ABSTRACT CTS-9407126 SUNY - Stony Brook P.I.: Surya Raghu This proposal has the objective of determining the interdependence of conditioned scalar dissipation, production and turbulent advection in the passive mixing of a jet of gas with ambient air. The proposed experiments are based on the equation for the one-point probability density function of a conserved scalar quantity in a turbulent shear flow. All the quantities needed to determine a satisfactory balance of the terms in the pdf equation will be measured. Rayleigh light scattering technique will be employed to measure instantaneous concentration and a specially calibrated hot-wire will be used to obtain axial and radial velocity fluctuations in the jet. The experiments will be conducted at the National Institute of Standards and Technology (NIST). The results obtained from this work will aid us in better understanding of the scalar transport phenomenon in a turbulent shear flow which is of great technological relevance to a variety of industrial and environmental flow situations. The proposed measurements will also serve to check the accuracy of earlier data on conditioned dissipation, which were obtained in the absence of measurements of conditioned scalar production and advection and, therefore, could not be subjected to a balance of the pdf equation.
