An Uncertainty Propagations Analysis for an Infrared Band Model Technique for Combustion Gas Diagnostics

Abstract : The development of matrix equations for an uncertainty propagations analysis for the emission-absorption band model technique are described. The emission-absorption technique is used for the determination of local values of temperature and species concentration for measurements of radiance and transmittance on axisymmetric gas flows. The approach used depends on linearization of the original nonlinear system of equations comprising the solution to the radiative transfer problem for an emitting-absorbing source such as a turbojet or rocket engine exhaust plume. The resultant linear transformation matrix provides a means for determination of the variance- covariance matrix for inverted temperature and partial pressure, based on the experimentally determined variance-covariance matrix of the measured radiance and transmittances. The diagonal elements of the propagated variance-covariance matrix yield the square of the standard deviation of the temperature and partial pressure.