Coherent Structures Producing Machwaves Inside and Outside of the Supersonic Jet
Supersonic jets emit Machwaves which are rather regular ones. Previous investigations using visualizations and an optical microphone have revealed that these Machwaves are shock waves which are accompanying mixing layer structures travelling downstream at three preferred speeds. The experimental results could be approximated by very simple relations. Local measurements within the mixing layer are needed in order to find out the reason for these relations. Two particular doppler velocimeters have been used for doing such measurements. They have shown that a weak regular contribution to the essentielly random velocity fluctuations exists. All results obtained so far agree with a hypothesis which is based upon the idea that the regular contribution consists of a vortex pattern the movement and extent of which are governed by pressure waves.
KeywordsVortex Convection Propa Assure Smoke
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- 1.Oetel, H.; ISL-R 112/78.Google Scholar
- 2.Oertel, H.; pp. 266–275 in “Shock Tubes and Waves”; Proc. 12th Internat. Symp. on Shock Tubes and Waves; Jerusalem 1979, A. Lifshitz and J. Rom Ed., The Magnum Press, 1980.Google Scholar
- 3.Oertel, H.; Gatau, F.; George, A.; ISL-R 124/81.Google Scholar
- 4.Oertel, H.; Stoßrohre - Shock Tubes - Tubes à choc; Springer Verlag Wien - New York, 1966.Google Scholar
- 5.Smeets, G.; George, A.; ISL-R 109/80.Google Scholar
- 6.Oertel, H.; Gatau, F.; George, A.; ISL-R 110/82.Google Scholar
- 10.Corcos, G.M.; Univ.California, Berkeley, College of Eng. Rept. FM-79-2-a (1 979).Google Scholar