气相爆轰极限是爆轰动力学的基础问题，相关研究对于发展爆轰控制技术具有重要意义，由于接近极限状态时爆轰波传播现象和机理的复杂性，诸多问题仍存在认识上的困难，尤其是针对有着广泛应用背景的多元混合燃料。本项目把合成气和参氢甲烷两种混合燃料作为研究对象，以不同体积比与氧气/空气组成气相多元燃料混合物，系统研究各混合物爆轰极限动力学特性。首先研究多元燃料混合物爆轰波在典型管道中传播和失效的动力学规律，以此建立判断爆轰极限的科学依据；进一步研究燃料浓度梯度、管壁粗糙度、热量损失、多元燃料的组分和工况、不稳定性等关键因素及其耦合作用对爆轰极限的定量影响机制；在上述基础上，提炼出能表征爆轰极限多因素耦合关系的等效参量，从而建立基于等效表征参量的爆轰极限定量预测模型。研究结果可拓宽和加深对多元混合燃料爆轰波接近极限状态动力学特征与规律的认识，有助于理解爆轰极限的复杂机理，为进一步研究气相爆轰物理提供依据。

The near detonation limits behavior is one of the fundamental problems of gaseous detonation dynamics, which is important for developing the detonation control technology. Due to the complexity of the phenomenon and mechanism of the detonation near its limits, some issues that we are still not fully understand and therefore need to be further explored. In this project, we mainly focus on the near detonation limits behavior in H2-CO-O2/air and H2-CH4-O2/air (called multi-component fuel mixtures) under different initial conditions, based on the consideration that those mixtures have a wide application background in industry. First of all, detonation propagation behaviors for multi-component fuel mixtures are investigated, the critical conditions that from detonation steady propagation to its failure are analyzed, a quantitative scientific basis for determining the detonation limits is developed base on the aforementioned work. Secondly, the key factors (i.e., concentration gradients, roughness of tube wall, heat loss, composition of different fuels, initial conditions, instability, etc) that affect the detonation limits are quantitatively studied. Lastly, the dynamic parameters of gaseous detonation limits are deeply analyzed, the characteristic parameters and theoretical prediction model for detonation limits are examined. The results may further the understanding of the features of detonation limits in multi-component fuel mixtures, which contributes to a better comprehension of the complicated mechanism of detonation dynamic characteristics and furthermore, provides important evidences for investigating detonation physics.