Simultaneous temperature and sensitive two-species concentration measurements by single-shot CARS
Abstract
A crossed-beam arrangement of a CARS apparatus incorporating nonresonant-background suppression is presently used to obtain simultaneously spatially and temporally resolved N2 and O2 mole-fraction and temperature measurements. The ability of the technique to measure two-dimensional pdf is demonstrated for the simple cases of an isothermal jet and a laminar premixed flame of air and ethylene. Fundamental difficulties are identified in the use of CARS for high-precision mole-fraction measurements, involving the creation of signals far from the geometrical focus, and turbulence and Stark-effect beam disruptions which cause large mole-fraction measurement errors.
- Publication:
-
Applied Optics
- Pub Date:
- April 1991
- DOI:
- 10.1364/AO.30.001263
- Bibcode:
- 1991ApOpt..30.1263P
- Keywords:
-
- Combustion Temperature;
- Laser Applications;
- Probability Density Functions;
- Raman Spectroscopy;
- Temperature Measurement;
- Ethylene;
- Flame Propagation;
- Neodymium Lasers;
- Nitrogen;
- Oxygen;
- Turbulent Jets;
- Instrumentation and Photography;
- FLAMES;
- COMBUSTION DIAGNOSTICS;
- TEMPERATURE;
- NITROGEN;
- COHERENT ANTI-STOKES RAMAN SCATTERING