Development of Combustion Diagnostics and Application to Turbulent Combustion.
Abstract
Measurements with a tunable diode laser absorption system have been conducted in steady, fluctuating and sooting atmospheric-pressure flames produced in either a flat flame or a slot burner. Parameters measured include temperature, CO species concentration and CO spectroscopic parameters (line strengths and collision half widths). The measurements were made with two optical/tuning arrangements: by rapidly scanning the narrow-linewidth diode laser across individual vibration-rotation lines in the fundamental band of CO at 4.6 microns to record fully-resolved absorption line profiles in times as short as 100 microseconds; and by fixing the laser wavelength at the absorption line center and recording the absorption in real time. A conventional microprobe sampling system has been used to monitor CO and CO2 concentrations to enable comparisons between laser-based and conventional probe-based measurements in steady flames; thermocouples have been used to allow comparisons with laser-based temperature measurements. Good agreement was found between the laser-based and probe based measurements of CO when the sampling probe was operated at low pressures, p < 8000 Pa (60 torr), but a substantial error in probe measurements, due to conversion of CO to CO2 interior to the probe, was observed at higher, more typical probe pressures. A tunable dye laser system for high-resolution absorption spectroscopy of combustion gases at visible and near-ultraviolet wavelengths has been developed, The system has been assembled and feasibility experiments involving measurement of sodium in a flat flame burner have been completed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1980
- Accession Number
- ADA095719
Entities
People
- C. T. Bowman
- Ronald Kenneth Hanson
Organizations
- Stanford University