Mobile CARS - IRS Instrument for Simultaneous Spectroscopic Measurement of Multiple Properties in Gaseous Flows

• Main Authors: Bivolaru, D., Lee, J.W., Jones, S.B., Tedder, S., Danehy, P.M., Magnotti, G., Cutler, A.D.
• Format: Conference Proceeding
• Language: English
• Subjects: Instruments; Laboratories; Laser beams; Optical interferometry; Performance evaluation; Raman scattering; Rayleigh scattering; Spectroscopy; Temperature measurement; Test facilities
• ISSN: 0730-2010; 2158-1142
• DOI: 10.1109/ICIASF.2007.4380891

This paper describes a measurement system based on the dual-pump coherent anti-Stokes Raman spectroscopy (CARS) and interferometric Rayleigh scattering (IRS) methods. The IRS measurement is performed simultaneously with the CARS measurement using a common green laser beam as a narrow-band light source. The mobile CARS-IRS instrument is designed for the use both in laboratories as well as in ground-based combustion test facilities. Furthermore, it is designed to be easily transported between laboratory and test facility. It performs single-point spatially and temporally resolved simultaneous measurements of temperature, species mole fraction of N 2 , O 2 , and H 2 , and two-components of velocity. A mobile laser system can be placed inside or outside the test facility, while a beam receiving and monitoring system is placed near the measurement location. Measurements in a laboratory small-scale Mach 1.6 H 2 -air combustion-heated supersonic jet were performed to test the capability of the system. Final setup and pretests of a larger scale reacting jet are ongoing at NASA Langley Research Center's Direct Connect Supersonic Combustor Test Facility (DCSCTF).