Journal of Flow Visualization and Image Processing

ISSN for PRINT: 1065-3090

For Online Access

Best Paper Award Selection - Editorial Board Site

2004, Volume11

Issue 3

104 pages

DOI: 10.1615/JFlowVisImageProc.v11.i3

Issue price - $154.00

Kwon-Hee Lee
Department of Mechanical Engineering, Saga University, 1, Honjo, Saga 840-8502, Japan

Toshiaki Setoguchi
Department of Mechanical Engineering, Saga University, 1, Honjo, Saga 840-8502, Japan

Shigeru Matsuo
Department of Mechanical Engineering, Saga University, 1, Honjo, Saga 840-8502, Japan

Heuy-Dong Kim
School of Mechanical Engineering, Andong National University, 388, Songchun, Andong 760-749, Korea

The near-field structure of an underexpanded sonic dual coaxial jet issuing from the coaxial nozzles of four different geometries is visualized by using a shadowgraph optical method. Experiments are conducted to investigate the effects of the nozzle geometry, such as nozzle-lip thickness, secondary stream thickness, the nozzle pressure ratio, and swirling of the secondary stream on the characteristics of the primary underexpanded jet. The results show that the presence of secondary annular swirling stream causes the Mach disc to move more downstream and increases its diameter, while the diameter of the Mach disc decreases with the decrease in the nozzle-lip thickness. The secondary stream thickness has an influence on the location of an annular shock wave. However, the effect of the secondary stream on the characteristics of the underexpanded coaxial jet is strongly dependent on the pressure ratio of the inner primary jet.

DOI: 10.1615/JFlowVisImageProc.v11.i3.20 Download article, 16 pages

Article price - $35.00

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