Fundamental Detonation Characteristics and their Influ- ence in Rotating Detonation Engines

爆震波是一种非常快速、高压和高温的现象，在这种现象中，冲击波最初会引发化学反应。它们的剧烈性质使它们成为一个令人感兴趣的主题，无论是从缓解的角度来看，工业环境都会因这种波浪的意外形成而遭到破坏，还是高效率、先进推进系统的基石。该提案最感兴趣的是前者，最近开始以旋转爆轰发动机（RDE）的形式实现。考虑到装置的连续运行，作为其核心操作一部分的爆震波遇到的环境与通常研究爆震的静态均匀环境非常不同。在这种情况下，注入在波前产生了大量的湍流，新鲜反应物和最近燃烧产物之间的剪切层产生了湍流结构，与波的传播相互作用。为了应对这种恶劣的环境，必须开发更多关于爆震波基本结构的知识，特别是对于具有不规则结构的爆震波，因为最有可能产生这种波的候选燃料。本提案旨在研究代表RDE运行的环境，以及探测爆震波的内部结构，以揭示其基本尺度。设计了一种新的实验，在该实验中，平面爆震波以放牧的方式与一层强度可控的湍流相互作用。本文将采用这种新的实验装置和相同实验装置的数值模拟相结合的方法，研究影响规则和不规则爆震波传播动力学的条件和方式。结合对爆震波与外部涡动源相互作用的探索，这一建议为仔细研究自生湍流在爆震结构本身中的作用奠定了基础。这与目前使用的平均方法不同，而是采用采样方法，其中大量拉格朗日粒子通过爆轰结构进行跟踪。该方法将在Euler方程和Navier-Stokes方程的数值模拟中实现。利用拉格朗日采样信息，可以推断出反应速率对湍流混合的依赖性，并在下一代爆震波工程模型中实现。

Detonation waves are a very rapid, high pressure and temperature phenomenon within which shock waves initially trigger chemical reactions. Their violent nature makes them a subject of interest both from the point of view of mitigation, where industrial environments would be devastated by the accidental formation of such a wave, as well as a building block in high efficiency, advanced propulsion systems. This proposal is most interested in the former, which has recently started materializing in the form of the Rotating Detonation Engine (RDE). Given the continuous operation of the device, the detonation waves that are part of its core operation encounter an environment very different from the quiescent, homogeneous environment in which detonations are typically studied. In this case, injection creates substantial turbulence ahead of the wave and shear layers between fresh reactants and recently combusted products create turbulent structures that interact with the propagation of the wave. To tackle this harsh environment, more knowledge must be developed about the fundamental structure of detonation waves, especially for detonations with an irregular structure since the most likely candidate fuels would produce such a wave.This proposal seeks to both study environments representative of the operation of an RDE as well as probe the internal structure of detonation waves to reveal its fundamental scales. A novel experiment is devised in which a plane detonation wave interacts in a grazing fashion with a sheet of turbulence of a controlled intensity. The conditions and manner in which the propagation dynamics of regular and irregular detonation waves are influenced will be studied using a combination of this new experimental configuration and numerical simulations of this same experimental setup.In conjunction with the exploration of the interaction of a detonation wave with an outside source of vortical motion, this proposal lays the foundation for a careful examination of the role of self-generated turbulence within the detonation structure itself. This is done by departing from the currently used averaging methods and, instead, employing a sampling method in which a large number of Lagrangian particles are followed through the detonation structure. This method will be implemented on numerical simulations of the Euler and Navier-Stokes equations. Using Lagrangian sampling information about the dependence of reaction rates on turbulent mixing can be inferred and implemented in next-generation engineering models of detonation waves.