Operation of Water Jet System in a Sandstone Quarry and its Impact on Production

2013 ◽  
Vol 308 ◽  
pp. 19-24
Author(s):  
Roman Gryc ◽  
Libor M. Hlaváč ◽  
Milan Mikoláš ◽  
Vilém Mádr ◽  
Ivan Wolf ◽  
...  
Keyword(s):  
Pure Water ◽  
Water Jet ◽  
Basic Information ◽  
System Operation ◽  
Water Jets ◽  
Cutting System

The experiments with pure water jets were performed both in laboratory and in a quarry. The basic information about water jet system operation in quarry conditions has been acquired and some relations between data from a quarry and the laboratory ones have been determined. The efficiency of the cutting system in quarry conditions is considered and discussed.

Numerical Simulation of Pure Water Jet Machining of Al 6061-T6 With Experimental Validation

2019 ◽  
Author(s):  
Greg Pasken ◽  
Jianfeng Ma ◽  
Muhammad P. Jahan ◽  
Shuting Lei
Keyword(s):  
Pure Water ◽  
Water Jet ◽  
Experimental Results ◽  
Inlet Pressure ◽  
Orifice Diameter ◽  
Small Scale ◽  
Machining Parameters ◽  
Water Jets ◽  
Small Scales ◽  
Simulation Results

Abstract Pure water jets are not as effective as abrasive water jets for cutting hard materials at large scales. Pure water jets can have kerfs as small as 0.076 mm, which is approximately the width of a human hair. This allows for small detailed cuts on workpiece material [1]. Research into using pure water jet to machine aluminum at small scales is important, as this will allow small scale and precision machining of the work piece material. At micro scales, water jet cutting with typical abrasives is not possible because the abrasive particles are typically in the micron range which is around the size of the cut. At small scales a pure water jet is more effective than abrasive water jet machining, as special nanometer size abrasives would be needed at small scales. A pure water jet only needs the correct size orifice to conduct machining at the small scale. These are the reasons why this study uses a pure water jet to conduct small scale machining of aluminum. This study investigates the use of ABAQUS’s Smoothed Particle Hydrodynamics to simulate pure water jet machining of metals and compares the simulation results of a water jet machining of Al6061-T6 to experimental results using the same material. The simulation results compare favorably to experimental results with only 2.81% error in the width of the cut. The predictive FEM modeling is then conducted for other combinations of machining parameters (orifice diameter and inlet pressure). It is found that orifice diameter and inlet pressure have substantial influence on the width and depth of cut. The results of the study open new possibilities for machining metals using a pure water jet at the micrometer scale and at smaller scales.

Numerical Modeling of a Pure Water Jet Machining of Ti-6Al-4V and Al 6061-T6 Using ABAQUS and Smoothed Particle Hydrodynamics

2018 ◽  
Author(s):  
Gregory Pasken ◽  
J. Ma ◽  
M. McQuilling ◽  
Muhammad P. Jahan
Keyword(s):  
Pure Water ◽  
Water Jet ◽  
Damage Initiation ◽  
Al 6061 ◽  
Hard Materials ◽  
Nano Scale ◽  
Water Jets ◽  
Water Jet Cutting ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

Pure water jets are not as effective as abrasive water jets for cutting hard materials at large scales. However, for nano-scale cutting, water jet cutting with abrasives is not possible because the abrasive particles are typically in the micron range which is three orders of magnitude larger than sizes to be cut. A pure water jet at the nano-scale might be a viable option. To ensure that it is possible to cut metals using a pure water jet, simulations at millimeter scale are conducted before downscaling to nano-scale. These simulations, using the smooth particle hydrodynamics (SPH) feature of ABAQUS, are conducted using two plate materials, Al 6061 and Ti-6Al-4V, with identical plate dimensions. The water jet is simulated via SPH, while the plate is modeled using standard FE methods. The water velocity and nozzle diameter are chosen to match those commonly used by companies employing water jets. Both the Al 6061 and Ti-6Al-4V simulations achieve convergence. Simulation results for both materials show damage on the surface and material removal. The top layer is removed in both cases as well as damage initiation is observed on the next layer of elements. These numerical results suggest that it is possible to use a pure water jet to cut two different metals. This research lays the foundation to use a pure water jet to conduct nanomachining of hard materials.

