SBIR Phase II: High-Frequency Shearing Interferometer Emission Velocimeter (SIEVE) for High-Temperature Gas Diagnostics

这个小型企业创新研究二期项目将开发一种功能强大的高温气体光学诊断技术，与目前使用的任何技术都有根本不同。这种诊断是空间定位的，但完全不受干扰。对于热发光气体，它利用气体本身的光学发射。对于不太发光的气体，新方法也可以用于监测通过气流的激光束的折射效应。在任何一种实现中，从气体中发出的光被分离成两个分量，其强度差异仅是由于在流的扩展体积内的空间局部区域中选定尺度尺寸的波动。对于低频（10兆赫）现象，该方法已经被证明，目前正在其他项目下开发。第二阶段计划的目的是将该技术扩展到更高的频率，这将允许研究较小规模的现象和更快的流动，以及等离子体中的快波。第一阶段设计了高频探测头，研制了新型超高频仪器。这两种仪器的原型将在第二阶段制造和测试。高频局部光学测速仪将是一个有价值的诊断非常热的气体，如电弧，燃烧炉和工业等离子体处理室。它也将有助于详细研究流动气体中的小尺度现象，如风洞中的边界层和湍流尾迹。在未来，预计这种新仪器也可以用于过程控制应用。从事气体和等离子体研究的团体将是这种仪器的首批客户。

Rostler 9529856 This Small Business Innovation Research Phase II project will develop a powerful optical diagnostic for high temperature gases that is fundamentally different from any technique currently in use. This diagnostic is spatially localized but completely nonperturbing. For hot luminous gases it utilizes the optical emission from the gas itself. For less luminous gases, the new method can also be used by monitoring refractive effects on laser beams passed through the flow. In either realization, the light emerging from the gas is separated into two components whose intensity difference is due only to fluctuations of selected scale size in a spatially localized region within the extended volume of the flow. For low-frequency (10 MHz) phenomena, the method has already been demonstrated and is currently being developed under other programs. The purpose of this Phase II program is to extend the technique to much higher frequencies, which will allow study of smaller-scale phenomena and faster flows, as well as fast waves in plasmas. In Phase I a high-frequency detector head was designed and a new ultrahigh-frequency instrument was invented. Prototypes of both instruments will be fabricated and tested in Phase II. A high-frequency localized optical velocimeter would be a valuable diagnostic for very hot gases such as are found in arcs, combustion furnaces and industrial plasma processing chambers. It would also be useful for detailed studies of small-scale phenomena in flowing gases, such as boundary layers and turbulent wakes in wind tunnels. In the future, it is envisioned that this new instrument could also be used in process control applications. Groups conducting research on gases and plasmas would be the initial customers for such an instrument.