- Author
- Pitts, W. M.
- Title
- Effects of Global Density Ratio on the Centerline Mixing Behavior of Axisymmetric Turbulent Jets.
- Coporate
- National Institute of Standrds and Technology, Gaithersburg, MD
- Journal
- Experiments in Fluids, Vol. 11, 125-134, 1991
- Sponsor
- Air Force Office of Scientific Research, Washington, DC
- Contract
- AFOSR-ISSA-85-00012
- Keywords
- axisymmetric jets | turbulent jets | mixing | light scattering | density effects
- Abstract
- Measurements, utilizing Rayleigh light scattering, of time-averged concentration and unmixedness have been made along the centerlines of axisymmetric turbulent jets formed from six pairs of jet and ambient gases. Jet to ambient density ratios range from 0.14 to 5.11. Findings are compared with predictions of an approx. similarity analysis and with extensive previous literature measurements. It is shown that virtual origins for plots of inverse time-averaged concentration are strongly dependent on global density ratio. Unmixedness values first grow with increasing distance from the jet source and then achieve an asymptote. The flow distance required to reach this asymptote is a strong function of density ratio.