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Author
Pitts, W. M. | Kashiwagi, T.
Title
Chemically Reacting Turbulent Flow. Final Report.
Coporate
National Bureau of Standards, Gaithersburg, MD
Sponsor
Air Force Office of Scientific Research, Washington, DC
Report
NBSIR 85-3299, March 1986, 37 p.
Distribution
Available from National Technical Information Service
Contract
AFOSR-ISSA-00012
Keywords
concentration fluctuations | concentration measurement | density effects | digital line camera | flow visualization | hot wire anemometry | rayleigh light scattering | reynolds number | velocity measurement
Abstract
This report summarizes the results of the first three years of a study on chemically reacting turbulent flow. This project has been jointly sponsored by the Air Force Office of Scientific Research and the National Bureau of Standards. The development of new diagnostics for variable density flows are described. These include Rayleigh light scattering for real-time, spatially-resolved concentration measurements, combined Rayleigh light scattering and hot-wire anemometry for simultaneous concentration and velocity measurements, and the development of a digital line camera which has allowed the concentration measurements to be made along a line. A study of heat transfer from heated cylinders is discussed which has generated a much improved correlation of experimental results. Shadowgraph visualization studies and centerline concentration measurements are described for variable density, axisymmetric turbulent jets overing jet to coflow density ratios of 0.14 to 37. These studies have also included a limited investigation of Reynolds number effects. The observed dependene of the mixing behavior on the density ratio and Re have led us to make new hypotheses concerning the nature of turbulent mixing. These hypotheses are shown to lead to qualitative predictions for the turbulent mixing which are in agreement with experimental findings.