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

点击翻译按钮获取中文摘要

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.