Publication detail

Influence of swirl ratio on the onset of columnar vortices in the mixing part of swirl generator

ŠTEFAN, D. URBAN, O. RUDOLF, P.

English title

Influence of swirl ratio on the onset of columnar vortices in the mixing part of swirl generator

Type

conference paper

Language

en

Original abstract

The study presents analysis of conditions for the onset of columnar vortices in the mixing part of swirl generator. The simplified geometry, used for this analysis, is based on the physical model of the bladeless swirl generator developed by the research group from Brno University of Technology. This swirl generator was previously used for several studies of the spiral vortex structures generated in the diffuser part. The main aim for the current study is the mixing mechanism, which is realized in the part where the axial inflow meets the tangential one. Since there are no guide vanes or other driving geometry features, the mixing mechanism is realized randomly, is strongly time-dependent and its behavior is linked to the swirl ratio between the axial and tangential inflows. From previous studies, the appearance of vortical structures with columnar-like shape was identified. For the better understanding of this mixing mechanism, which may influence the flow downstream and consequently the generated vortex, the several swirl ratios of axial and tangential inflow were studied. The dynamic of vortices are extracted using A-f analysis and proper orthogonal decomposition. The results are based on the CFD simulation employing a hybrid RANS+LES turbulence models.

English abstract

The study presents analysis of conditions for the onset of columnar vortices in the mixing part of swirl generator. The simplified geometry, used for this analysis, is based on the physical model of the bladeless swirl generator developed by the research group from Brno University of Technology. This swirl generator was previously used for several studies of the spiral vortex structures generated in the diffuser part. The main aim for the current study is the mixing mechanism, which is realized in the part where the axial inflow meets the tangential one. Since there are no guide vanes or other driving geometry features, the mixing mechanism is realized randomly, is strongly time-dependent and its behavior is linked to the swirl ratio between the axial and tangential inflows. From previous studies, the appearance of vortical structures with columnar-like shape was identified. For the better understanding of this mixing mechanism, which may influence the flow downstream and consequently the generated vortex, the several swirl ratios of axial and tangential inflow were studied. The dynamic of vortices are extracted using A-f analysis and proper orthogonal decomposition. The results are based on the CFD simulation employing a hybrid RANS+LES turbulence models.

Keywords in English

swirling flow;vortices;CFD

Released

07.04.2025

Publisher

 Institute of Physics

ISSN

1755-1307

Book

IOP Conference Series: Earth and Environmental Science

Volume

1483

Number

1

Pages from–to

1–8

Pages count

8

BIBTEX


@inproceedings{BUT197631,
  author="David {Štefan} and Ondřej {Urban} and Pavel {Rudolf},
  title="Influence of swirl ratio on the onset of columnar vortices in the mixing part of swirl generator",
  booktitle="IOP Conference Series: Earth and Environmental Science",
  year="2025",
  volume="1483",
  number="1",
  month="April",
  pages="1--8",
  publisher=" Institute of Physics",
  issn="1755-1307"
}