Asymmetric vortex shedding in the wake of an abruptly expanding annular jet

Vanierschot, Maarten
Perçin, Mustafa
van Oudheusden, Bas W.
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Abstract: In this paper, the structure of the turbulent wake behind the inner tube of a suddenly expanding annular jet flow is studied. The flow field is measured using tomographic particle image velocimetry and analyzed using proper orthogonal decomposition (POD). It was found that both the instantaneous and time-averaged central wakes behind the inner pipe are highly asymmetric despite the axisymmetric structure of the geometry. This asymmetry is the result of a bifurcation at low Reynolds numbers which persists up to the turbulent regime. The asymmetry induces a pair of counter-rotating vortices in the jet which are aligned with the main flow direction. Moreover, the asymmetry also induces a highly dynamical flow field. Analyzing the flow structures using POD shows that the wake oscillates around the asymmetric equilibrium position at a very low Strouhal number in the order of 0.01. On top of this motion, the inner shear layer oscillates with Strouhal numbers in the range of 0.1-0.3. This oscillation causes an asymmetric shedding of vortices of the hairpin type in the inner shear layer. As such, a local asymmetric region of very intensive mixing is induced near the stagnation point. Graphical Abstract: [Figure not available: see fulltext.]
Experiments in Fluids


Predictors of tolerating violence against women: honor concerns and fundamentalist religious orientation
Ceylan-Batur, Suzan; Sakallı, Nuray; Gunaratne, Stephanie (2021-01-01)
© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.The present study examined the role of justification for violence (honor-based vs. non-honor-based conflict), honor concerns (feminine, masculine, family, moral integrity), and fundamentalist religious orientation in predicting tolerance to violence against women (VAW) in an honor culture, Turkey. Six hundred and one Turkish university students (437 female, 164 male; M age = 21.16) participated in...
Heavy Z′ bosons in the secluded U(1) ′ model at hadron colliders
Frank, Mariana; Selbuz, Levent; Turan, İsmail (2021-05-01)
© 2021, The Author(s).We study Z′ phenomenology at hadron colliders in an U(1) ′ extended MSSM. We choose a U(1) ′ model with a secluded sector, where the tension between the electroweak scale and developing a large enough mass for Z′ is resolved by incorporating three additional singlet superfields into the model. We perform a detailed analysis of the production, followed by decays, including into supersymmetric particles, of a Z′ boson with mass between 4 and 5.2 TeV, with particular emphasis on its possi...
Designing and implementing a STEM career maturity program for prospective counselors
Karahan, Engin; Kara, Ahmet; AKÇAY, AHMET OĞUZ (2021-12-01)
© 2021, The Author(s).Background: Although the importance of directing students to career options in Science, Technology, Engineering, and Mathematics (STEM) fields at early ages has been emphasized in the literature, it has not been clearly stated just who will play a role in this process and what kind of consultancy process will be followed. It is of great importance for prospective counselors, who are studying in the field of counseling, to master the career selection process, specifically for STEM, towa...
Co-adaptation in Context with Iranian, Russian and Turkish Policies on Syrian Complexity: The Emergence of the Astana Process
Çoban, Mehmet İlbey (2021-01-01)
© 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.This research is based on explaining the dynamics that led the Iran, Russia and Turkey to initiate Astana Process within the framework of the Syrian Civil War’s changing dynamics. The article intends to combine power politics with the “complexity” paradigm. Linear ontology is problematic in explaining the changing dynamics. On the other hand, the complexity paradigm explains non-linear processes derived from its ontological fou...
Design of a linear to circular polarization converter integrated into a concrete construction for radome applications
Öztürk, Murat; Sevim, Umur Korkut; Altlntaş, Olcay; Ünal, Emin; Akgöl, Oguzhan; Karaaslan, Muharrem; Sabah, Cumali (2021-01-01)
© 2021 The Author(s). Published by Cambridge University Press in association with the European Microwave Association.In this paper, we present a linear to circular polarization converter integrated in a concrete structure to eliminate signal transmission problem originated from the concrete buildings in microwave regime. Two polarization converter samples and a control specimen made by traditional concrete are designed and their signal transmission responses are compared experimentally. Axial ratio values w...
Citation Formats
M. Vanierschot, M. Perçin, and B. W. van Oudheusden, “Asymmetric vortex shedding in the wake of an abruptly expanding annular jet,” Experiments in Fluids, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: