Modern Machinery (MM) Science Journal, June 2019

Modern Machinery (MM) Science Journal, June 2019

MULTIPHASE FLUID MODELS TO DEAL WITH FLUID FLOW DYNAMICS

Milada Kozubkova, Jana Jablonska, Marian Bojko, Lukas Dvorak, Maria Carnogurska
Keywords: cfd | fluid dynamics | density of compressible liquid | modulus of elasticity | multiphase fluid models

When dealing with dynamic issues, we often encounter problems of hydraulic shock (water hammer) and cavitation causing distortion of the surrounding material, destruction of material, accompanied by sounds and vibrations. These dynamic behavior of the liquids is due to the presence of gases in the liquid, especially air, vapor and possibly other gases in smaller quantities. The density of such a liquid (…)

TEST OF DOORS OBSTRUCTION DETECTION SENSOR

Lukas Dvorak, Kamil Fojtasek, Miroslav Krajca, Miroslav Bova
Keywords: Acid Pickling Lines | pneumatic valve | obstruction detection | safety | entrance door | train

In bus and train transport there are a number of requirements for the safety of the entrance door. For example there are requirements to provide obstruction detection within the door system. This should reverse the movement of the door should a passenger or some other obstruction restrict the doors operation. In case the door movement is realized by a pneumatic cylinder, obstruction detection can be ach (…)

METHODS OF INCREASING THE EFFICIENCY OF COGENERATION BASED ENERGY EQUIPMENT

Miroslav Rimar, Milan Abraham, Marcel Fedak, Andrii Kulikov, Peter Oravec, Jakub Vahovsky
Keywords: CAVE | energy | Simulation | ANSYS | cogeneration | efficiency

The evaluation of the performance characteristics of the device has a many type, depending on the monitored parameters. In the field of continuous measurements there is a quantum of measurement systems that allow long-term tracking and feedback. Part of the submitted contribution concerns the creation of a cogeneration unit model to monitor the flue gas pathways in relation to the production of pollutan (…)

TANDEM ROBOTIC FCAW WELDING

Marian Sigmund
Keywords: off-line laser sensor | tandemrobot welding | FCAW welding – welding method 138

This article describes robotic FCAW welding with using a tandem torch for welding bearing parts of mobile truck crane. Follow primary objective advantages of tandem welding compared to welding with a classical single wire. Mainly in light of welding speed, welding productivity with reference to resulting weld quality. In the article is firstly described the comparison of both robotic welding cells and a (…)

EFFECT OF CUTTING TOOL MICROGEOMETRY ON THE ALUMINIUM ALLOY MACHINING PROCESS

Tomas Zlamal, Ivan Mrkvica, Sarka Malotova, Ondrej Vortel, Tomas Vopat
Keywords: Build Up Edge | cutting edge | Microgeometry | Machining | Aluminium Alloys

The paper deals with the determination of the effect of controlled tool cutting edge preparation on AlCu4SiMg (EN AW - 2014) aluminium alloy machining process as well as on tool wear. To conduct the experiment, the authors have chosen longitudinal turning technology and cutting geometry of indexable cutting inserts marked CCGT 120408F-AL and proposed suitable cutting conditions. By controlled tool cutti (…)

VALVE CONTROL OF DRIVE WITH ROTARY HYDRAULIC MOTOR

Lumir Hruzik, Adam Burecek, Lukas Dvorak, Kamil Fojtasek, Peter Monka, Martin Vasina, Miroslav Bova
Keywords: hydraulics | mathematical model of drive | valve control | efficiencies of rotary hydraulic motor | drive characteristics

The paper describes the analysis of a valve control of a drive with a rotary hydraulic motor. The valve control is realized by a throttle valve. The individual drive characteristics are measured on the experimental device, i.e. the control and the torque-speed characteristics. The experimentally determined characteristics are compared to the theoretically calculated characteristics. Subsequently, the ef (…)

SELECTIVE LASER MELTING TECHNOLOGY AND INDIVIDUAL TI-6AL-4V IMPLANTS

Michal Ackermann, Jiri Safka, Lukas Capek, Jiri Bobek, Radomir Mendricky
Keywords: selective laser melting | SLM | additive manufacturing | individual implants | titanium alloys

This paper deals with the use of additive manufacturing from Ti-6Al-4V metal powder in the field of individual implants. Additive technologies such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM) enable the manufacturers to design the implants precisely with respect to the actual anatomy of each patient. In this paper, two major properties of the printed parts are studied. In the first (…)

