Characterization of Scalar Correlations In Turbulent Counterflow Nonpremixed Flames

这是对湍流射流火焰中标量波动的研究。 在一个简化的逆流几何的空间和时间结构进行了研究。 的几何形状是有益的定量实验结果和先进的湍流燃烧模型，如大涡模拟之间的直接比较。 使用由两个相对的喷嘴组成并提供一系列湍流条件的模块化燃烧器。 定量激光诊断应用到一系列的火焰在这个燃烧器恢复的OH和CH浓度，温度和混合物分数的时间依赖性。 速度测量是在达姆施塔特工业大学的一个相同的燃烧器上获得的。 在赖特-帕特森空军基地进行了一组同时进行的速度和浓度测量。 利用研究者开发的模拟技术，空间和时间的相关性之间的关系进行了定量研究。湍流射流火焰中的次要组分浓度的时间序列测量最近已经取得。 这些单点测量允许时间尺度统计的研究，并且类似于空间尺度成像。 然而，未知的混合统计在射流火焰复杂的解释这些数据。

This is a study of scalar fluctuations in turbulent jet flames. Spatial and temporal structures are studied in a simplified counterflow geometry. The geometry is conducive to direct comparison between quantitative experimental results and advanced turbulent combustion models such as large-eddy simulations. A modular burner consisting of two opposed jets and providing a range of turbulent flow conditions is used. Quantitative laser diagnostics are applied to a series of flames in this burner to recover the time dependence of OH and CH concentrations, temperature, and mixture fraction. Velocity measurements are obtained on an identical burner at Technische Universitat Darmstadt. A set of simultaneous velocity and concentration measurements are made at Wright-Patterson Air Force Base. Using a simulation technique developed by the investigators, relationships between spatial and temporal correlations are examined quantitatively.Time-series measurements of concentrations of minor species in turbulent jet flames have been made recently. These single-point measurements permit study of time-scale statistics and are analogous to spatial-scale imaging. However, unknown mixing statistics in the jet flames complicate interpretation of these data.