TOMOGRAPHIC ANALYSIS OF CO ABSORPTION IN A LOW-PRESSURE FLAME

摘要

Tomographic analysis is used to provide a correction to low-pressure stoichiometric premixed CH4/O-2 flame temperatures measured with tunable diode laser absorption spectroscopy employing CO two-line thermometry. It is shown that flame temperatures measured with line-of-sight-based two-line thermometry are always too low and that the correction to the observed temperature is a nonlinear function of the height above the burner surface. It is also shown that, at a given height in the flame, a constant temperature across the flame does not imply that vibrational populations are constant and that, at low pressures (<20 Torr), the flame spreads radially beyond the burner diameter and so may no longer be approximated by a one-dimensional model. [References: 19]