New Polarized-Depolarized Measurement Capability Extends Use of Raman/Rayleigh Methods to More Flame Types

By Robert Barlow Allowing single-shot measurements of all major species in nonsooting flames of simple fuels, such as H2 and CH4, spontaneous Raman scattering has been a key CRF laser diagnostic technique for fundamental turbulent-combustion studies. However, laser-induced fluorescence from soot precursors tends to interfere significantly with Raman scattering signals—limiting this method’s utility. Such fluorescence…

Uncertainty Quantification in Chemical Systems with Reaction Mechanisms Employing Rate Rules

A team of researchers—Jens Prager, formerly at the CRF and presently at the engineering simulation software firm CD-adapco; Habib Najm and Khachik Sargsyan of the CRF; Cosmin Safta of Sandia’s Computer Sciences and Information Systems center; and William Pitz of Lawrence Livermore National Laboratory—have studied the impact of uncertainty of reaction-rate constants in chemical ignition…