Technical gazette, Vol. 30 No. 6, 2023.
Original scientific paper
https://doi.org/10.17559/TV-20230206000327
Prediction of the Vortex Evolution and Influence Analysis of Rough Bed in a Hydraulic Jump with the Omega-Liutex Method
Cong Trieu Tran
orcid.org/0000-0003-3637-4226
; Hanoi University of Civil Engineering, 55 Giai Phong, Hanoi, Vietnam
*
Cong Ty Trinh
orcid.org/0000-0002-2536-1561
; Hanoi University of Civil Engineering, 55 Giai Phong, Hanoi, Vietnam; College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China
* Corresponding author.
Abstract
The dissipation of energy downstream of hydropower projects is a significant issue. The hydraulic jump is exciting and widely applied in practice to dissipate energy. Many hydraulic jump characteristics have been studied, such as length of jump Lj and sequent flow depth y2. However, understanding the evolution of the vortex structure in the hydraulic jump shows a significant challenge. This study uses the RNG k- turbulence model to simulate hydraulic jumps on the rough bed. The Omega-Liutex method is compared with Q-criterion for capturing vortex structure in the hydraulic jump. The formation, development, and shedding of the vortex structure at the rough bed in the hydraulic jumper are analyzed. The vortex forms and rapidly reduces strength on the rough bed, resulting in fast dissipation of energy. At the rough block rows 2nd and 3rd, the vortex forms a vortex rope that moves downstream and then breaks. The vortex-shedding region represents a significant energy attenuation of the flow. Therefore, the rough bed dissipates kinetic energy well. Adding reliability to the vortex determined by the Liutex method, the vorticity transport equation is used to compare the vorticity distribution with the Liutex distribution. The results show a further comprehension of the hydraulic jump phenomenon and its energy dissipation.
Keywords
flow-3D; hydraulic Jump; omega-liutex method; vortex breakdown
Hrčak ID:
309225
URI
Publication date:
25.10.2023.
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