4. évf. , 1. szám (2019)
Gépészeti tudományok – Épületgépészet
Traditional power plants still the dominating power source for all the major industries and powerdemanding facilities, the most crucial facility for the whole plant operations is the industrial boiler which generatessteam, heating energy or electrical power. Boilers generate energy by combustion. The improvement of combustion efficiency could g...reatly influence the energy consumption and will make the boiler more efficient and cleaner (less emissions), that’s why it is important to understand the combustion and thermal flow behaviours inside the boiler. Beside experimental testing, computational work nowadays becoming more and more important due to lower cost and acceptable accuracy with minimum error. With numerical calculations method, the computational model created by a Computational Fluid Dynamics (CFD) software could reduce a lot of trial and error on experimental work. In this paper utilizing the ANSYS FLUENT 19.1 software to make crate the combustion model. The ratio of air to fuel mixture, the equivalency factor, mass flow rate of the mixture, velocity, mass fractions of the mixture components (fuel and air) and their temperatures will serve as the input parameter while the exhaust gase component mass fraction, temperature, mass flow and velocity will be monitored.
Nowadays the importance of renewable energy is growing, and the utilization of the low wind energy potential is getting crucial. There are turbines with low and high tip speed ratio. Turbines with low tip speed ratio such as the Savonius wind turbine can generate adequate amount of torque at low wind velocities. These types of turbines are also... called drag machines. The geometry of the blade can greatly influence the efficiency of the device. With Computational Fluid Dynamics (CFD) method, several optimizations can be done before the production. In our paper the Savonius wind turbine blade geometry was based on the so-called Myring equation. The primary objective of this paper was to increase the power coefficient by modelling the effect of the wind on the turbine blade. For the sake of simplicity, a 2D cross-sectional area was investigated in the simulation with ANSYS CFX 19.1.
The motion (displacement) of the Euclidean space can be decomposed into translation and rotation. The two kinds of motion of the Euclidean space based on two structures of the Euclidean space: The first one is the topological structure, the second one is the idea of distance. The motion is such a (topological) map, that the distance of any two...points remains the same. The bounded and closed domain of the Euclidean space is taken as a model of the rigid body. The bounded and closed domain of the Euclidean space is also taken as a model of the deformable solid body. The map – i.e. the displacement field – of the deformable solid body is continuous, but is not (necessarily) motion; the size and the shape of body can change. The material has atomic-molecular structure. In compliance with it, the material can be comprehended as a discrete system. In this case the elements of the material, as an atom, molecule, grain, can be comprehended as either material point, or rigid body. In the first case the kinematical freedom is the translation, in the latter case the translation and the rotation. In the paper we analyse how the kinematical behaviour of the discrete and continuous mechanical system can be characterise by translation and rotation. In the discrete system the two motions are independent variable. At the same time they characterise the movement of the body different way. For instance homogeneous local translation gives the global translation, but the homogeneous local rotation does not give the global rotation. To realise global rotation in a discrete system on one hand global rotation of the position of the discrete elements, on the other hand homogeneous local rotations of the discrete elements in harmony with global rotation are required. In the continuous system the two kinds of movement cannot be interpreted: a point cannot rotate, a rotation of surrounding of a point or direction can be interpreted. The kinematical characteristics, as the displacement (practically this is equal to translation) of (neighbourhood of) point, the rotation of surrounding of that point and the rotation of a direction went through that point are not independent variables: the translation of a point determines the rotation of the surrounding of that point as well as the rotation of a direction went through that point. With accordance this statement the displacement (practically translation) (field) as the only kinematical variable can be interpreted in the continuous medium.
Nowadays, urban freight traffic is causing significant noise and air pollution, so it is in the focus of green logistics developments, both in technology and system organization. Based on experiences within city logistics, significant problems are caused by the so-called concentrated sets of delivery points, where there are several delivery poi...nts with heavy freight traffic in a relatively small area. Since the summer of 2015, we collected lots of data about stores of these delivery points to support the modelling and the simulation of the new green solutions for the examined city logistics systems. Based on our results we can say, there are significant savings in these systems, so it is worth to deal with developing new, gateway-concept-based and consolidation-based solutions.
