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

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。申请资金用于开发一种独特的高脉冲能量（~1 J/脉冲）激光系统，该系统将实现定量超高帧率（20 kHz）粒子成像测速（PIV）、平面激光诱导荧光（PLIF）、瑞利散射和拉曼散射诊断，用于在大量时间记录（多达1000张连续图像）上进行多维度的温度、速度和物种浓度测量。提出的激光系统将用于在时间和空间上解决在湍流燃烧环境中发生的最精细的空间和时间尺度上的控制物理和化学过程。燃烧过程本身具有时间依赖性和空间复杂性，因此高速成像诊断的新时代对于解决最终控制火焰稳定性、燃烧效率和化学物质（污染物）产生的波动速度和标量至关重要。由于缺乏可用的激光技术，详细描述湍流火焰的时间演化性质的实验非常少。一个成功的仪器开发项目将产生一种测量能力，这将促进对化学反应流的新的基本理解，这在世界上任何地方都无法复制。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高度间歇性湍流流场之间的时间依赖性耦合的新信息，这些信息以前没有被详细探索过。举例来说，本地燃料/空气/产品混合和燃烧稳定性将在从实验室规模的火焰到高压、多相流发动机条件的配置层次结构中进行检查。此外，所提出的系统将产生一种新的能力，通过直接支持预测、多尺度、随时间变化的燃烧模型的进步，鼓励实验家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.