If we want to analyze the flow over a cylinder placed in the center of a channel, due to the complete geometric symmetry, we can use periodic boundary conditions instead of simulating the entire geometry. However, when we examine the simulation, we notice that the vortices behind the cylinder do not shed simultaneously from the top and bottom of the cylinder. Instead, for example, a vortex first sheds from the top and then from the bottom.
Despite the axial symmetry and the expectation that the simulation should also be symmetric—because the purpose of an axially symmetric simulation is to observe all occurrences at the top as they occur at the bottom—why do the vortices shed alternately rather than in pairs? Can it be said that this type of simulation is incorrect if done with axial symmetry?
could you show some pictures of your flow problem and solution?
Axially symmetric simulation can be appropriate for analyzing vortex shedding in cylindrical flow, especially when the flow pattern remains consistent along the axis. However, it's crucial to ensure that the chosen simulation accurately represents the physical conditions and boundary conditions of the system under study. If the flow exhibits three-dimensional behavior or significant variations along the axis, a fully three-dimensional simulation might be necessary for more accurate results.
Vortex shedding analysis in cylindrical flow is a complex phenomenon that has been extensively studied in the field of fluid mechanics. The axial symmetry assumption in simulating vortex shedding from a cylindrical body has been a topic of interest and debate. While some studies have focused on the symmetric shedding of vortices (Hu & Morgans, 2022), others have delved into the oblique and parallel modes of vortex Williamson, 1989). The inclusion of axial flow has been found to affect the advection of vortex core thinning away from the point of closest interaction during the collision process (Radcliff et al., 2000).
Numerical simulations have proven to be effective in representing vortex shedding phenomena (Hu et al., 2020). The wake vortex shedding from a natural cylinder can exhibit both antisymmetric and symmetric patterns (Hu et al., 2020). Additionally, the vortex shedding mechanism can be influenced by factors such as the Reynolds number and the presence of lateral end plates (Liang & Duan, 2019). Studies have also shown that the vortex shedding frequency can vary depending on the geometry of the body, such as semi-conical piers compared to cylindrical piers (Aghaee-Shalmani & Hakimzadeh, 2022).
Lata Deso Deso
If we are simulating an axially symmetrical problem it means the essence of the problem is axisymmetric, but in this case while we know vortex shedding is not axisymmetric so to speak, They have a phase difference. WHY this simulation can be done as axymetric?
Onset of vortex shedding around a short cylinder
Cambridge University Press & Assessment
https://www.cambridge.org › core › journals › article › o...
by Y Yang · 2022 · Cited by 6 — Linear stability analyses based on the time-mean flow has been applied to understand the Hopf bifurcation past which vortex shedding happens.
Missing: Incorrect | Show results with: Incorrect
Onset of vortex shedding around a short cylinder
📷
arXiv
https://arxiv.org › pdf
by Y Yang · 2021 · Cited by 6 — This paper presents results of three-dimensional direct numerical simulations (DNS) and global linear stability analyses (LSA) of a viscous ...
- Badges
- Science topic