Self-similarity and helical symmetry of various vortex wakes

I. K. Kabardin*, R. F. Mikkelsen, I.V. Naumov, V. L. Okulov, J. N. Sørensen, C. M. Velte

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

The present work examines the local structure and downstream evolution of both longitudinal vortexes behind the vortex generators and the helical tip vortices generated by the rotating 3-bladed rotor. Both wakes flow with the strong longitudinal or helical vortices have been studied by stereo PIV measurements in a wind tunnel or a water flume accordingly. The vorticity field was calculated from the measured velocity fields. The downstream development of vortex local cores investigates by using self-similarity scaling arguments and local helical symmetry tests simultaneously. It was analyzed Batchelor’s vortex and 2-D vortex with a helical vortex to use a combined vortex model of the helical self-similarly for a comparison with the experimental data. The experimental study of the shape of both vortices was carried out to describe the downstream development of the expanding vortex core by the new combined vortex model based on the experimental observations triggered by previous studies of wakes behind vortex generators and rotors. It was established that the local helical symmetry with a simple correspondence between the axial and azimuthal velocity in the cores exists in all cross-sections along of both longitudinal and helical vortices. It is also found that the averaged vorticity profiles inside the core of both vortices are self-similar. This knowledge is important for the fundamental understanding of the vortex flows, as well as for the aspect of applications, for which parametric descriptions can be substantially reduced in terms of required time and cost by easing engineering models.
Original languageEnglish
Title of host publicationAIP Conference Proceedings
Number of pages8
Volume2027
PublisherAmerican Institute of Physics
Publication date2018
Article number030115
ISBN (Electronic)9780735417472
DOIs
Publication statusPublished - 2018
Event19th International Conference on the Methods of Aerophysical Research, ICMAR 2018 - Akademgorodok, Novosibirsk, Russian Federation
Duration: 13 Aug 201819 Aug 2018

Conference

Conference19th International Conference on the Methods of Aerophysical Research, ICMAR 2018
CountryRussian Federation
CityAkademgorodok, Novosibirsk
Period13/08/201819/08/2018
SeriesA I P Conference Proceedings Series
ISSN0094-243X

Cite this

Kabardin, I. K., Mikkelsen, R. F., Naumov, I. V., Okulov, V. L., Sørensen, J. N., & Velte, C. M. (2018). Self-similarity and helical symmetry of various vortex wakes. In AIP Conference Proceedings (Vol. 2027). [030115] American Institute of Physics. A I P Conference Proceedings Series https://doi.org/10.1063/1.5065209
Kabardin, I. K. ; Mikkelsen, R. F. ; Naumov, I.V. ; Okulov, V. L. ; Sørensen, J. N. ; Velte, C. M. / Self-similarity and helical symmetry of various vortex wakes. AIP Conference Proceedings. Vol. 2027 American Institute of Physics, 2018. (A I P Conference Proceedings Series).
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title = "Self-similarity and helical symmetry of various vortex wakes",
abstract = "The present work examines the local structure and downstream evolution of both longitudinal vortexes behind the vortex generators and the helical tip vortices generated by the rotating 3-bladed rotor. Both wakes flow with the strong longitudinal or helical vortices have been studied by stereo PIV measurements in a wind tunnel or a water flume accordingly. The vorticity field was calculated from the measured velocity fields. The downstream development of vortex local cores investigates by using self-similarity scaling arguments and local helical symmetry tests simultaneously. It was analyzed Batchelor’s vortex and 2-D vortex with a helical vortex to use a combined vortex model of the helical self-similarly for a comparison with the experimental data. The experimental study of the shape of both vortices was carried out to describe the downstream development of the expanding vortex core by the new combined vortex model based on the experimental observations triggered by previous studies of wakes behind vortex generators and rotors. It was established that the local helical symmetry with a simple correspondence between the axial and azimuthal velocity in the cores exists in all cross-sections along of both longitudinal and helical vortices. It is also found that the averaged vorticity profiles inside the core of both vortices are self-similar. This knowledge is important for the fundamental understanding of the vortex flows, as well as for the aspect of applications, for which parametric descriptions can be substantially reduced in terms of required time and cost by easing engineering models.",
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Kabardin, IK, Mikkelsen, RF, Naumov, IV, Okulov, VL, Sørensen, JN & Velte, CM 2018, Self-similarity and helical symmetry of various vortex wakes. in AIP Conference Proceedings. vol. 2027, 030115, American Institute of Physics, A I P Conference Proceedings Series, 19th International Conference on the Methods of Aerophysical Research, ICMAR 2018, Akademgorodok, Novosibirsk, Russian Federation, 13/08/2018. https://doi.org/10.1063/1.5065209

