Laser Optics/Combustion Diagnostics.
Abstract
Coherent anti-Stokes Raman spectroscopy (CARS) instruments have been developed for simultaneous measurement of temperature and species concentrations in turbulent-diffusion, sooty hydrocarbon flames. Contour maps of average temperature, rms temperature, average concentration, and rms concentration have been obtained on a laboratory-scale burner. Simultaneous N2 and O2 measurements by the CARS technique were made with a dual-dye-laser setup. A combination of the laboratory CARS system and a laser-Doppler-velocimetry (LVD) system was completed and tested on a Busen-burner premixed flame. Measurements indicated that simultaneously obtained velocity and temperature data were Favre averaged due to density weighting of the seed particles. Temperature-velocity correlations were obtained and compared to literature values on similar burners obtained with a combined fine-wire thermocouple and LDV. Normal-gradient and counter-gradient transport were observed in the premixed flame. An environmentally hardened CARS system was developed and employed to measure temperatures in the near-wake recirculating-flow region of a bluff-body-stabilized diffusion flame. Time-averaged temperature profiles and probability distribution functions were obtained and interpreted in terms of flow-field characteristics. A comparison of temperature data obtained by means of the CARS technique and using three thermocouples of different design was made. This comparison indicated that the physical design of the thermocouple probe is important and may influence the flow and, thus, the temperature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1986
- Accession Number
- ADA173414
Entities
People
- G. L. Switzer
- L. P. Goss