Joint PDFs of Scalar Quantities in Turbulent Diffusion Flames by Raman and Rayleigh Scattering

Abstract

Simultaneous time and space resolved measurements of CO2, O2, CO, N2, H2O mole fractions and temperature are performed by using Raman and Rayleigh scattering. The investigated system is a turbulent jet of CO injected into the coflowing hot exhaust of a lean CH4/N2/O2‐flame. Mean values, joint one‐point 6D‐pdfs and characteristic statistic quantities are determined. The results for mean values agree well with measurements from independent methods. Determined joint one‐point pdfs resemble more‐dimensional normal distributions. The pdfs are non‐symmetric in the reaction zone with positive or negative correlation coefficients for the reactants. This indicates that the low Damköhler number system under investigation is not diffusion controlled. A quantification for this is given by the calculation of correlation coefficients and turbulence intensities. The measurements are suitable to verify models for transport equations of pdfs in turbulent reacting flows at low Damköhler numbers.