Self-similarity and helical symmetry of various vortex wakes. / Kabardin, I. K. ; Mikkelsen, R. F.; Naumov, I.V.; Okulov, V. L.; Sørensen, J. N.; Velte, C. M.

AIP Conference Proceedings. Vol. 2027 American Institute of Physics, 2018. 030115 (A I P Conference Proceedings Series).

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

TY - GEN

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AU - Kabardin, I. K.

AU - Mikkelsen, R. F.

AU - Naumov, I.V.

AU - Okulov, V. L.

AU - Sørensen, J. N.

AU - Velte, C. M.

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N2 - The present work examines the local structure and downstream evolution of both longitudinal vortexes behind the vortex generators and the helical tip vortices generated by the rotating 3-bladed rotor. Both wakes flow with the strong longitudinal or helical vortices have been studied by stereo PIV measurements in a wind tunnel or a water flume accordingly. The vorticity field was calculated from the measured velocity fields. The downstream development of vortex local cores investigates by using self-similarity scaling arguments and local helical symmetry tests simultaneously. It was analyzed Batchelor’s vortex and 2-D vortex with a helical vortex to use a combined vortex model of the helical self-similarly for a comparison with the experimental data. The experimental study of the shape of both vortices was carried out to describe the downstream development of the expanding vortex core by the new combined vortex model based on the experimental observations triggered by previous studies of wakes behind vortex generators and rotors. It was established that the local helical symmetry with a simple correspondence between the axial and azimuthal velocity in the cores exists in all cross-sections along of both longitudinal and helical vortices. It is also found that the averaged vorticity profiles inside the core of both vortices are self-similar. This knowledge is important for the fundamental understanding of the vortex flows, as well as for the aspect of applications, for which parametric descriptions can be substantially reduced in terms of required time and cost by easing engineering models.

AB - The present work examines the local structure and downstream evolution of both longitudinal vortexes behind the vortex generators and the helical tip vortices generated by the rotating 3-bladed rotor. Both wakes flow with the strong longitudinal or helical vortices have been studied by stereo PIV measurements in a wind tunnel or a water flume accordingly. The vorticity field was calculated from the measured velocity fields. The downstream development of vortex local cores investigates by using self-similarity scaling arguments and local helical symmetry tests simultaneously. It was analyzed Batchelor’s vortex and 2-D vortex with a helical vortex to use a combined vortex model of the helical self-similarly for a comparison with the experimental data. The experimental study of the shape of both vortices was carried out to describe the downstream development of the expanding vortex core by the new combined vortex model based on the experimental observations triggered by previous studies of wakes behind vortex generators and rotors. It was established that the local helical symmetry with a simple correspondence between the axial and azimuthal velocity in the cores exists in all cross-sections along of both longitudinal and helical vortices. It is also found that the averaged vorticity profiles inside the core of both vortices are self-similar. This knowledge is important for the fundamental understanding of the vortex flows, as well as for the aspect of applications, for which parametric descriptions can be substantially reduced in terms of required time and cost by easing engineering models.

U2 - 10.1063/1.5065209

DO - 10.1063/1.5065209

M3 - Article in proceedings

VL - 2027

BT - AIP Conference Proceedings

PB - American Institute of Physics

ER -

Kabardin IK, Mikkelsen RF, Naumov IV, Okulov VL, Sørensen JN, Velte CM. Self-similarity and helical symmetry of various vortex wakes. In AIP Conference Proceedings. Vol. 2027. American Institute of Physics. 2018. 030115. (A I P Conference Proceedings Series). https://doi.org/10.1063/1.5065209