scholarly journals A Short Note about the Impact Action of a Water Jet Stabilized by a Coaxial Air Stream in the Air and Underwater

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5015
Author(s):  
Josef Poláček ◽  
Irena Marie Hlaváčová ◽  
Martin Tyč
Keyword(s):  
Near Field ◽  
Pure Water ◽  
Air Flow ◽  
Relevant Literature ◽  
Short Note ◽  
Original Method ◽  
Water Jet ◽  
Impact Action ◽  
Dual Action ◽  
The Impact

A new original method, applying a coaxial protective airflow, was tested aiming to improve the pure water jet efficiency in surface layer removal or medium hard materials cutting or blasting. The dual action of the air flow is expected: the air co-flowing the water jet with approximately the same velocity should prevent the central jet from breaking up into tiny droplets in the near field, and simultaneously, it should support jet decomposition into big parts with enough destructive potential in the far-field. A brief survey of the relevant literature dealing with the water jet instability is presented, introducing four recognized breakup regimes. An original cutting head designed to generate a waterjet surrounded by protective coaxial air flow is introduced. The submitted device is supposed to operate within the first wind-induced regime. Two types of experiments, consisting of blasting limestone bricks placed either in the air or underwater, were realized. The depths of kerfs produced with different water pressures and air overpressures were evaluated. While no substantial positive effect was recognized in the air performance, the submerged blasting of the same material under similar conditions appeared to be promising.

scholarly journals Design and Simulation of Nozzle for Pure Water Jet Portable Cutting Tool

2019 ◽  
Vol 8 (12S2) ◽  
pp. 703-706
Keyword(s):  
Pressure Drop ◽  
Cross Sections ◽  
Pure Water ◽  
Water Jet ◽  
Element Analysis ◽  
Cutting Machine ◽  
Water Jet Cutting ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
The Impact

A pure water jet at subsonic speed provides an opportunity for application in cutting soft material with the advantage of not contaminating the workpiece. Inside the nozzle, water is flowing through various cross sections, which lead to pressure drop and loss of energy. This requires a nozzle with a design that causes minimum pressure drop. In this work, Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) were used to analyse the flow through five different nozzles. For each nozzle, the pressures of 10 MPa, 20 MPa and 30 MPa were applies at the inlet. For the inlet pressure of 10 MPa, the highest outlet velocity us 136.12 m/s at the pressure of 9.261 MPa. The impact pressure at stand distance of 0.5 mm and 1.0 mm were 8.26 MPa and 8.02 MPa, respectively. For this nozzle, the Factor of Safety for 10 MPa, 20 MPa and 30 MPa were 6.4, 3.2 and 2.961, respectively. The findings are relevant to the development of pure water jet cutting machine

scholarly journals Archerfish coordinate fin-maneuvers with their shots

2021 ◽  
pp. jeb.233718
Author(s):  
Peggy Gerullis ◽  
Caroline P. Reinel ◽  
Stefan Schuster
Keyword(s):  
Water Jet ◽  
Characteristic Sequence ◽  
Target Height ◽  
Pectoral Fins ◽  
Water Jets ◽  
Low Amplitude

Archerfish down a variety of aerial prey from a range of distances using water jets that they adjust to size and distance of their prey. We describe here that characteristic rapid fin maneuvers, most notably of the pectoral and pelvic fins, are precisely coordinated with the release of the jet. We discovered these maneuvers in two fish that had been trained to shoot from fixed positions at targets in different height, whose jets had been characterized in detail and who remained stable during their shots. Based on the findings in these individuals we examined shooting-associated fin-movement in 28 further archerfish of two species that could shoot from freely chosen positions at targets of different height. Slightly before onset of the water jet, at a time when the shooter remains stable, the pectoral fins of all shooters switched from asynchronous low-amplitude beating to a synchronized rapid forward flap. Onset and duration of the forward and subsequent backward flap were robust across all individuals and shooting angles but depended on target height. The pelvic fins are slowly adducted at the start of the jet and stop after its release. All other fins also showed a characteristic sequence of activation, some starting about 0.5 s before the shot. Our findings suggest that shooting-related fin-maneuvers are needed to stabilize the shooter and that they are an important component in the precise and powerful far-distance shooting in archerfish.

