MRI: Development of a High Energy, High-Repetition-Rate Laser Diagnostic System for Time-Resolved Investigations of Turbulent Combustion Processes

该奖项由2009年美国复苏和再投资法案(公法111-5)资助。0923340Sutton Funding被要求开发一种独特的高脉冲能量(~1J/脉冲)激光系统，该系统将能够实现定量的超高帧频(20 KHz)粒子成像测速(PIV)、平面激光诱导荧光(PLIF)以及瑞利和拉曼散射诊断，以在大量的时间记录(多达1000张序列图像)上进行多维温度、速度和物种浓度的测量。拟议的激光系统将被用来在时间上--和空间上--解析在湍流燃烧环境中在最精细的空间和时间尺度上发生的主导物理和化学过程。燃烧过程本质上是时间相关和空间复杂的，因此，新一代高速成像诊断对于解决波动的速度和标量至关重要，这些波动和标量最终控制着火焰的稳定性、燃烧效率和化学物种(污染物)的产生。由于缺乏可用的激光技术，详细描述湍流火焰随时间演变的性质的实验的稀缺性受到了严重限制。一个成功的仪表开发计划将产生一种测量能力，这将促进对化学反应流动的新的基本理解，这些流动是世界上任何地方都无法复制的。对速度、温度和物质浓度的高速测量将产生关于关键化学反应和以前尚未详细探索的高度间歇性湍流流场之间的时间依赖耦合的新信息。例如，将在从实验室规模的火焰到高压多相流发动机条件的层次结构中检查本地燃料/空气/产品的混合和燃烧稳定性。此外，拟议的系统将产生一种新的能力，通过直接支持预测的、多尺度的、随时间变化的燃烧模型的发展，鼓励实验者和理论家之间的合作。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).0923340SuttonFunding is requested to develop a unique high-pulse-energy (~1 J/pulse) laser system that will enable quantitative ultra-high-frame-rate ( 20 kHz) Particle Imaging Velocimetry (PIV), Planar Laser-Induced Fluorescence (PLIF) and Rayleigh and Raman scattering diagnostics for temperature, velocity, and species concentration measurements in multiple dimensions over substantial temporal records (up to 1000 sequential images). The proposed laser system will be used to temporally- and spatially-resolve the governing physical and chemical processes occurring at the finest spatial and temporal scales in turbulent combustion environments. Combustion processes are inherently time-dependent and spatially-complex, thus a new era of high-speed imaging diagnostics are critical for resolving the fluctuating velocity and scalar quantities that ultimately control the flame stability, combustion efficiency, and chemical species (pollutant) production. The scarcity of experiments detailing the temporally-evolving nature of turbulent flames has been severely constrained by the lack of available laser technology. A successful instrumentation development program will result in a measurement capability that will facilitate a new fundamental understanding of chemically reacting flows that cannot be duplicated anywhere in the world. High-speed measurements of velocity, temperature, and species concentrations will yield new information on the time-dependent coupling between key chemical reactions and the highly intermittent turbulent flowfield that has not been explored in detail previously. As examples, the local fuel/air/product mixing and combustion stability will be examined in hierarchy of configurations ranging from laboratory-scale flames to high-pressure, multi-phase flow engine conditions. In addition, the proposed system will result in a new capability that encourages the collaboration between experimentalists and theoreticians by directly supporting the advancement of predictive, multi-scale, time-dependent combustion modeling.