title: Passive optical diagnostics of combustion flows.
abstract: A passive ir detection method based on the monochromatic radiative transfer equation is proposed to probe both a homogeneous and a nonhomogeneous medium for the simultaneous determination of temperature and species concentrations. The problem of determining these thermodynamic variables and their sensitivities is solved by a ratio technique for a homogeneous medium. The solution requires inversion of a linear matrix equation when there are more than one absorbing species at the observing frequencies. A generalized Abel inversion method utilizing multifrequency multiangle scannings is developed to solve for the nonhomogeneous 2-D distribution of these parameters. Two special cases which assume combinations of axisymmetric and asymmetric distributions of the unknown parameters are also treated.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wang