Physics of cavitation near particles

Journal of Hydrodynamics, Journal Year: 2024, Volume and Issue: 36(1), P. 102 - 118

Published: Feb. 1, 2024

Language: Английский

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Research on cavitation bubble behaviors between a dual-particle pair

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(2)

Published: Feb. 1, 2024

The interactions between particle clusters and cavitation bubbles play an important role in several industrial applications, e.g., the abrasive erosion of hydraulic machinery, efficiency improvement ultrasonic cleaning, mineral flotation. This paper explores influence a dual-particle pair unequal sizes on bubble collapse dynamics based Kelvin impulse model high-speed photography. impact radius ratio (ranging from 1.0 to 3.0), defined as large-particle small-particle radius, interface deformation, jet, translational movement is analyzed. main findings are follows: (1) Weiss theorem can effectively predict asymmetric behaviors terms moving distance direction centroid during collapse; (2) key parameter affecting intensity impulse, well distance; (3) zero-Kelvin-impulse point always biased toward smaller pair.

Language: Английский

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Numerical investigations of the interactions between bubble induced shock waves and particle based on OpenFOAM

Journal of Hydrodynamics, Journal Year: 2024, Volume and Issue: 36(2), P. 355 - 362

Published: April 1, 2024

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 the jets and shock waves of a cavitation bubble collapsing between a wall and a particle

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(3)

Published: March 1, 2024

The simultaneous presence of particles and cavitation bubbles has a deleterious effect on the performance safety hydraulic machinery through generation jets shock waves. In present paper, mechanisms responsible for evolution waves from collapsing bubble situated between spherical particle wall are simulated using compressible two-phase flow solver. Specifically, effects position jet wave behavior qualitatively analyzed. simulations experiments reveal three typical cases behavior: toward wall, double jets, particle. Needle commonly generated by collisions interface. some cases, needle associated with high impact velocity. It is found that smaller distance higher pressure wall.

Language: Английский

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Primary resonance characteristics of a cylindrical bubble based on the multi-scale method

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(2)

Published: Feb. 1, 2024

This paper describes a primary resonance theoretical model for cylindrical bubble under acoustic excitation. Based on the multi-scale method, an analytical solution of bubble–wall equation with second-order accuracy is obtained and numerically verified. The oscillation characteristics in time domain frequency response oscillations are analyzed different amplitudes frequencies excitation equilibrium radius bubble. study yields following findings: (1) For bubbles, exists unstable regions. Nonlinear behaviors such as jumps, hysteresis, multivalued solutions may be widely present. (2) As amplitude increase, backbone amplitude–frequency curve bends to left region gradually expands. (3) When dimensionless less than 0.005 1.0 × 10−5 m, disappears.

Language: Английский

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Theoretical and experimental investigation of a bubble collapsing near an asymmetric hydrofoil

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(2)

Published: Feb. 1, 2024

In the present paper, restricted cavitation bubble dynamics near an asymmetric Joukowsky hydrofoil are investigated theoretically and experimentally. This investigation employs conformal transformation, image method, Kelvin impulse model, together with high-speed photographic experiments. The characteristics of collapse deformation wall movement analyzed qualitatively quantitatively, spatial distributions liquid velocity revealed by theoretical predictions. main conclusions include (1) deformations can be divided into three typical cases: penetrating (mostly occurs when γ<2 γ defined as bubble-hydrofoil dimensionless distance), triangular depression 2<γ<4), arc-shaped γ>4). (2) acting on is governed a point source sink, which dominant, inversely correlated distance, corresponds to experimental results. (3) exhibits different at tail, head, middle regions hydrofoil, angle remains basically unchanged in concave region hydrofoils (i.e., range 240°<θz<350° θz position angle).

Language: Английский

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Influence of a hemispherical bulge on a flat wall upon the collapse jet of cavitation bubbles

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(3)

Published: March 1, 2024

Uneven sections along a wall cause local flow deterioration and can result in severe cavitation erosion. This paper investigates the influence of hemispherical bulge on flat upon collapse dynamics bubble terms Kelvin impulse theory high-speed photography based Weiss theorem image method. The evolution characteristics morphology, field distribution, (in strength, direction, directional sensitivity) are analyzed for symmetric asymmetric configurations. results show that jet be divided into three scenarios: mainly induced by bulge, wall, broadly equivalent effects both. Additionally, as dimensionless distance between increases, range attraction zone initially subsequently decreases, ultimately converges to diameter bulge. maximum width reach 3.45 times radius Finally, spatial sensitivity direction is found significant near junction

Language: Английский

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A review of bubble collapse near particles

Deleted Journal, Journal Year: 2024, Volume and Issue: 1(2)

Published: March 28, 2024

Bubble–particle interactions are of great importance in cavitation bubble dynamics, especially the case silt-laden flow. In this paper, a review physical mechanisms involved collapse near particles is presented, with an emphasis on jet and shock wave phenomenon. First all, occurring close to flat wall introduced provide basis for understanding behavior boundaries. Then, aim revealing processes that occur during particles, followed by detailed discussion, plentiful examples, process (the inception, growth, collapse, rebound, final disappearance bubble) formation jets inception jet, counter double jets) waves (incident, reflected, jet-induced, jet-split waves).

Language: Английский

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Cavitation intensity prediction and optimization for a Venturi cavitation reactor using deep learning

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

Published: Nov. 1, 2024

The Venturi reactor, widely used in process intensification through hydrodynamic cavitation technology, has proven highly effective various chemical and environmental applications. intensity of a is primarily influenced by shape parameters such as the convergent angle (β1), throat diameter (dth), length (lth), divergent (β2). However, impact these on not been sufficiently clarified. In this study, structural optimization reactor was accomplished integrating deep neural networks with particle swarm optimization. Cavitation Intensity Prediction Network model, which combines artificial numerical simulation, to establish nonlinear relationship between intensity. Partial dependence plots individual conditional expectation were utilized clarify influence each parameter. findings reveal that optimal 2.76 times greater than original design. Reducing β1 resulted swift conversion static pressure into dynamic pressure, but it also caused an uneven distribution fluid velocity. To reduce unevenness allow reach its peak, advantageous for generation, lth should be extended. dth directly efficiency converting key factor determining β2 indirectly impacted modulating space available development. insights gained from study may provide valuable guidance designing Venturis

Language: Английский

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