Numerical simulation of cavitation-vortex interaction mechanism in an advanced rotational hydrodynamic cavitation reactor

Ultrasonics Sonochemistry, Journal Year: 2024, Volume and Issue: 105, P. 106849 - 106849

Published: March 14, 2024

Hydrodynamic cavitation (HC), a promising technology for enhancing processes, has shown distinct effectiveness and versatility in various chemical environmental applications. The recently developed advanced rotational hydrodynamic reactors (ARHCRs), employing generation units (CGUs) to induce cavitation, have demonstrated greater suitability industrial-scale applications than conventional devices. However, the intricate interplay between vortex along with its spatial-temporal evolution complex flow field of ARHCRs, remains inadequately elucidated. This study investigated interaction mechanism representative interaction-type ARHCR first time using "simplified strategy" Q-criterion. findings reveal that instability caused by CGUs leads helical flows, subsequently giving rise both sheet cavitation. Subsequently, utilizing Q-criterion, structures are identified be concentrated inside at CGU edges process mergence separation. These directly influence shape dimensions cavities, establishing Lastly, vorticity transport equation analysis uncovered stretching dilatation terms dominate process. Simultaneously, baroclinic term focuses on vapor-liquid interface, characterized significant alterations density pressure gradients. contribute better comprehension cavitation-vortex ARHCRs.

Language: Английский

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Dynamics of single cavitation bubble collapse jet under particle-wall synergy

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

Published: Oct. 1, 2024

The interaction between a particle and cavitation bubble significantly influences the erosive effect on wall surface of flow passage components in fluid machinery. This paper investigates dynamics single collapse jet under synergetic effects wall, using Kelvin impulse theory high-speed photographic experiments. A theoretical model to predict intensity direction at arbitrary locations near is constructed basis image method Weiss's theorem. accuracy verified by comparison with large number experimental results. mechanisms underlying relative contributions behavior are explored. key parameters also quantitatively analyzed, including positions particle, dimensionless radius. main conclusions as follows: (1) will cause deflection leading formation attraction zone. proposed effectively predicts spatial location this (2) There exists region which weak, there equilibrium point zero wall. position gradually approaches nonlinear manner increasing size quasi-linear decreasing particle–wall distance. (3) When same distance from changes toward vertical bubble–particle increases. Moreover, effective range particle's influence decreases decreases.

Language: Английский

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Investigations on cavitation flow and vorticity transport in a jet pump cavitation reactor with variable area ratios

Ultrasonics Sonochemistry, Journal Year: 2024, Volume and Issue: 108, P. 106964 - 106964

Published: June 22, 2024

Hydrodynamic cavitation (HC) has emerged as a promising technology for water disinfection. Interestingly, when subjected to specific pressures, jet pump reactors (JPCRs) exhibit effective treatment capabilities. This study investigated the flow and vorticty transport in JPCR with various area ratios by utilizing computational fluid dynamics. The results reveal that is more likely occur within ratio becomes smaller. While decreases, limit also leading reduced operational range JPCR. During inception stage, only few bubbles limited travel distances are generated at throat inlet. A stable layer developed between downstream wall during stage. In this phase, primary carried towards outlet. addition, it was found vortex stretching, compression expansion, baroclinic torque terms primarily influence vorticity equation context. work may provide reference value design of JPCRs treatment.

Language: Английский

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Numerical investigation on the liquid jet and the dynamics of the near-wall cavitation bubble under an acoustic field

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

Published: Nov. 1, 2024

The dynamics of the near-wall cavitation bubble in an acoustic field are fundamental forms cavitation, which has been associated with promising applications ultrasonic cleaning, chemical engineering, and food processing. However, potential physical mechanisms for cavitation-induced surface cleaning have not fully elucidated. ultrasonically driven numerically investigated by employing a compressible two-phase model implemented OpenFOAM. corresponding validation current containing was performed comparison experimental state-of-the-art theoretical results. Compared to state without field, can enhance collapse due its stretching effect, causing higher jet velocities shorter intervals. velocity increases 80.2%, time reduces 40.9% compared those γ = 1.1. In addition, effects stand-off distances (γ), pressure wave frequency (f), initial (p*) on dynamic behaviors were analyzed depth. results indicate that (e.g., loads at wall center maximal temperature) weakened increase (f) owing oscillation periods. Furthermore, maximum radius expansion decrease increasing f p*. 12.6% when 62.5% 20.5% p* 74%.

Language: Английский

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Investigation on the cylindrical bubble dynamics near a wall with an arched bulge

Journal of Hydrodynamics, Journal Year: 2024, Volume and Issue: 36(6), P. 1073 - 1082

Published: Dec. 1, 2024

Language: Английский

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