- Author
- Pitts, W. M.
- Title
- Organized Large-Scale Structures and Scalar Dissipation in Axisymmetric Turbulent Jets. BFRL Fire Research Seminar. VHS Video.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
- Video, November 24, 1998,
- Keywords
- axisymmetric jets | turbulent jets | structures | rayleigh light scattering | line cameras | lasers | scalar dissipation
- Abstract
- An experimental technique employing Rayleigh light scattering and a unique line camera has been developed which allows real-time mass fraction measurements at 128 points along a laser beam passing through an isothermal axisymmetric jet of propane flowing into air. Measurements are made with high spatial (roughly 0.3 mm) and temporal (0.41 ms) resolution. By mildly smoothing the mass fraction data using wavelet analysis, it is possible to determine the radial component of scalar dissipation using direct differentiation along the measurement direction and the axial component by time differentiation and Taylor's hypothesis. During the presentation the experimental method and analysis procedures will be summarized. Representative mass fraction and scalar dissipation measurements will be used to demonstrate the importance of large-scale turbulent structures for mixing and to characterize scalar dissipation behavior.