Visualization Methods for the Study of Unsteady Non-Premixed Jet Flame Structure

摘要

Non intrusive optical techniques have gained prominence in the investigation of unsteady reacting flows. Various imaging diagnostics have been applied to the study of such flows, including schlieren photography, flame luminosity and laser light scattering. Comparisons of the applicability of the different techniques for visualizing various flame structures are difficult, since the diagnostics have been applied individually to different flowfields. In this communication, we report visualization of the instantaneous structure of a single unsteady non premixed jet flame obtained using four complementary techniques. The flame structure is visualized through spatially integrated, time resolved schlieren and flame luminosity records, and planar imaging of both the instantaneous OH distribution, using laser induced fluorescence, and Mie scattering from seed particles. Comparison of the information obtainable by the different techniques is presented, and the potential benefit of combining complementary diagnostics, which yield information on different structures in the flame is demonstrated. Combustion, Reacting flows, Turbulent mixing, Diagnostics, Reprints. (mjm)