Numerical investigation of the collision of a vortex ring with a wavy sphere

Authors

  • Nguyen Van Luc*
  • Le Tuan Phuong Nam
  • Phan Toai Tuyn

Abstract

The numerical investigation of vortex dynamics resulting from the collision of a vortex ring with a wavy sphere of various wavenumbers (n) at a Reynolds number of 1000 was conducted using a developed remeshed vortex particle method. The influence of the wall’s wavenumber on vortex dynamic mechanisms, such as the primary vortex ring’s deformation, the boundary layer’s separation, and the formation, interaction, and reconnection of secondary and tertiary vortices, was analysed. When the primary ring collides with a smooth sphere (n=0), secondary and tertiary rings are formed, and their interaction with the primary ring is similar to that observed with a flat plate. In the case of the wavy sphere, the boundary layer separates from the wall’s hills more rapidly than from the valleys, leading to the boundary layer rolling up into the secondary vortex in a wavy pattern. The segments of the secondary vortex originating from the hills move around the primary ring, while those from the valleys convect upwards, forming incomplete vortex loops at n=5. However, at n=9, the reconnection of segments from the valleys results in the formation of a chain of small-scale rings. Furthermore, tertiary vortices are generated from the valleys due to the additional separation of the wall boundary layer induced by the secondary vortex segments in the valleys. These vortices dissipate rapidly at n=5, whereas reconnection occurs to form additional vortex loops at n=9.

Keywords:

fluid dynamics, vortex dynamics, vortex interactions

DOI:

https://doi.org/10.31276/VJSTE.2024.0056

Classification number

2.1, 2.3

Author Biographies

Nguyen Van Luc

Division of Computational Mechanics, Institute for Advanced Study in Technology, Ton Duc Thang University, 19 Nguyen Huu Tho Street, Tan Phong Ward, District 7, Ho Chi Minh City, Vietnam

Faculty of Civil Engineering, Ton Duc Thang University, 19 Nguyen Huu Tho Street, Tan Phong Ward, District 7, Ho Chi Minh City, Vietnam

Le Tuan Phuong Nam

Institute of Engineering and Technology, Thu Dau Mot University, 6 Tran Van On Street, Phu Hoa Ward, Thu Dau Mot City, Binh Duong Province, Vietnam

Phan Toai Tuyn

Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam

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Published

2024-12-15

Received 28 May 2024; revised 17 June 2024; accepted 29 July 2024

How to Cite

Nguyen Van Luc, Le Tuan Phuong Nam, & Phan Toai Tuyn. (2024). Numerical investigation of the collision of a vortex ring with a wavy sphere. Vietnam Journal of Science, Technology and Engineering, 66(4), 57-63. https://doi.org/10.31276/VJSTE.2024.0056

Issue

Section

Physical Sciences