Large eddy simulation of micro vortex generator-controlled cavitation across multiple stages DOI

Chengqi Mou,

Bangxiang Che, Yuxuan Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(10)

Published: Oct. 1, 2024

Micro vortex generators (mVGs) control cavitation by altering the boundary layer flow structure. This study employs wall-adapting local eddy-viscosity large eddy simulation (WALE-LES) turbulence model combined with Zwart–Gerber–Belamri to conduct transient numerical simulations on National Advisory Committee for Aeronautics 0015 baseline hydrofoil and equipped mVGs under various numbers. The proper orthogonal decomposition method experiments verify accuracy consistency of these regarding cavity scale. elucidates mechanisms which suppress cloud at low numbers induce high Results indicate that maintain sheet characteristics numbers, reducing wall pressure fluctuations enhancing stability. During inception, mVG-induced leads early formation. In phase, modal energy distribution is more dispersed, while in inception concentrated significant dominant modes. Moreover, counter-rotating vortices generated mitigate separation, enhance leading-edge attachment stability, reduce high-frequency vibrations caused bubble shedding. significantly advances understanding accurately simulating revealing across different stages using WALE-LES model. findings demonstrate can effectively stabilize structures instabilities overall performance. These insights will have a impact design hydrofoils development strategies.

Language: Английский

An improved Eulerian-Lagrangian method combined with ductile material model for cavitation erosion assessment DOI
Ziyang Wang, Huaiyu Cheng, Xianwu Luo

et al.

Journal of Fluids Engineering, Journal Year: 2024, Volume and Issue: 147(5)

Published: Oct. 29, 2024

Abstract Cavitation erosion in hydraulic machinery constitutes a multifaceted, instantaneous physicochemical process resulting material wear and decreased efficiency. This paper employs an enhanced Eulerian–Lagrangian method to evaluate cavitation erosion. The captures erosive impact loads released by the nonspherical collapse of near-wall bubbles integrates them with one-dimensional ductile mode, capability lacking traditional homogeneous mixture methods. A classic axisymmetric nozzle test case is conducted under four different numbers (σ = 0.8, 0.9, 1.09, 1.6) validate reliability new approach. Qualitative quantitative analysis demonstrates that load distribution on lower upper walls aligns experimental measurements. Compared reference works, accurately predicts maximum position yields narrower area closer data. Moreover, relative error minimum incubation time at σ 0.9 wall calculated 4.67%, rate 36.6%. pivotal for further studying how various materials respond wear. Further reveals response patterns are similar conditions 1.09. In contrast, surface reduced 46.7%, nearly triples 1.6.

Language: Английский

Citations

8
Study of energy dissipation mechanisms and pressure pulsation spectrums in a vertical axial flow pumping station on the ultra-low head condition based on multiple analysis methods DOI

Shuaihao Lei,

Li Cheng,

Weigao Sheng

et al.

Energy, Journal Year: 2025, Volume and Issue: unknown, P. 135227 - 135227

Published: Feb. 1, 2025

Language: Английский

Citations

0
Investigation on flow instability in the hump region of the large vertical centrifugal pump under cavitation conditions based on proper orthogonal decomposition DOI
Gang Yang, Desheng Zhang, Xi Shen

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(11)

Published: Nov. 1, 2024

Complex flow patterns in a large vertical centrifugal pump (LVCP) when operating the hump region under cavitation conditions should deserve more attention. This research investigates interaction between and vortices LVCP from perspective of rigid vortex transport characteristics modal decomposition. The are pronounced cavitation. backflow at impeller inlet leading edge diffuser vanes can be found part-load conditions. Rigid analysis reveals low pressure generated pipe. fusion separation with surface shedding high trailing generates unique stall gradient. Under conditions, combination stretching, dilation (RVD), coriolis force, baroclinic torque (BT) cause further increase strength tail vortices. RVD BT caused by accelerate development vortices, diffuser, then generate gradient advance. Proper orthogonal decomposition indicates that occupy main energy pattern. pattern is superimposed variety different frequency characteristics, these show particular signal well below fn. interacts to induce easily, always dominate evolution.

Language: Английский

Citations

2
Large eddy simulation of micro vortex generator-controlled cavitation across multiple stages DOI

Chengqi Mou,

Bangxiang Che, Yuxuan Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(10)

Published: Oct. 1, 2024

Micro vortex generators (mVGs) control cavitation by altering the boundary layer flow structure. This study employs wall-adapting local eddy-viscosity large eddy simulation (WALE-LES) turbulence model combined with Zwart–Gerber–Belamri to conduct transient numerical simulations on National Advisory Committee for Aeronautics 0015 baseline hydrofoil and equipped mVGs under various numbers. The proper orthogonal decomposition method experiments verify accuracy consistency of these regarding cavity scale. elucidates mechanisms which suppress cloud at low numbers induce high Results indicate that maintain sheet characteristics numbers, reducing wall pressure fluctuations enhancing stability. During inception, mVG-induced leads early formation. In phase, modal energy distribution is more dispersed, while in inception concentrated significant dominant modes. Moreover, counter-rotating vortices generated mitigate separation, enhance leading-edge attachment stability, reduce high-frequency vibrations caused bubble shedding. significantly advances understanding accurately simulating revealing across different stages using WALE-LES model. findings demonstrate can effectively stabilize structures instabilities overall performance. These insights will have a impact design hydrofoils development strategies.

Language: Английский

Citations

2