Spatially Resolved Diagnostics Using Tunable Laser Absorption Spectroscopy

使用可调谐激光吸收光谱进行空间分辨诊断

• 批准号: 9215080
• 负责人: Philip Varghese
• 金额: $ 28.57万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9215080&HistoricalAwards=false
• 关键词: Spatially; Resolved; Diagnostics; Using; Tunable

Accurate measurements of temperature and species concentrations are important for characterization of high temperature gas flows, particularly in the area of combustion. Optical measurements are desirable since they are nonintrusive, nonperturbing, and the probe is not subject to a hostile environment. An absorption measurement provides a simple quantitative definition of the concentration of the absorbing specie along a line-of-sight; this is sometimes adequate information, but more often spatially resolved measurements are needed. In principle, two-dimensional temperature and concentration fields should be recoverable from a limited number of line-of-sight measurements using tomographic reconstruction, a method widely used in medical imaging. However, accurate quantitative reconstructions of temperature and concentration fields have been difficult to achieve because reconstruction algorithms are very sensitive to errors in the input data. The principal objective of this program is to measure temperature and concentration fields simultaneously using a reconstruction technique that exploits the tuning capability of infrared diode lasers to greatly reduce the sensitivity of the reconstruction methods to both random and systematic errors in the input data. The study will begin with reconstruction of radial temperature and concentration profiles (CO and CO2) in an axisymmetric flow, with subsequent extension of the procedures to reconstruction of two-dimensional sections of three-dimensional flows. The application of quantitative laser diagnostics to industrial scenarios has been hampered by the typical high cost of equipment involved and by the user sophistication required for achievement of quantitative results. Success with the these lower-cost, more user-friendly systems may well lead to wider usage in industry; the software and hardware developed should enable implementation of tomographic absorption diagnostic techniques in a wide variety of applications. Potentially, further development of this technology, with use of inexpensive laser diode sources, may allow instrumentation packages cheap and robust enough for use in in-plant process control systems.

温度和物种浓度的准确测量对于表征高温气流的表征很重要，尤其是在燃烧区域。 光学测量值是可取的，因为它们是非感知的，不受干扰的，并且该探针不受敌对的环境的影响。 吸收测量值简单地定义了沿视线的吸收规范浓度的浓度。这有时是足够的信息，但是通常需要在空间上解决的测量。 原则上，使用层析成像重建量的二维温度和浓度场应从有限数量的视线测量中回收，这是一种广泛用于医学成像的方法。 但是，由于重建算法对输入数据中的错误非常敏感，因此难以实现温度和浓度场的准确定量重建。 该程序的主要目的是使用重建技术同时测量温度和浓度场，该技术利用红外二极管激光器的调谐能力大大降低了重建方法对输入数据中随机和系统错误的敏感性。 该研究将从轴对称流中的径向温度和浓度曲线（CO和CO2）重建，随后扩展了三维流量的二维部分的程序。 典型的设备高成本以及实现定量结果所需的用户成熟度，将定量激光诊断的应用在工业场景中的应用受到阻碍。 这些较低的成本，更易于用的系统的成功很可能会导致行业更广泛的使用；开发的软件和硬件应能够在各种应用中实施层析成像吸收诊断技术。 有可能，通过使用廉价的激光二极管来源，该技术的进一步开发可能使仪器包装廉价且健壮，足以在植物过程控制系统中使用。