The analysis of the visual language of the product demands deeper analysis of the user’s profile and built behavioral patterns. There is an existing group of factors that have relatively constant nature - gender differentiation, age differentiation, belongingness to specific group – social status, place in hierarchy, race, religion, people...with special needs, etc. The analysis of the visual language of the product can be done by analyzing the basic arsenal of the composition - the means of composing form shaping: scale –related to the correct size of the products and their components; proportions –associated with organizing the form plastical and visual order of the whole and its parts; contrast - related to the shape of the product, semantical or bounded to past experience; color –bounded to both formal characteristics and plasticity, as well as to contrast and its meaningful designation; plastic of the form - linked to the proportions and scale, which determines not only the structural and formal characteristics of the products, but also the meaningful reading of the forms. The analysis of the individual composite devices is demonstrated by Ingo Maurer’s lighting fixtures.
Grain refining is an important technological step for the nucleus growth of the melt, in order to increase the number of nuclei, to improve mechanical properties (tensile strength, yield strength, hardness, elongation), feeding conditions and to decrease the tendency of hot tearing and the degree of sintering.  The aim of the experiments...was the determination of the grain refining effects of titanium (Ti) addition in the form of AlTi5B1 master alloy to the examined alloys (AlSi7MgCu0.5 – AC 42 000, AlSi9Cu3Fe0.5 – 46 500; AlSi9Cu1 – AC 46 400). The results prove that the addition of small amount of master alloy has a favourable effect on the foundry practice.
LASER treatment widely used in material processing technologies. The annealing is not the typical application of the LASER treatment, but this is possible to apply in case of cold deformed metals. In the article a cold rolled EN AW 8006 aluminum sheet is annealed by LASER treatment. The microstructure of the annealed sheets is observed by optic...al microscopy. An existing cellular automata simulation of recrystallization process is modified to study the LASER annealing. The observed microstructure and the simulated results are compared to determine the further development of the developed automaton.
In this paper, the Römer-glass are assessed as indicator of the technology and design by using a comparative method. We identifed their designing technology methods and associated them with manufacturing centres. All of them made from green forest glass and produced in northwestern and central Europe from around 1000-1700 AD. The Römer glass...present dining traditions and habits in the middle ages, furthermore like a personal belongings can be associated with the presentation of social status or individual expression.
In this contribution is analysed the force component of final force (passive force) by peripheral milling operation. Therefore, the main parameters that had influence to independent variable were revolutions, back engagement of a cutting edge ae, working engagement of the cutting edge ap. The article deals with the issue of milling in material...AlMgSi0.5 (aluminium alloy). Specifically evaluates the force component with respect to change of revolutions (4000/min., 5000/min., 6000/min.), working engagement of the cutting edge ap (1 mm, 2 mm, 3 mm) and back engagement of a cutting edge ae (5 mm, 10 mm, 15 mm). The Alfaflex process fluid with 7% concentration was supplied in an amount of about cca 10 l/min.
Over the last decade, the number of researches has increased in the field of bonding technologies. Researchers attempt to improve surface adhesion properties by surface treatments. Adhesive bonding is one of these bonding techniques, where it is important to see what surfaces will be bonded. One such surface property is wetting, which can be im...proved by several types of surface treatment. In recent years, atmospheric pressure plasmas have appeared, with which research is ongoing on surface treatments. In our research, we will deal with the effects of plasma surface treatment at atmospheric pressure and its measurement. In addition, we summarize the theoretical background of adhesion, surface tension and surface treatment with atmospheric pressure plasma. Our goal is to improve adhesion properties and thus the adhesion quality.
In this paper the effect of LDPE content in PVC foams are examined on the structure of both the foam and the LDPE. We attempt to understand how LDPE content affects the structure of PVC in blends and how it changes the glass-transition (Tg). These parameters often provide important information related to the overall macromolecular structure of...the polymer blend. Thermal analytical techniques such as differential scanning calorimetry (DSC) often used to determine the structural transformation of samples. The effect of the miscibility and composition of the PVC/LDPE foam blends on the thermal stability were also investigated.
