发动机燃烧涉及燃料不同组分之间、燃烧中间产物之间等众多的相互作用，微观上表现为不同组分间的相互碰撞，通常人们假设碰撞后分子的振转态迅速趋于平衡分布。但对含氢燃料，能级大的CH及OH键振动难以在发动机燃烧中达到平衡分布，且许多基元反应具有强烈的模式选择的特性，故研究碰撞过程中分子振转态分布的变化及其与后续反应的关系对宽温度和压力范围的燃烧过程很重要。目前，量子态分辨的研究多集中在单步反应碰撞，对考虑压力条件下不同反应间耦合的研究还非常少。本项目拟利用含时波包方法、多参考态含时动力学(MCTDH)和准经典轨线(QCT)方法，结合已有的精确势能面和反应力场（ReaxFF）研究碳氢燃料燃烧中重要的基元反应关联物间的碰撞反应、传能、模式选择及压力相关问题，考察多分子系统的三体效应及压力对反应速率常数的影响，探索碰撞传能及模式选择效应在基元反应速率、机理构建及简化、点火延迟、燃料设计方面的应用。

In engine combustion, there are many of the interactions among the different components and the intermediate products of the fuel. From a microscopic viewpoint, these interactions are realized by various collision processes. Usually, in a simulation, the vibrational-rotational states of the molecules is assumed to get the equilibrium distribution directly after a collision. While for the hydrocarbon fuel, vibrational-rotational states of the molecule needs too long time to get equilibrium distribution comparing with the period of the engine combustion, especially for the case of the excitation of CH or OH bond. Additionally, many of elementary reactions have a strong mode-specific feature. So the study of energy transfer and reaction in a collision process under the quantum state resolved level is very important for a wide range of combustion process. Currently, the study of quantum dynamics mainly focuses on the single-step reaction, but in a practical combustion, especially under the high pressure condition, the coupling effect between the corresponding reactions must be considered. Theoretically, the coupling effect must be described by quantum state resolved approaches. The project intends to use the multi-configuration time dependent Hartree method (MCTDH) and quasi-classical trajectory (QCT) method, combining with the reported potential energy surface and reaction force field (ReaxFF) to study the hydrocarbon fuel combustion. The collisional energy transfer, three-body effect, mode-specific reactions and the pressure dependent reactions will be mainly studied. While the corresponding application methods in the calculation of elementary reaction rate, the construction and simplification of combustion mechanism , the simulation of the ignition delay and the fuel design will be developed.