No (257)
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257
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Properties and characteristics of recycled garnet abrasives for AWJ
Martinec, Petr; Hlaváček, Petr; Ruppenthalová, Lucie; Sitek, Libor
2017 - English
The use of recycled garnet abrasive from sludge after cutting materials is a current\nproblem. The behavior of individual garnet abrasives in the AWJ process depends\non the geological origin of the garnets, which also affects all the material\ncharacteristics of the garnet recyclate. The parameters of the BARTON HPX80 and\nGMA 80 abrasive inputs and their recycled products were compared: mineralogical\ntype, apparent density, granularity, grain shape and mineralogical purity,\nmicrohardness data and the degree of damage to the garnet grains. All individual\nparameters of abrasives and their recyclates are reflected in the index of cutting\nefficiency of abrasive. The effect of abrasive material properties on cuttability of\nabrasives is synergistic. The new parameters in the evaluation of abrasives are\nmicro-hardness (brittleness criterion), specific surface and pore size distribution\n(internal grain damage criterion).
Keywords:
garnet; abrasive water jet; recycled abrasives; index of cutting efficiency of abrasive; microhardnes
Available on request at various institutes of the ASCR
Properties and characteristics of recycled garnet abrasives for AWJ
The use of recycled garnet abrasive from sludge after cutting materials is a current\nproblem. The behavior of individual garnet abrasives in the AWJ process depends\non the geological origin of the ...
Effects of Water Jets on CNTs/concrete composite
Foldyna, Vladimír; Foldyna, Josef
2017 - English
Results of the resistance of carbon nanotubes concrete composite (CNTs/concrete\ncomposite) to the action of pulsating and continuous water jets are presented in\nthis paper. This work brings advanced results of fully hydrated CNTs/concrete\ncomposite (after 28 days) and it follows up the research of this composite\nhydrated 7 days. The experiments were focused at the determination of erosion\neffects of both types of water jets impinging the surface of reference (concrete) and\nCNTs/concrete composite samples. Erosion effects of water jets were evaluated in\nterms of material removal rate. Tests were performed at various operating\nparameters of continuous and pulsating water jets.
Keywords:
CNTs/concrete composite; continuous and pulsating water jet; material removal
Available on request at various institutes of the ASCR
Effects of Water Jets on CNTs/concrete composite
Results of the resistance of carbon nanotubes concrete composite (CNTs/concrete\ncomposite) to the action of pulsating and continuous water jets are presented in\nthis paper. This work brings advanced ...
Prospective of using pulsating water jet peening as a surface treatment process
Srivastava, M.; Hloch, Sergej; Tripathi, R.; Chattopadhyaya, S.; Dixit, A. R.; Foldyna, Josef; Hvizdoš, P.; Fides, M.; Adamčík, P.
2017 - English
This study focusses on exploring the effect of using Pulsating water jet technology\nas a surface treatment process. The AISI 304 plate samples were subjected to\nthe treatment process using circular nozzle at different levels of pressure and\nstand-off distance combination with variation of traverse speed. For evaluating\nthe effect of peening the surface residual stress was measured using the x-ray\ndiffraction technique. The results showed that the initial tensile residual stresses\non the surface were relieved and converted to compressive residual stress.\nThe present study shows that the new technology can be used as a potential\nsurface treatment method.
Keywords:
residual stress; water jet; peening
Available on request at various institutes of the ASCR
Prospective of using pulsating water jet peening as a surface treatment process
This study focusses on exploring the effect of using Pulsating water jet technology\nas a surface treatment process. The AISI 304 plate samples were subjected to\nthe treatment process using circular ...
Comprehensive geological characterization of URF Bukov – part II Geotechnical characterization.
