Next Article in Journal
Constraints on the String T-Duality Propagator from the Hydrogen Atom
Previous Article in Journal
Identities Involving the Fourth-Order Linear Recurrence Sequence
Previous Article in Special Issue
Quasi-Periodic Oscillating Flows in a Channel with a Suddenly Expanded Section
Open AccessArticle

Shock Waves Asymmetry in a Symmetric Nozzle

Institute of Fluid Flow Machinery, Polish Academy of Sciences, 80-231 Gdansk, Poland
*
Author to whom correspondence should be addressed.
Symmetry 2019, 11(12), 1477; https://doi.org/10.3390/sym11121477
Received: 1 January 1970 / Revised: 28 November 2019 / Accepted: 2 December 2019 / Published: 4 December 2019
(This article belongs to the Special Issue Symmetry in Fluid Flow)
The results of the experimental research on the symmetry of supersonic flow in a symmetric convergent-divergent nozzle are presented. The investigations were focused on the fact that for some flow conditions the flow in a precisely symmetric nozzle becomes asymmetric. Starting from a specific value of Mach number, the flow becomes asymmetric in terms of shock wave λ-foot geometry on both sides of a symmetric nozzle. The evolution of the abovementioned asymmetry has been analysed for Mach number value ranging from M = 1.26 to M = 1.59 with the nozzle opening angle of up to 6.5° on each side. The presented results indicate that for the same flow parameters as Mach number and Reynolds number, and for the same geometry of the nozzle, different λ-foot size is formed at each wall. This unexpected behaviour is responsible for the flow asymmetry. Numerical simulations carried out earlier confirm the appearance of shock wave asymmetry. The side in which the asymmetry takes place is accidental, as the full symmetry of simulation mesh and experiment setup was secured. In numerical simulation the asymmetry follows always the same direction. In experiments the direction of asymmetry happens alternatively without any apparent reason. The explanation of the phenomena is provided in this paper.
Keywords: λ-foot; supersonic flow; flow asymmetry; shock waves topology λ-foot; supersonic flow; flow asymmetry; shock waves topology
MDPI and ACS Style

Telega, J.; Szwaba, R.; Doerffer, P. Shock Waves Asymmetry in a Symmetric Nozzle. Symmetry 2019, 11, 1477.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop