displacement difference of the detonation wave surfaces near the inner and outer walls is the primary physical factor influencing the formation of different detonation wave propagation modes. Two competing mechanisms regulating the angular displacement difference of detonation wave surfaces are proposed, revealing the physical mechanisms behind the rarity of Mach reflection and regular reflection in high activation energy and unsteady detonation propagation modes.

(3) Addressing the challenge of stabilizing oblique detonation waves at low Mach numbers, a method involving the use of finite wedges or double wedges to generate expansion waves to re-establish oblique detonation waves is proposed. By adjusting the length of the wedge surface and the size of the corner, critical criteria for initiating and successfully re-stabilizing oblique detonation waves are provided. Through analyzing the relationship between the stabilization position of detonation waves and the geometric parameters of double wedges, it is found that the position and extent of the expansion wave are crucial factors determining the re-stabilization position of oblique detonation waves.

(4) Concerning the three-dimensional flow field structure of detonation waves propagating in square ducts, different propagation modes of detonation waves are investigated through the introduction of artificial perturbations, analyzing the mechanism of slapping waves in three-dimensional detonation waves. The numerical research reveals three typical propagation modes of three-dimensional detonation waves: in-phase rectangular mode, out-of-phase rectangular mode, and diagonal mode. The formation of slapping waves on the wall in three-dimensional detonation waves is attributed to the interaction of transverse waves with the wall, resulting in the appearance of transverse high-pressure bands. The interdependence between the transverse wave motion in three-dimensional detonation wave surfaces and spatial cellular structure is analyzed. Theoretical formulas for the spatial cellular structure of three-dimensional detonation waves under typical propagation modes are derived based on numerical simulation results, obtaining associated characteristics of cellular structures for two-dimensional and three-dimensional detonation waves.