Effects of Solid Particle Properties on Cavitation Erosion in Solid-Water Mixtures

A systematic investigation has been carried out on cavitation erosion in solid-water mixtures using vibratory test facilities and some analytical devices. A mixture of distilled water and heterogeneous solid particles is used. It is shown in this work that solid particles play significant roles on acoustic cavitation erosion through two ways when present in liquids. They, aggravate the abrasive wear of materials owing to the effects of particle size, concentration, and hardness. In addition, they relieve the damage produced by the reduction of the collapse pressure of cavitation bubble because of the variation of the physical properties in mixtures. Total erosion is dependent on this governing factor.

Download Full-text

Cavitation erosion behavior of hydraulic concrete under high-speed flow

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-03-2021-2459 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Xin Wang ◽

Ting-Qiang Xie

Keyword(s):

Cavitation Bubble ◽

High Speed ◽

Cavitation Erosion ◽

Concrete Strength ◽

Bubble Collapse ◽

High Speed Flow ◽

Content Type ◽

Erosion Behavior ◽

Hydraulic Concrete ◽

Speed Flow

Purpose Cavitation erosion has always been a common technical problem in a hydraulic discharging structure. This paper aims to investigate the cavitation erosion behavior of hydraulic concrete under high-speed flow. Design/methodology/approach A high-speed and high-pressure venturi cavitation erosion generator was used to simulate the strong cavitation. The characteristics of hydrodynamic loads of cavitation bubble collapse zone, the failure characteristics and the erosion development process of concrete were investigated. The main influencing factors of cavitation erosion were discussed. Findings The collapse of the cavitation bubble group produced a high frequency, continuous and unsteady pulse load on the wall of concrete, which was more likely to cause fatigue failure of concrete materials. The cavitation action position and the main frequency of impact load were greatly affected by the downstream pressure. A power exponential relationship between cavitation load, cavitation erosion and flow speed was observed. With the increase of concrete strength, the degree of damage of cavitation erosion was approximately linearly reduced. Originality/value After cavitation erosion, a skeleton structure was formed by the accumulation of granular particles, and the relatively independent bulk structure of the surface differed from the flake structure formed after abrasion.

Download Full-text

Resistance of PVD Coatings to Erosive and Wear Processes: A Review

Coatings ◽

10.3390/coatings10100921 ◽

2020 ◽

Vol 10 (10) ◽

pp. 921

Author(s):

Alicja Krella

Keyword(s):

Wear Rate ◽

Solid Particle ◽

Coefficient Of Friction ◽

Cavitation Erosion ◽

Solid Particles ◽

Solid Particle Erosion ◽

Pvd Coatings ◽

Particle Erosion ◽

Tribological Tests ◽

Hydraulic Machines

Due to the increasing maintenance costs of hydraulic machines related to the damages caused by cavitation erosion and/or erosion of solid particles, as well as in tribological connections, surface protection of these components is very important. Up to now, numerous investigations of resistance of coatings, mainly nitride coatings, such as CrN, TiN, TiCN, (Ti,Cr)N coatings and multilayer TiN/Ti, ZrN/CrN and TN/(Ti,Al)N coatings, produced by physical vapor deposition (PVD) method using different techniques of deposition, such as magnetron sputtering, arc evaporation or ion plating, to cavitation erosion, solid particle erosion and wear have been made. The results of these investigations, degradation processes and main test devices used are presented in this paper. An effect of deposition of mono- and multi-layer PVD coatings on duration of incubation period, cumulative weight loss and erosion rate, as well as on wear rate and coefficient of friction in tribological tests is discussed. It is shown that PVD coating does not always provide extended incubation time and/or improved resistance to mentioned types of damage. The influence of structure, hardness, residence to plastic deformation and stresses in the coatings on erosion and wear resistance is discussed. In the case of cavitation erosion and solid particle erosion, a limit value of the ratio of hardness (H) to Young’s modulus (E) exists at which the best resistance is gained. In the case of tribological tests, the higher the H/E ratio and the lower the coefficient of friction, the lower the wear rate, but there are also many exceptions.