The volume stock removal from the workpiece during the EDM is one of the important parameters that characterize the productivity of the electro-erosion process itself. Therefore, in terms of the economic efficiency of the electro-erosion process, it is appropriate that the value of the MRR parameter is as high as possible. The paper describes t...he results of experimental research to identify the extent of influence of the physical properties of the workpiece material on the workpiece material removal rate at EDM. The experiments were carried out using an Aggregron Hyperspark 3 electro-erosion machine on selected tool steels. As a tool electrode material for experimental purposes, graphite with the designation EX-60 was chosen because of its practical advantages.
In this paper, the properties of CuZn28 brass raw material were presented. The 3D printed metal specimens are made from this material with different orientations. Their mechanical properties (tensile strength, yield strength) and elongation were investigated according to MSZ EN 6892-1: 2012 standard. The strength of the different printing direc...tions is analyzed and it is determined which printing direction is the most favourable. Finally, the effect of the different printing directions upon the structure of the material is studied.
Throughout our research we have made potassium-humate from brown coal of Dudar. With potassiumhumate and copper(II)-sulfate we made test sheets of linter cellulose fibers. The surface energy, surface wettability, CIE Lab color-coordinates changing, bending resistance and tensile strength of the produced test sheets has been examined. There was...no big difference in the different samples during surface energy and wettability testing. Examination of mechanical properties suggests that potassium-humate content increases bending resistance of the test sheets. The bending resistance of samples increased by 32%, 100% and 336% compared to the control test sheets while adding potassium-humate.
The X153CrMoV12 ledeburitic chromium steel characteristically has high abrasive wear resistance, due to their high carbon and high chromium contents with a large volume of carbides in the microstructure. This steel quality has high compression strength, excellent deep hardenability and toughness properties, dimensional stability during heat tre...atment, high resistance to softening at elevated temperatures. The higher hardness of cryogenic treated samples in comparison with conventional quenched samples mean lower quantity of retained austenite as at samples quenched to room temperature and tempered in similar condition. In the microstructure of samples were observed that the primary carbide did not dissolve at 1070°C and their net structure have not been changed during to heat treatment. During to tempering at high temperature the primary carbides have become more and more rounded. After low tempering temperature in martensite were observed some small rounded carbides also, increasing the tempering temperature the quantity of finely dispersed carbides increased, which result higher hardness. The important issues in heat treatment of this steels are the reduction or elimination of retained austenite due to cryogenic treatment.
Duplex stainless steels (DSS) gaining their excellent mechanical properties and corrosion resistance due to their austenitic-ferritic microstructure, ideally in the same amount. However, to keep this ideal phase ratio during arc welding is very difficult. Generally, the arc welding processes will result in more ferritic microstructure in the we...ld metal and in the heat affected zone, due to the rapid cooling. The ferritic microstructure can cause chromiumnitride precipitation, because the nitrogen solubility in ferrite phase is very low below 700 °C. These chromiumnitride precipitations can cause loss of corrosion resistance and mechanical properties. However, during subsequent reheating, the chromium-nitrides can dissolve and act as a secondary austenite nucleation site in the ferritic microstructure. In our research we welded DSS specimen autogenously, with tungsten inert gas welding using pure argon and 94 % argon + 6 % nitrogen as shielding gasses. In the first case the sub-sequent solid-state reheating caused 20 % increase in the austenite fraction of the weld metal but with the use of mixed shielding gas only 5 % increase.
Modelling the complex coupled thermomechanical and tribological contact of a dry friction clutch system between cast iron flywheel and scatter-wound hybrid composite clutch facing requires a thought through investigation of the friction material properties and behaviour. Challenges of the creation of a mechanical stiffness matrix for such a com...plex material are described in this paper along with simplification ideas and solutions.
