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Wall pressure and external velocity field relation in over-expanded supersonic jets
Abstract : Truncated Ideal Contour nozzles operating at off-design conditions encounter off-axis loads whose exact origin remains unclear. While these loads are usually attributed to non-axisymmetric motion of the adaptation shock wave, the unsteady pressure field in the downstream separated region may also be of importance: as the distance from the nozzle's structural attachment increases, small wall pressure fluctuations can generate undesired torque. Experiments are conducted on a Truncated Ideal Contour nozzle operated at over-expanded conditions. The study investigates the unsteady characteristics of the pressure fluctuations in the downstream separation region, and their links with the downstream developing jet flow dynamics. The analysis of the pressure fluctuations inside the nozzle reveals the existence of highly organized structures, both in time and in the azimuthal direction. It is shown that these organized fluctuations dominate the pressure signals in the separation region and that they correspond to an azimuthal mode responsible for the side-load generation. Moreover, it is shown that these specific pressure modes have a clear signature in the exiting jet flow field. A discussion is given in the paper on the possible origins of these organized structures
Cited literature [52 references]
https://hal.archives-ouvertes.fr/hal-02339512
Contributor : Vincent Jaunet Connect in order to contact the contributor
Submitted on : Wednesday, October 30, 2019 - 2:33:55 PM
Last modification on : Wednesday, November 3, 2021 - 9:36:49 AM
Contributor : Vincent Jaunet Connect in order to contact the contributor
Submitted on : Wednesday, October 30, 2019 - 2:33:55 PM
Last modification on : Wednesday, November 3, 2021 - 9:36:49 AM
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