Disappearing vortex problem in vortex identification: Non-existence for selected criteria

0559947 - MÚ 2023 RIV US eng J - Journal Article
Kolář, Václav - Šístek, Jakub
Disappearing vortex problem in vortex identification: Non-existence for selected criteria.
Physics of Fluids. Roč. 34, č. 7 (2022), č. článku 071704. ISSN 1070-6631. E-ISSN 1089-7666
Grant - others:AV ČR(CZ) StrategieAV21/1
Program: StrategieAV
Institutional support: RVO:67985840
Keywords : vortex-identification methods * velocity-gradient tensor * decomposition methods
OECD category: Applied mathematics
Impact factor: 4.6, year: 2022
Method of publishing: Limited access
https://doi.org/10.1063/5.0099046

A discontinuous outcome of vortex-identification methods called the disappearing vortex problem (DVP) has been already found for the swirling strength criterion and the Rortex (later renamed as Liutex) method. Here, the opposite property reflecting the situation that the DVP cannot be found for any input data, that is, the non-existence of the DVP, is examined and proved valid for selected criteria based on the velocity-gradient tensor, including Q, lambda-2, and the triple decomposition method. For the Q-criterion and the triple decomposition method, it is done directly, whereas for lambda-2, it is shown using a proof by contradiction.
Permanent Link: https://hdl.handle.net/11104/0333068