Souček, Kamil; Vavro, Martin; Staš, Lubomír; Kaláb, Zdeněk; Koníček, Petr; Georgiovská, Lucie; Kaláb, Tomáš; Konečný, Pavel; Kolcun, Alexej; Králová, Lucie; Kubina, Lukáš; Lednická, Markéta; Malík, Josef; Martinec, Petr; Ptáček, Jiří; Vavro, Leona; Waclawik, Petr; Zajícová, Vendula
2017 - English
This final report was processed as a part of Radioactive Waste Repository Authority project Research support for safety evaluation of the deep repository, which is a part of the preparation for the deep repository of nuclear waste (further DR). The aims of the project were collection and interpretation of geological data, the creation of models and obtaining information necessary for evaluation of potential sites for DR emplacement regarding long-term safety. On the basis of public submitting act, a 4-year contract was signed with ÚJV Řež, a.s. and its subcontractors: Czech Geological Survey, Czech Technical University in Prague, Technical University in Liberec, Institute of Geonics of Czech Academy of Sciences, and companies Arcadis CZ, Progeo, Chemcomex Praha and Centre for Research Řež about providing research support for evaluation of long-term safety.
Keywords:
spent nuclear fuel; nuclear waste; behaviour of rock environment; radionuclide transport; safety of repository
Available on request at various institutes of the ASCR
Comprehensive geological characterization of URF Bukov – part II Geotechnical characterization.
This final report was processed as a part of Radioactive Waste Repository Authority project Research support for safety evaluation of the deep repository, which is a part of the preparation for the ...
Influence of inner geometry shapes of suspension nozzles on hydraulic power conditions and water velocity fields of jets
Zeleňák, Michal; Říha, Zdeněk
2017 - English
The aim of study was numerical simulation of water flow with absence of abrasive particles inside inner geometry of suspension nozzle. Shapes of cone - radius profiles in relation with change of hydraulic parameters were studied. Results of simulations are presented in report.
Keywords:
high-speed abrasive suspension jet; cutting; technology; flow modelling
Available at various institutes of the ASCR
Influence of inner geometry shapes of suspension nozzles on hydraulic power conditions and water velocity fields of jets
The aim of study was numerical simulation of water flow with absence of abrasive particles inside inner geometry of suspension nozzle. Shapes of cone - radius profiles in relation with change of ...
CFD simulation of a free surface jet of high pressure nozzle. Jet sloping 90° 85° and 75°
Říha, Zdeněk
2017 - English
The report contains CFD results and description of the two phase flow water and air. Water comes into the computational domain through the nozzle which creates water jet. The jet falls on the wall surface where flows along the surface plate in all directions (x,y mainly). The aim of the work is to show how the falling water flows on the wall surface with help of advanced CFD model. Three cases had been solved there with a various jets sloping to the bottom surface plate. The first case contains results with configuration of the geometry for the jet sloping 90o. Second case contains results with configuration of the geometry for the jet sloping 85o and third case contains results with configuration of the geometry for the jet sloping 75o, see enclosures 1, 2 and 3. Given calculation had been done as steady state calculations.
Keywords:
CDF model; free surface jet; high pressure nozzle
Available at various institutes of the ASCR
CFD simulation of a free surface jet of high pressure nozzle. Jet sloping 90° 85° and 75°
The report contains CFD results and description of the two phase flow water and air. Water comes into the computational domain through the nozzle which creates water jet. The jet falls on the wall ...
Applications of Mathematics. Special Issue - SNA ´17
Rozložník, Miroslav; Sysala, Stanislav
2017 - English
This isssue of Applications of Mathematics is devoted to the Seminar on Numerical Analysis 2017 (SNA’17) held in New Aula of the VŠB—Technical University of Ostrava, January 30–February 3, 2017, and organized by the Institute of Geonics of the Czech Academy of Sciences in collaboration with IT4Innovations National Supercomputing Centre. The history of Seminar on Numerical Analysis (SNA) goes back to 2003. In 2005–2015, SNA was organized annually by the Institute of Geonics and Institute of Computer Science of the Czech Academy of Sciences in cooperation with Charles University in Prague, Czech Technical University, and VŠB—Technical University\nof Ostrava. Since 2016, Seminar on Numerical Analysis is organized alternatively on a biannual basis with the EMS School in Applied Mathematics (ESSAM). The scope of the seminar ranges from mathematical modeling and simulation of challenging engineering problems, to methods of numerical mathematics, numerical linear algebra, and high performance computing. An important part of SNA has\nbeen devoted to its Winter School with several longer lectures or tutorials focused on selected topics within the scope of the meeting. This year part of the Winter School was also the course Parallel Linear Algebra organized within the French PRACE Advanced Training Centre Maison de la Simulation. SNA’17 was attended by 77 participants, who presented six invited Winter School lectures, 24 short communications, and several posters.