The Effect of Nozzle Type on Air Entrainment by Plunging Water Jets

2002 ◽  
Vol 37 (3) ◽  
pp. 599-612 ◽  
Author(s):  
Tamer Bagatur ◽  
Ahmet Baylar ◽  
Nusret Sekerdag
Keyword(s):  
Penetration Depth ◽  
Oxygen Transfer ◽  
Free Water ◽  
Air Entrainment ◽  
Water Jet ◽  
Transfer Efficiency ◽  
Entrainment Rate ◽  
Water Jets ◽  
Air Entrainment Rate ◽  
Oxygen Transfer Efficiency

Abstract In this study, for the plunging water jet aeration system using various inclined nozzle types, bubble penetration depth, air entrainment rate, water jet expansion, effect of water jet circumference at impact point, oxygen transfer coefficient and oxygen transfer efficiency which changed depending on the water jet velocity, were researched in an air-water system. Numerous studies were conducted with circular nozzles. The present study describes new experiments performed with different nozzle types. Three types of nozzles were examined, i.e., those with circular, ellipse and rectangle duct with rounded ends. Experimental results showed that water jets produced with ellipse and rectangle duct with rounded ends nozzles have very different flow characteristics, entrainment patterns on free water jet surface, and submerged water jet region within the receiving tank. Higher air entrainment rate and oxygen transfer efficiency was observed in the rectangle duct with rounded ends nozzle due to water jet expansion. Bubble penetration depth, however, is lower for the rectangle duct with rounded ends nozzle than for the other nozzles. The ellipse nozzle provided the highest bubble penetration depth. These results showed that it is appropriate to use ellipse nozzle in aeration of deep pool and rectangle duct with rounded ends nozzle in the applications where high bubble concentration is desirable.

An experimental and simulation study of the flow pattern characteristics of water jet impingements in boreholes

2021 ◽  
pp. 014459872110520
Author(s):  
Yabin Gao ◽  
Xin Xiang ◽  
Ziwen Li ◽  
Xiaoya Guo ◽  
Peizhuang Han
Keyword(s):  
High Speed ◽  
Impact Force ◽  
Jet Impingement ◽  
Flow Patterns ◽  
Water Jet ◽  
Solid Boundary ◽  
Force Model ◽  
Water Jets ◽  
Contact Surfaces ◽  
The Impact

Hydraulic slotting has become one of the most common technologies adopted to increase permeability in low permeability in coal field seams. There are many factors affecting the rock breaking effects of water jets, among which the impact force cannot be ignored. To study the influencing effects of contact surface shapes on jet flow patterns and impact force, this study carried out experiments involving water jet impingement planes and boreholes under different pressure conditions. The investigations included numerical simulations under solid boundary based on gas–liquid coupling models and indoor experiments under high-speed camera observations. The results indicated that when the water jets impinged on different contact surfaces, obvious reflection flow occurred, and the axial velocity had changed through three stages during the development process. Moreover, the shapes of the contact surfaces, along with the outlet pressure, were found to have impacts on the angles and velocities of the reflected flow. The relevant empirical formulas were summarized according to this study's simulation results. In addition, the flow patterns and shapes of the contact surfaces were observed to have influencing effects on the impact force. An impact force model was established in this study based on the empirical formula, and the model was verified using both the simulation and experimental results. It was confirmed that the proposed model could provide important references for the optimization of the technical parameters water jet systems, which could provide theoretical support for the further intelligent and efficient transformation of coal mine drilling water jet technology.

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