Download Full-text

The effect of surface‐active solutes on acoustic cavitation bubble populations

The Journal of the Acoustical Society of America ◽

10.1121/1.4777766 ◽

2003 ◽

Vol 114 (4) ◽

pp. 2386-2386

Author(s):

Judy Lee ◽

Sandra Kentish ◽

Muthupandian Ashokkumar ◽

Franz Grieser

Keyword(s):

Cavitation Bubble ◽

Acoustic Cavitation ◽

Surface Active ◽

Effect Of Surface

Download Full-text

Combined wear of slurry erosion, cavitation erosion, and corrosion on the simulated ship surface

Advances in Mechanical Engineering ◽

10.1177/1687814019834450 ◽

2019 ◽

Vol 11 (3) ◽

pp. 168781401983445 ◽

Cited By ~ 5

Author(s):

Liang Liang ◽

Youxia Pang ◽

Yong Tang ◽

Hao Zhang ◽

Hui Liu ◽

...

Keyword(s):

Cavitation Erosion ◽

Strong Support ◽

Wear Test ◽

Solid Particles ◽

Surface Material ◽

Slurry Erosion ◽

Wear Rates ◽

Ductile Materials ◽

Ship Hulls ◽

The Impact

The surface material of marine ship hulls suffers degradation by slurry erosion because of the impact of sands or solid particles in seawater. When the ship’s moving speed increases, pressure is changed suddenly and cavitation erosion will occur. Therefore, in the ocean, the corrosion of the surface material of the ship hulls is a combined damage in a slurry erosion and cavitation erosion states. An experimental device, for the combined wear, capable of simulating the above working conditions is designed and manufactured. A combined wear test of various materials (Q235, DH32, and NM360 steels) is conducted. The results show that cutting furrows of the slurry erosion, pinholes of the cavitation erosion, holes of electrochemical corrosion, and their combined effect increase the material wear rates and areas. Ductile materials of high strength have less slurry and cavitation damage, and more corrosion damage. For ductile materials of low strength, slurry and cavitation wear play an important role. When the slurry impact speed is increased, the wear degree of materials is also increased. This experimental setup for the combined wear provides a strong support for the development of wear-resistant materials for ship hulls and the structural optimization of ship hulls.

Download Full-text

Simultaneous Measurements of Flow Rates and Particle Concentrations in Heterogeneous Solid-Water Two-Phase Flows by Means of One Venturi.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.59.1087 ◽

1993 ◽

Vol 59 (560) ◽

pp. 1087-1093

Author(s):

Yasushige Hirata ◽

Masayuki Takano ◽

Tsutomu Narasaka

Keyword(s):

Two Phase Flows ◽

Two Phase ◽

Flow Rates ◽

Simultaneous Measurements ◽

Solid Water ◽

Heterogeneous Solid

Download Full-text

Modelling of material pitting from cavitation bubble collapse

Journal of Fluid Mechanics ◽

10.1017/jfm.2014.394 ◽

2014 ◽

Vol 755 ◽

pp. 142-175 ◽

Cited By ~ 83

Author(s):

Chao-Tsung Hsiao ◽

A. Jayaprakash ◽

A. Kapahi ◽

J.-K. Choi ◽

Georges L. Chahine

Keyword(s):

Cavitation Bubble ◽

Bubble Dynamics ◽

Numerical Approach ◽

Bubble Collapse ◽

Material Surface ◽

Collapse Pressure ◽

Flow Solver ◽

Incompressible Boundary ◽

The Impact ◽

Impulsive Pressure

AbstractMaterial pitting from cavitation bubble collapse is investigated numerically including two-way fluid–structure interaction (FSI). A hybrid numerical approach which links an incompressible boundary element method (BEM) solver and a compressible finite difference flow solver is applied to capture non-spherical bubble dynamics efficiently and accurately. The flow codes solve the fluid dynamics while intimately coupling the solution with a finite element structure code to enable simulation of the full FSI. During bubble collapse high impulsive pressures result from the impact of the bubble re-entrant jet on the material surface and from the collapse of the remaining bubble ring. A pit forms on the material surface when the impulsive pressure is large enough to result in high equivalent stresses exceeding the material yield stress. The results depend on bubble dynamics parameters such as the size of the bubble at its maximum volume, the bubble standoff distance from the material wall, and the pressure driving the bubble collapse. The effects of these parameters on the re-entrant jet, the following bubble ring collapse pressure, and the generated material pit characteristics are investigated.

Download Full-text