Keywords:
aplied mathematics; numerical analysis; mathematical modeling
Available at various institutes of the ASCR
Applications of Mathematics. Special Issue - SNA ´17
This isssue of Applications of Mathematics is devoted to the Seminar on Numerical Analysis 2017 (SNA’17) held in New Aula of the VŠB—Technical University of Ostrava, January 30–February 3, 2017, and ...
Abrasive water jet drilling of cooling holes in aeroengines: preliminary experimental study
Hlaváček, Petr; Zlámal, T.; Sitek, Libor; Georgiovská, Lucie
2017 - English
This paper addresses an experimental investigation on the feasibility of using\nabrasive water jet (AWJ) for the drilling of small-diameter holes in aeroengines\ncomponents. These components are sprayed with ceramic thermal barrier coating\n(TBC). The required holes are typically 0.5 to 1 mm in diameter with a drilling\nangle of 30 to 90 deg. The parameters of the AWJ were varied to study their effects\non both quantitative and qualitative hole drilling parameters.
Keywords:
abrasive water jet; drilling; thermal barrier coating
Available on request at various institutes of the ASCR
Abrasive water jet drilling of cooling holes in aeroengines: preliminary experimental study
This paper addresses an experimental investigation on the feasibility of using\nabrasive water jet (AWJ) for the drilling of small-diameter holes in aeroengines\ncomponents. These components are ...
Evaluation of quality of cut surfaces created by abrasive water jet according to swiss standard SN 214001
Klichová, Dagmar; Gurková, Lucie
2017 - English
The article focuses on the evaluation of the quality of cut surfaces created by\nan abrasive water jet (AWJ) according to the Swiss standard SN 214001 (2010).\nThe standard presents a quantified description of the texture of the cut. It defines\nnew parameters and methods of parameter measurements used in order to\ncategorize the cut surface in various quality levels Q. They are so far the most\ncommonly applied form of the qualitative description of the quality of the cut\nsurfaces created by the AWJ technology.
Keywords:
surface quality; abrasive water jet; standard parameters
Available on request at various institutes of the ASCR
Evaluation of quality of cut surfaces created by abrasive water jet according to swiss standard SN 214001
The article focuses on the evaluation of the quality of cut surfaces created by\nan abrasive water jet (AWJ) according to the Swiss standard SN 214001 (2010).\nThe standard presents a quantified ...
Erosion capability of ultra-high-speed continuous waterjet and pulsating waterjet: the comparison
Sitek, Libor; Hlaváček, Petr; Klichová, Dagmar; Trieb, F.; Pude, F.
2017 - English
Advantages and possibilities of continuous ultra-high-speed waterjets (with\npressures of 600 MPa and more) when cutting metals are well known to\nthe professional public both from scientific studies and from practice. In addition\nto efficiency increased as water pressure increases and reduced water\nconsumption, abrasive consumption can also be reduced in the case of abrasive\nwaterjet. Ultra-high-speed waterjet technology allows not only to cut metal sheets\nwith pure water, but also allows cutting of harder materials such as ceramics.\nDespite the initial suspicion and technical problems associated with the reliability\nand sealing of some hyperpressure elements, high-pressure devices generating\nwater pressures around 600 MPa are now commercially available. However, no\ncomparison has been made so far concerning the efficiency of these jets with\nacoustically modulated high-speed pulsating waterjets using relatively low\npressures and higher water flow rates when eroding metallic materials.\nThe article compares cuts made by pure ultra-high-speed waterjet generated at\nhyperpressures (from 500 to 800 MPa) with erosive capabilities of pulsating\nwaterjets generated on the contrary at water pressures in the order of tens of MPa\non three metallic materials (stainless steel, mild steel and copper) using the same\njet hydraulic power.
Keywords:
hyperpressure; hydraulic power; ultra-high-speed waterjet; pulsating waterjet
Available on request at various institutes of the ASCR
Erosion capability of ultra-high-speed continuous waterjet and pulsating waterjet: the comparison
Advantages and possibilities of continuous ultra-high-speed waterjets (with\npressures of 600 MPa and more) when cutting metals are well known to\nthe professional public both from scientific studies ...
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