CAREER: The Study of Turbulence and Compressible Flows Using Molecular Filter Based Diagnostics

申请号：CTS-9733388首席研究员：Elliott湍流和可压缩流动的分子过滤器诊断研究CAREER奖的主要目标是支持一种称为过滤角分辨瑞利散射（FARRS）的非侵入式流动诊断技术的发展，该技术将同时测量瞬时速度、密度、温度和压力。该技术测量了ND:YAG脉冲激光聚焦光束从点测量体产生的散射，并对其流进行了询问。采用变形光学系统分别记录不同角度的瑞利散射信号。将图像记录到加强型CCD相机上，可得到强度与视角剖面的关系。通过在相机前放置一个碘滤光片，并将激光调谐到碘的吸收线上，CCD上记录的散射强度和视角轮廓会根据流速、密度、温度和压力的变化而改变形状。每个瞬时（10ns）激光脉冲的轮廓可以用来计算流体性质。实验将在亚音速和超声速轴对称射流中进行，以量化测量的准确性，探索改进系统以减少误差来源，并将技术扩展到同时测量多个点。这些测量结果将用于验证轴对称湍流的计算模型，并在可能的情况下对模型进行改进。此外，在资助期间，将改进一种称为平面多普勒测速（PDV）的技术，该技术允许在二维场中测量多个速度分量。在FARRS和PDV的成功开发之后，将在更复杂的流动中进行测量，以研究可压缩湍流（即边界层和激波边界层相互作用）和流场，这是罗格斯大学目前由其他机构资助的（超音速横流中的横向射流，弱电离超音速流动，以及与热喷涂过程相关的气体动力学）。为了这项研究计划，已经与工业界（Innovative Scientific Solutions Inc.和Spectra Physics）和政府实验室（即莱特实验室）建立了合作关系。

ABSTRACT Proposal Number: CTS-9733388 Principal Investigator: Elliott The Study of Turbulence and Compressible Flows Using Molecular Filter Based Diagnostics The primary goal of this CAREER Award is to support the development of a non-intrusive flow diagnostic technique termed Filtered Angularly Resolved Rayleigh Scattering (FARRS), which will simultaneously measure instantaneous velocity, density, temperature, and pressure. This technique measures the scattering from a point measurement volume from a focused beam of a ND:YAG pulsed laser which interrogates the flow. An anamorphic optical system is used to separately record rays which view the Rayleigh scattered signal at different angles. The image recorded onto an intensified CCD camera results in an intensity verses viewing angle profile. By placing an iodine filter in front of the camera and tuning the laser to an absorption line of iodine, the scattered intensity verses viewing angle profile recorded on the CCD changes shape depending on the velocity, density, temperature, and pressure of the flow. The profile for each instantaneous (10 ns) laser pulse can then be used to compute the fluid properties. Experiments will be made in subsonic and supersonic axisymmetric jets to quantify the accuracy of the measurements, explore improvements to the system to reduce sources of error, and extend the technique to measure multiple points simultaneously. These measurements will be used to verify computational turbulence models of the axisymmetric 'et and improvements will 'II be made to the models when possible. Also during the funding period, improvements will be made to a technique termed Planar Doppler Velocimetry (PDV) which allows the measurement of multiple velocity components in a two dimensional field. Following success of the development of FARRS and PDV, measurements will be made in more complex flows to study compressible turbulence (i.e. boundary layers, and shock boundary layer interactions) and flowfields which are currently being funded at Rutgers by other agencies (a transverse jet in a supersonic cross flow, weakly ionized supersonic flows, and the gas dynamics associated with thermal spray processes). Collaborations have been set up with industry (Innovative Scientific Solutions Inc. and Spectra Physics) and government laboratories (i.e. Wright Laboratory) for this research plan.