Numerical research of water jet characteristics in underwater explosion based on compressible multicomponent flows

The dynamical process of underwater explosion bubble is a very complicated phenomenon with many facets needed to consider. After detonation, shock wave propagates in a very short time while the oscillation of bubble occurs in a long time. Bubble pulsation can cause serious damage for the structures nearby due to the whipping effect, bubble pulse or water jet impact in the collapse phase. This paper presents an application of Finite Element Method (FEM), namely Eulerian technique, to simulate the dynamical process of bubble and numerical results were verified by an experiment. This approach shows it's feasibility in simulating the bubble pulsation as well as the formation of water jet at the end of first contracting circle. Although numerical model was simplified by the boundary conditions, the success of this method is foundation for further study of bubble such as in predicting the damages of both nearby submerged structures as well as floating structures.

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PIV investigation of high Reynolds number submerged water jets at high-pressure ambient conditions

Experiments in Fluids ◽

10.1007/s00348-021-03167-x ◽

2021 ◽

Vol 62 (5) ◽

Author(s):

Sarah Jasper ◽

Jeanette Hussong ◽

Ralph Lindken

Keyword(s):

High Pressure ◽

Ambient Pressure ◽

Water Jet ◽

Deep Drilling ◽

Potential Core ◽

Operation Conditions ◽

Water Jets ◽

Cavitation Intensity ◽

Drilling Conditions ◽

Jet Characteristics

AbstractHigh-pressure water jets bear a great technological potential to enhance geothermal deep drilling. Compared to existing water cutting technologies, significantly different operation conditions are encountered under deep-drilling conditions, such as high ambient pressures. The fundamental fluid mechanics are significantly affected by those operation conditions. In this work we examine the influence of increasing ambient pressure of up to 12.0 MPa on the water jet characteristics under submerged drilling conditions. PIV measurements of the jet flow field at changing cavitation numbers reveal two characteristic regimes, which are distinguished by a critical cavitation number. In the cavitating regime, the jet decays considerably faster with increasing distance to the nozzle than in the non-cavitating regime. In addition to that, an increasing cavitation intensity shortens the potential core length of the water jet and increases the jet spreading angle and with this has a similar effect on the jet as increasing turbulence intensity in single-phase flows. Related to the decreasing kinetic energy of the jet in the cavitating regime, the resulting impact force of the water jet on the specimen surface decreases with increasing cavitation intensity. Our investigations indicate that a technology transfer from water jet cutting to submerged jet drilling requires adjustments of both nozzle geometries and jet operation conditions. Graphic abstract

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The Application of CEL Technique to Simulate the Behavior of an Underwater Explosion Bubble in the Vicinity of a Rigid Wall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.902.126 ◽

2020 ◽

Vol 902 ◽

pp. 126-139

Author(s):

Anh Tu Nguyen

Keyword(s):

Finite Element ◽

High Speed ◽

Bubble Dynamics ◽

Underwater Explosion ◽

Flow Simulation ◽

Rigid Wall ◽

Water Jet ◽

Complex Structures ◽

Explicit Finite Element ◽

Jet Impact

The dynamic process of an underwater explosion (UNDEX) is a complex phenomenon that involves several facets. After detonation, the shockwave radially propagates at a high speed and strikes nearby structures. Subsequently, bubble oscillation may substantially damage the structures because of the whipping effect, water jet impact, and bubble pulse. This paper presents an application of explicit finite element analyses to simulate the process of an UNDEX bubble in the vicinity of rigid wall, in which the coupled Eulerian-Lagrangian (CEL) approach was developed to overcome the difficulties regarding the classical finite element method (FEM), large deformations, and flow simulation of fluid and gas. The results demonstrate that the method is well suited to manage the UNDEX bubble problem and can be used to model the major features of the bubble dynamics. Furthermore, the behavior of an UNDEX bubble near a rigid wall was also examined in the present study, which showed that the migration of the bubble and the development of the water jet are influenced strongly by the standoff distance between the initial bubble position and the wall. This method can be used in future studies to examine UNDEX bubbles in the vicinity of deformable and complex structures.

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Numerical research on rock breaking by abrasive water jet-pick under confining pressure

International Journal of Rock Mechanics and Mining Sciences ◽

10.1016/j.ijrmms.2019.06.007 ◽

2019 ◽

Vol 120 ◽

pp. 41-49 ◽

Cited By ~ 6

Author(s):

Songyong Liu ◽

Yuming Cui ◽

Yueqiang Chen ◽

Chuwen Guo

Keyword(s):

Confining Pressure ◽

Rock Breaking ◽

Water Jet ◽

Abrasive Water Jet ◽

Numerical Research

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The Behavior of Bubble and Water Jet Induced by Underwater Explosion in a Rectangular Tube

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition ◽

10.2514/6.2011-187 ◽

2011 ◽

Cited By ~ 2

Author(s):

Taketoshi Koita ◽

Yujian Zhu ◽

Mingyu Sun

Keyword(s):

Underwater Explosion ◽

Water Jet ◽

Rectangular Tube

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Water jet characteristics in SS400 steel cutting process on surface roughness

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1034/1/012105 ◽

2021 ◽

Vol 1034 (1) ◽

pp. 012105

Author(s):

Mastiadi Tamjidillah ◽

Rachmat Subagyo ◽

Abdul Ghofur ◽

Herry Irawansyah

Keyword(s):

Surface Roughness ◽

Water Jet ◽

Cutting Process ◽

Jet Characteristics ◽

Steel Cutting

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An Experimental Investigation of a Heated Two-Dimensional Water Jet Discharge Into a Moving Stream

Journal of Heat Transfer ◽

10.1115/1.3450190 ◽

1974 ◽

Vol 96 (3) ◽

pp. 273-278 ◽

Cited By ~ 2

Author(s):

A. J. Patton ◽

F. L. Test ◽

W. M. Hagist

Keyword(s):

Experimental Investigation ◽

Water Jet ◽

Experimental Results ◽

Temperature Profiles ◽

Two Dimensional ◽

Water Stream ◽

Water Jets ◽

Temperature Decay ◽

Jet Trajectory ◽

Jet Characteristics

The experimental results are presented for a study of the behavior of heated and unheated two-dimensional water jets injected from the bottom of a moving water stream. The jet characteristics are described in terms of velocity and temperature profiles, velocity and temperature decay, jet width, jet trajectory, and jet turbulence. The conditions which favor the formation of an upstream thermal wedge are investigated.

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