TY - CONF
T1 - Instantaneous dual-tracer PLIF measurements of molecular mixing in axisymmetric jets
AU - King, G. F.
AU - Lucht, R. P.
AU - Dutton, J. C.
N1 - Funding Information:
This research was supported by the National Science Foundation, Division of Chemical and Transport Systems, with Dr. R. L. Powell and Dr. R.E.A. Arndt as Contract Monitors, under Grant No. CTS 94 - 23280.
Publisher Copyright:
© 1997, American Institute of Aeronautics and Astronautics, Inc.
PY - 1997
Y1 - 1997
N2 - A dual-tracer PLIF technique for making instantaneous, quantitative measurements of molecularly mixed fluid fraction is presented and demonstrated in an axisymmetric jet in a mild co-flow. The two-camera, two-laser technique uses PLIF of nitric oxide (NO) seeded in a nitrogen jet to mark unmixed jet fluid fraction, while PLIF of acetone seeded into the low velocity air co-flow marks total co-flow fluid fraction. By combining data from these two simultaneous images, quantitative measurements of molecularly mixed jet fluid fraction can be made on a pixel-by-pixel basis, while the "resolution-free" nature of the technique allows simultaneous study of overall flowfield characteristics and large-structure behavior. By calculating the jet fluid mixing efficiency, regions of subresolution stirring can also be visualized. Instantaneous images and probability density functions, calculated at x/d, = 2 and 3.5, are presented for Rejet, = 1000, 10,000, and 50,000. For the fully turbulent (Rejet = 50,000) conditions, stirring at subresolution scales is detected primarily on the jet side of the mixing layer. This creates a hybrid PDF behavior (stationary on the jet side of the mixing layer, marching on the co-flow side) that is not shown by passive scalar methods at equivalent image resolution.
AB - A dual-tracer PLIF technique for making instantaneous, quantitative measurements of molecularly mixed fluid fraction is presented and demonstrated in an axisymmetric jet in a mild co-flow. The two-camera, two-laser technique uses PLIF of nitric oxide (NO) seeded in a nitrogen jet to mark unmixed jet fluid fraction, while PLIF of acetone seeded into the low velocity air co-flow marks total co-flow fluid fraction. By combining data from these two simultaneous images, quantitative measurements of molecularly mixed jet fluid fraction can be made on a pixel-by-pixel basis, while the "resolution-free" nature of the technique allows simultaneous study of overall flowfield characteristics and large-structure behavior. By calculating the jet fluid mixing efficiency, regions of subresolution stirring can also be visualized. Instantaneous images and probability density functions, calculated at x/d, = 2 and 3.5, are presented for Rejet, = 1000, 10,000, and 50,000. For the fully turbulent (Rejet = 50,000) conditions, stirring at subresolution scales is detected primarily on the jet side of the mixing layer. This creates a hybrid PDF behavior (stationary on the jet side of the mixing layer, marching on the co-flow side) that is not shown by passive scalar methods at equivalent image resolution.
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M3 - Paper
AN - SCOPUS:84983189367
T2 - 35th Aerospace Sciences Meeting and Exhibit, 1997
Y2 - 6 January 1997 through 9 January 1997
ER -