METHODS OF TESTING THE MECHANICAL PROPERTIES OF ADDITIVELY MANUFACTURED COMPONENTS

Tatana Hrbackova, Thomas Simson, Jurgen Koch, Gerhard Wolf, Martina Koukolikova, Katerina Mertova
Keywords: tensile tests | additive manufacturing

One of the main advantages of additive manufacturing is the possibility of custom-made machine parts. Additive manufacturing enables the production of components with fine details that would be difficult to manufacture with conventional production. This, however, brings some difficulty in the case of the acquisition of conventional test specimens that might exceed the size of the product. Mechanical pro (…)

PERFORMANCE OF USING WASTE HOT WATER AS AN INNOVATIVE ENERGY SOURCE

Drazen Sarjanovic, Pavel Kovac, Dusan Jesic, Borislav Savkovic, Lubomir Soos
Keywords: modern technologies | environment | waste hot water | the innovative source of energy

The aim of this paper is to study the cost-effectiveness of using waste hot water as an energy source for heat pumps. The research was made in one part of the hotel complex on Kopaonik, in which the whole system is implemented with a heat pump and piping system for collecting hot water from showers and sinks (gray-water). Tap water that is collected in package (reservoirs) has a certain average temperat (…)

PROCESS FOR PRODUCING DIAMOND-LIKE CARBIDE COATINGS ON HARD ALLOYS

Alexander Shmatov, Lubomir Soos, Zdenko Krajny
Keywords: optimization | multicarbide coatings | thermochemical heat treatment

This article deals with the new surface hardening method for producing diamond-like multicomponent carbide coatings on tool hard alloys by high-temperature thermochemical heat treatment. The structure and properties of the obtained coatings are examined. For three-component systems for diffusion saturation of hard alloys, optimization of the powder mixtures was performed with respect to the wear resista (…)

PROCESSABILITY OF WC-CO POWDER MIXTURES USING SLM ADDITIVE TECHNOLOGY

David Bricin, Antonin Kriz
Keywords: phase analysis | internal defects | powder mixture properties | WC-Co cemented carbides | SLM technology

This contribution presents the findings from an experimental study which explored the possibility of processing WC-Co-based powders using selective laser melting (SLM) additive technology. Two commercially available WC-Co powder mixtures were studied. One is intended for thermally sprayed coatings and the other for isostatic pressing applications. Both were analysed using optical and scanning electron m (…)

EVALUATION OF COMBUSTION CHAMBER DESIGN USING CFD

Martin Lisy, Michal Spilacek, Marek Balas, Zdenek Skala
Keywords: emissions | biomass | gasification | combustion | cfd

This paper compares two designs of a gasification chamber for combustion of biomass from the view of combustion quality and the resulting gaseous emissions. To explain the difference in the emission values of the two different designs computational modeling is used to visualize basic processes important for combustion taking place in the combustion chamber, notably velocity field, temperature field and (…)

MINIMIZING TEMPERATURE AND TOOL WEAR ON ROCK CUTTING WITH NEGATIVE RAKE ANGLE

Yuni Hermawan, Rudy Soenoko, Yudy Surya Irawan, Sofyan Arief Setyabudi
Keywords: ductile iron | and tool wear | temperature | rock cutting | Rake angle

This research discusses the effect of negative rake angle, to the temperature and tool wear on rock cutting. The cutting process was conducted on marble rock material, without coolants and utilized tungsten carbide inserts with 0o, -5o, -10o, -15o, -25o, -30o and -40o rake angles; meanwhile, the feed rate, spindle speed and depth of cut were applied constantly. Temperature measurement used K-type thermo (…)

INFLUENCE OF SPD PROCESS ON LOW-CARBON STEEL MECHANICAL PROPERTIES

Stanislav Rusz, Ondrej Hilser, Vladislav Ochodek, Radek Cada, Jiri Svec, Pavel Szkandera
Keywords: Transport System | low-carbon steel | mechanical properties | severe plastic deformation | Steel strip

The paper analyses the influence of different values of the angle of the deformation zone in the forming tool on severe plastic deformation (SPD) process and on mechanical properties of resulting steel strip. Forming equipment using the severe plastic deformation (SPD) process and DRECE (Dual Rolling Equal Channel Extrusion) method built and installed in the laboratory for the development of new technol (…)