Engineering Research Equipment: A Combusting Flowfield Imaging System for the Study of One- and Two-Phase Reacting Flows

为探测单相和两相反应流的空间特性，将购买燃烧流场诊断系统。该系统由三个主要部件组成：(1)能够照射所研究的反应流的高脉冲能量的Nd：YAG激光器，(2)用于探测散射激光的高分辨率固态摄像机，以及(3)超级计算机工作站，其硬件专用于实时二维和三维图形操作，以控制激光器和探测器，分析和显示测量数据，并执行目前在超级计算机中心完成的计算任务。利用该装置进行的一些具体实验如下：(1)测量层流预混火焰和非预混火焰中的组分浓度和温度，(2)测量湍流火焰横截面内106个点的温度场及其全三维梯度；(3)利用受激拉曼散射或相干反斯托克斯拉曼散射确定燃烧液滴中的物种；(4)燃料液滴的同时光谱和空间成像，这将允许在单个激光脉冲中确定几个颗粒的尺寸和化学组成；以及(5)用电喷雾技术研究微米级固体颗粒在一定范围或聚集状态下的燃烧。激光诊断测量和计算方法对燃烧研究的潜在影响是巨大的。通过进行二维或三维测量，可以确定大尺度结构的特征，并研究流体运动与化学之间的相互作用。合作的实验和计算工作将使研究的两个部分都受益。

A Combusting Flowfield Diagnostic System is to be purchased for probing the spatial characteristics of one- and two-phase reacting flows. The system consists of three major components: (1) a Nd:YAG laser capable of high pulse energies to illuminate the reacting flow under study, (2) a high resolution, solid-state camera to detect the scattered laser light, and (3) a supercomputer workstation with hardware dedicated to real time two-and three-dimensional graphics operations to control the laser and detectors, analyze and display the measured data, and perform computational tasks currently done at supercomputer centers. Some specific experiments which will be performed with this equipment are as follows: (1) measurement of species concentrations and temperatures in laminar premixed and nonpremixed flames; (2) measurement of the temperature field and its full three- dimensional gradient at 106 points within a cross section of a turbulent flame; (3) determination of the species inside a burning droplet using stimulated Raman scattering or coherent anti-Stokes Raman scattering; (4) simultaneous spectral and spatial imaging of fuel droplets, which will allow the determination of size and chemical makeup of several particles in a single laser pulse; and (5) study of the burning of micron-sized solid particles in a range or aggregation regimes by electrospray techniques. The potential impact of laser diagnostic measurements and computational methods on combustion research is great. By performing measurements in two or three dimensions, the characteristics of large-scale structures can be determined and the interaction between the fluid motion and the chemistry studied. The cooperative experimental and computational effort will benefit both portions of the research.