Quantifying uncertainty in auto-compensating laser-induced incandescence parameters due to multiple nuisance parameters

Abstract

Auto-compensating laser-induced incandescence (AC-LII) can be used to infer the particle volume fraction of a soot-laden aerosol. This estimate requires detailed knowledge of multiple model parameters (nuisance parameters), such as the absorption function of soot, calibration coefficients, and laser sheet thickness, which are imperfectly known. This work considers how uncertainties in the nuisance parameters propagate into uncertainties present in soot volume fraction (SVF) and peak particle temperature estimates derived from LII data. The uncertainty of the nuisance parameters is examined and modeled using maximum entropy prior distributions. This uncertainty is then incorporated into the estimates of SVF and peak temperature through a rigorous marginalization technique. Marginalization is carried out using a Gaussian approximation, which is a fast alternative to techniques previously employed to compute uncertainties of AC-LII-derived quantities.Peer reviewed: YesNRC publication: Ye