National Repository of Grey Literature 15 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Measurement and analysis of abrasive particles velocities in AWJ
Zeleňák, Michal ; Foldyna, Josef ; Martinec, Petr ; Cárach, J. ; Gurková, Lucie ; Nováková, Daria
Abrasive water jet (AWJ) is a progressive technology commonly used in many industrial applications. Potential of this technology is high and research in the field of optimal geometry design of an injection system has not been completed yet. New designs of the injection cutting head based on numerical simulation of the flow provide important information about processes occurring during the formation of AWJ. Detailed knowledge of velocities of abrasive particles during the abrasive water jet generation is vital for the verification of the numerical model. The aim of the experimental work was to test the applicability of the LIF (Laser Inducted Fluorescence) technique combined with the PTV (Particle Tracking Velocity) processing algorithms to analyze particle velocities at the output of the focusing tube. The combination of commonly used water pressures with abrasive mass flow rate was tested and the obtained results of abrasive particles velocities are presented in this paper.
Visualisation and quantitative analysis of flat continuous water jet structure
Ščučka, Jiří ; Zeleňák, Michal ; Foldyna, Josef ; Lehocká, D. ; Votavová, H.
The results of an experiment focused on the visualisation and structural analysis of flat continuous high-speed water jet used in descaling process are presented in this paper. The aim of the work was to test the applicability of the shadowgraph technique, combined with image processing and analysis methods, to visualise the water jet structure and analyse its main quantitative parameters. Volume percentage of water and air in the water jet structure, size of droplets and water bunches and other parameters were measured on digital images taken at various distances from the nozzle outlet. Knowledge of the water jet structure below the nozzle can facilitate an optimal setting of technological conditions of the water jetting with respect to the maximum disintegration effect on treated material. The described methods can also provide important information for development of new nozzles or entire water jetting tools for disintegration of materials.
Use of micro X-ray computed tomography for development and research into waterjets
Souček, Kamil ; Sitek, Libor ; Gurková, Lucie ; Georgiovská, Lucie
Non-destructive methods for analysis of various types of materials have been increasingly applied recently. One of these methods is the industrial micro X-ray computed tomography (CT). This paper presents an overview of experience in using the industrial micro X-ray computed tomography during research activities at the Institute of Geonics of the CAS. It discusses possibilities of the nondestructive visualization of the inner structures of a wide range of materials and objects, including examples of its use in research and development activities related to high speed waterjets.
CFD model of multiphase flow in the abrasive water jet tool
Říha, Zdeněk
The possibility of using CFD fluid flow modeling in area of tools with abrasive water jet is described in the paper. The correct function of such tool is based on proper setting of multiphase flow of water, air and solid particles in the inner space of the tool. The multiphase fluid flow numerical simulation can provide information which show relation between the geometry and the flow field. Then, this stable CFD model of multiphase flow creates key to design of the tool able to work with higher efficiency.
Abrasives and possibilities of increase in efficiency of abrasive waterjets
Martinec, Petr ; Sitek, Libor
The contribution focuses on the research into abrasive materials and possibilities of adjustment of their properties in order to increase the efficiency of the processes of machining and cutting with abrasive waterjets. Cutting ability of commonly available garnet concentrates and nontraditional products which are starting to access to the Czech market were tested and compared. In addition, entirely new garnet products which are not commercially available yet, recycled abrasives, abrasives with various sizes of grains and heat-affected abrasives or abrasives coated with a thin plastic layer were studied.
Erosion effects evaluation of pulsating water jet on brass EN 12164
Lehocká, D. ; Klich, Jiří ; Foldyna, Josef ; Hloch, Sergej ; Cárach, J.
The objective of this experiment is to verify an assumption that with decreasing value of feed rate, mass v material removal Δ of brass EN 12164 during cutting by pulsating water jet is increased, and to seek the mass erosion curve course depending on the change of feed rate v [mm·s-1]. The selected observed parameter was evaluated in two units of Δ [mg·s-1] and Δ [mg·mm-1]. Two mutually related experiments were carried out. In the pilot experiment, the curve originating at hydraulic power output of 15 kW was evaluated that was achieved in combination of nozzle diameter d [mm] and pressure p [MPa] - d/p [mm/MPa] = 1.0668/52; 1.3208/39; 1.6002/31. After the pilot experiment, another experiment followed in which a particular range of feed rate values v = 0.2 - 8 mm·s-1 was selected. This resulted in finding that different courses of erosion process exist for mass material removal expressed in the form of curve Δ [mg·s-1] and Δ [mg·mm-1], depending on feed rate v [mm·s-1].
Study of quality of nine aluminium alloys surfaces created using abrasive waterjet
Klichová, Dagmar ; Klich, Jiří ; Gurková, Lucie
The article focuses on the normalized method of measurement and evaluation of a surface texture created using the abrasive waterjet. It detects selected amplitude parameters of a roughness profile providing a form of a quantified description of properties of a surface topography. It studies the change in quality of machined surfaces created by the abrasive waterjet in nine selected materials of aluminium alloys when changing the traverse speed. Studied samples were measured by an optical profilometer MicroProf FRT and further analyzed with the SPIP software.
Study of surface topography of material eroded by pulsating water jet
Klich, Jiří ; Klichová, Dagmar
The paper focuses on the study of the effect of technological parameters on the topography of a surface eroded by a pulsating water jet. Parameters of the water pressure and the traversing velocity of the nozzle over the surface were observed. Effects of technological parameters were compared to the surface roughness parameters Ra, Rz, Rv, Rp, Rsk and Rku. The material tested was the aluminium alloy EN AW6060 T66. The surface was measured using an optical profilometer and further assessed using the confocal microscope based on a metallographic section.
Hardness and elasticity of abrasive particles measured by instrumented indentation
Hvizdoš, P. ; Zeleňák, Michal ; Hloch, Sergej
Basic mechanical properties of seven types (from seven different sites) of abrasive garnet particles used for water jet cutting were measured using the technique of instrumented indentation (also called depth sensing indentation or nanoindentation). Hardness and modulus of elasticity were evaluated and compared. All the abrasives had similar measured mechanical properties (hardness 20 – 24.16 GPa), the highest values were found for the Czech garnet.
Water jet 2015 - Research, Develompent, Applications
Sitek, Libor ; Klichová, Dagmar
The fourth international meeting of producers, users, designers and other public interested in the technology of high speed water jet. Forum for the exchange of knowledge, information and experiences in areas of research, development and application of the water jet (cutting, machining, repair of structures, cleaning, removal of coatings and layers, hydrodemolition, mining, abrasive materials, special applications of the water jet, high-pressure technique, safety aspects, etc.).

National Repository of Grey Literature : 15 records found   1 - 10next  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.