In most of the developing countries, plastic polypropylene is not fully recycled and converted in-to use after it is once used. Sisal fiber is also widely available in different developing countries like Ethiopia. Adding this two materials and developing automotive interior part was taken as a primary motive for it reduces cost and is environme...ntally friendly. Thus, the main purpose of this research is to develop composite material from natural fibre (sisal fiber) reinforced with recycled plastic waste (polypropylene) for interior automobile accessories specifically for internal door trim panel application. This research examines effect of fiber length, fiber loading and chemical treatment of fiber on the physical and chemical properties of the sisal fiber reinforced polypropylene (SFRPP) composite material. The waste polypropylene and the treated and untreated sisal fiber with variable length and weight ratio (fiber/matrix ratio) were mixed. Flammability of sisal fiber reinforced Polypropylene (SFRPP) composites material was examined by a horizontal burning test according to ASTM D635 and chemical resistance of the sisal fibre reinforced PP composites was studied using ASTM D543 testing method. The result on the flammability test shows that treated fiber has lower burning rate than untreated fiber and decreases with increase in fiber length and fiber loading. The resistance of the composites to water has increased as the fiber length increases and decreased as the fiber loading increase. Generally, SFRPP composite is found to have better resistance to water than NaOH and H2SO4 and treating the fiber has brought considerable improvement on chemical resistance of the composite. Fiber loading and fiber length has positive and negative effect on the flammability of the SFRPP composite respectively.
The presence of inclusions such as oxides, carbides or refractory particles can be harmful to the mechanical and surface characteristics of castings. Inclusion-rich metals result in lower fluidity and feeding capability during casting. Nowadays, solid fluxes are widely used in foundries in order to reduce the inclusion content of aluminium melt...s. In this study, the effect of four different fluxes on the melt quality was studied. First, the inclusion content of the flux-treated melt, and then the properties of the fluxes (i.e. chemical composition and melting temperature) were examined.
As a result of stricter environmental and safety standards, vehicle manufacturers have to reduce the weight of the vehicles, because 10% weight loss cause 8-10% reduction of fuel consumption. To reduce car’s weight and increase safety, vehicle manufacturers use high-strength steels. Further weight reduction can be achieved by using correspond...ing bonding technology (soldering, sticking) and optimizing these technologies can increase the strength of the joints. According to literature research, the improvement of interface properties has a large effect on bonding technologies. In order to improve interface properties, we can use multiple surface treatments. In our research we investigate the effects of CO2 laser surface treatment on high strength steels, because CO2 lasers are often used in the vehicle industry. In order to detect the effect of surface treatment, we investigate the wettability of the treated and untreated steels. In our research we measure the surface tension of treated and untreated steels. Our main goal is to improve wettability properties thus the bonding technology. In our research we used DP 600 high strength steel sheet with the thickness of 1 mm. We cut the steel sheet to 25mm wide and 55mm long workpieces. Before the surface treatment, the workpieces had to be cleaned and degreased using methanol. We searched for parameters that do not cause any visible changes on the surfaces. Among the parameters of the treatment we were able to change the output power of the laser. We used contact angle measurement to examine the wettability.
To choose the proper material for agricultural machinery we tested several materials with abrasive cloth on the pin-on-plate test device. After having the pre-results, we launched more complex abrasive testing (slurry-pot) simulating more realistic mode with soils to investigate the abrasive wear mechanism and resistance of the selected up-to-d...ate polymeric structural materials. for this, we developed a modified slurry-pot test machine that ensures the comparability of the materials over a wide range of conditions. Through this device, several parameters could be controlled like speed, the soil particle’s hit angle on the tested surface.
There is a great concern about utilizing different waste materials all over the world. Stockpiling in landfills is not a final solution, therefore researchers try to find alternative methods to utilize these materials [1-5]. One potential area may be road construction. Fillers are one of the most important components of asphalt pavements. It ha...s a dual role. First of all, these fine grained mineral materials (d<0.063 mm) enhance the cohesion with bitumen. Second is to fill the gaps between the particles to produce more compact mixture . The aim of this research is to reveal the possibility of utilization of aluminum dross as a potential asphalt filler. This material, which is a by-product of aluminum casting process, is produced in large quantities year by year and its storage in landfills is not a proper solution. Therefore, there is an increasing demand to utilize this material. During the research material structural tests were made, which can characterize the samples (limestone powder, dross), and the cohesion between bitumen and filler can also reveal. Particle size distribution, BET specific surface area and porosity were investigated. Scanning electron micrographs were taken and oil adsorption test were also made.
