Abstract
Experimental results on the shock structure of dual co-axial jets are presented. The effects of the geometric parameters of the inner nozzle, jet static pressure ratio (ratio of the exit plane static pressures of the inner and outer nozzles) and the ratio of outer to inner nozzle throat area on the shock structure were studied. A superimposed outer and inner jet structure was observed in the schlieren photographs. The inner flow is compressed by the outer flow resulting in the formation of a Mach disc and an exit shock. A parameter incorporating the effect of Mach number of the inner nozzle and jet static pressure ratio was found to correlate the observations regarding the Mach disc location.
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References
Abbett M (1971) Mach disc in underexpanded exhaust plumes. AIAA J 9:512–513
Abdel-Fattah AM (1988) Discrete tone emission from high-pressure ratio supersonic jets from convergent-divergent nozzles. AIAA J 26:283–291
Adamson TC Jr., Nicholls JA (1959) On the structure of jets from highly underexpanded nozzles into still air. J Aerospace sciences 26:16–24
Addy AL (1981) Effects of axisymmetric sonic nozzle geometry on Mach disk characteristics. AIAA J 19:121–122
Buckley FI Jr. (1975) Mach disk location in jets in co-flowing airstreams. AIAA J 13:105–106
Crist S, Sherman PM, Glass DR (1966) Study of the highly underexpanded sonic jet. AIAA J 4:68–71
Chuech SG, Lai MC, Faeth GM (1989) Structure of turbulent sonic underexpanded free jets. AIAA J 27:549–559
Darwell HM, Badham H (1963) Shock formation in conical nozzles. AIAA J 1:1932–1934
D'Attorre L, Harshbarger FC (1965) Parameters affecting the normal shock location in underexpanded gas jets. AIAA J 3:530–531
Davidor W, Penner SS (1971) Shock standoff distance and Mach-disk diameters in underexpanded sonic jets. AIAA J 9:1651–1653
Dosanjh DS, Yu JC, Abdelhamid AN (1971) Reduction of noise from supersonic jet flows. AIAA J 9:2346–2353
Fox JH (1974) On the structure of jet plumes. AIAA J 12:105–107
Love ES, Grigsby CE, Lee LP, Woodling MJ (1959) Experimental and theoretical studies of axisymmetric free jets. NACA TR-6
Narayanan AK, Damodaran KA (1994) Mach disk of dual co-axial axisymmetric jets. AIAA J 31:1343–1345
Sheeran WJ, Dosanjh DS (1968) Observations on jet flows from a two-dimensional, underexpanded, sonic nozzle. AIAA J 6:540–542
Wilcox DE, Weir A Jr., Nicholls JA, Dunlap R (1957) Location of Mach discs and diamonds in supersonic air jets. J Aeronautical Sciences 24:150–152
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Rao, T.V.R., Kumar, R.R. & Kurian, J. Near field shock structure of dual co-axial jets. Shock Waves 6, 361–366 (1996). https://doi.org/10.1007/BF02511326
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DOI: https://doi.org/10.1007/BF02511326