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

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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.