Simultaneous measurements of velocity and density in a turbulent nonpremixed flame

Simultaneous velocity and density measurements have been obtained throughout a turbulent nonpremixed flame under high Reynolds number conditions. The objective of the measurements was to obtain a better understanding of the structure of turbulent nonpremixed flames and the interaction between turbulence and combustion chemistry. The measurements were made with an apparatus which utilized both laser velocimetry and laser Rayleigh scattering. From these measurements it was shown previously that while the gradient diffusion submodel for the velocity-density correlations agreed with the radial correlation data, it was seldom consistent with the axial data. In the present paper the analysis of these data is extended to include information on flame intermittency, conditionally sampled results, and joint probability distributions of velocity and density. Comparisons made with results in nonreacting and analogous nonpremixed reacting jets show that both mean and fluctuating quantities and conditionally sampled results are dependent on flow conditions and the presence of combustion.