DP steels were extensively used in the vehicles industry due to its extraordinary combined properties of strength, ductility, formability and weldability which contributed great significance in reducing strength to weight ratio and CO2 emission. High strength steel i.e. DP steels (3 different grades) were experimentally investigated and thermop...hysically simulated using Gleeble 3500 simulator to determine softening and hardening in heat affected zone. Samples were heated to different peak temperatures (1350 °C, 950 °C, 775 °C and 650 °C), two cooling time (t8.5/5 = 5 s and 30 s) and Rykalin 2D model were selected. The hardness and microstructure of the specimens were tested and analysed. For longer cooling time (t8.5/5= 30 s), we observed that softening occurs in all grade of investigated DP steels to all sub-regions. But for shorter cooling time i.e. t8.5/5= 5 s the softening is higher in intercritical HAZ compared to other sub-regions for all the types of DP steel with short cooling time (t8.5/5 = 5 s). However, the hardening zone in the CGHAZ occurs when Tmax is 1350 ºC for DP600, DP800 & DP1000 steels but it is more prominent in DP800 as compared to others two steel grade.
Gépészeti tudományok – Gépészet
According to, Thomas Heatherwick, who was an English architecture, ‘The biggest object is a building’.  Nature has phenomenal problem solving skills – ‘Nature knows it better’. It has an impact on us and on our subconscious.
The aim of the study is to analyse and visualize the accuracy of two parallel manipulators. The kinematics are calculated using vectors and the Newton method. The accuracy is calculated based on the actuator errors, visualization is done with color shading. Calculations was done using MATLAB
Additive and subtractive manufacturing of Acrylonitrile Butadiene Styrene (ABS) were employed for fabricating samples. The Additive manufacturing was represented through 3D printing, whereas subtractive manufacturing carried out by Turning. Some developments have been applied for enhancing the performance of the 3D printer. Tribological measure...ments of the turned and 3D printed specimens have been achieved. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison of the tribological behaviour of the turned and 3D printed ABS polymer has been investigated.
The aim of this paper is to introduce some new numerical results on the magneto-thermomechanical interaction between heated viscous incompressible magnetic nanofluid and a cold wall in the presence of a spatially varying magnetic field. The governing nonlinear boundary layer equations are converted into coupled nonlinear ordinary differential e...quations by similarity transformation. The ODE system is solvable numerically for example using higher derivative method. The investigation is focused on the influence of governing parameters corresponding to various physical conditions. Numerical results are exhibited for the dimensionless wall skin friction and for heat transfer coefficients at the wall, along to distributions of the velocity and the temperature.
Nowadays, the automotive industry is focused on weight and size reduction. Main advantage of this weight and size reduction are improving the fuel economy. The specific fuel consumption of a vehicle can be improved through e.g. downsizing area of heat loss, if we focus on vehicle with weight reduction. Weight reduction can be done by replacing...material or by changing the size (dimensions) of components. In the present work we have focused on Audi A6 muffler, troubleshooting and optimizing the muffler by changing pipe length of inlet and outlet, also by replacing the original mesh plate to porous pipe. Based on optimization, prototype has been built with the help of 3D design tool CATIA V5 and the calculations of transmission loss (TL) have been performed by MATLAB. Plane wave-based models such as the transfer matrix method (TMM) can offer fast initial prototype solutions for muffler designers. The principles of TMM for predicting the transmission loss of a muffler was used. Result of this present study of an existing muffler has been analysed and then compared with vehicle level test observation data. Noise level have been optimized for new muffler design. Other literatures were played significant rule for validate our results.
The rack railway is a special type of railroad. There weren”t much built worldwide, and their number is decreasing. Now, in Budapest, there is a possibility to create an interoperable vehicle, based upon the experience gained from the previously operated line, and all the research regarding its unique characteristics. One from the many import...ant sector of its operation, is the rail/rack/vehicle system. Its mechanical model is far more complex than a traditional railroad vehicle. We will demonstrate its behaviorial differences from a traditional railroad vehicle.
In this paper an experimental study will be carried out, on the influence of geometry, using different compliant mechanical couplings. In the first part of the paper will be presented the compliance of the couplings and a number of consecrated works on this theme will be quoted. The article continues with the case study made on three types of c...ompliant joints. These joints and the mechanics that substitute them will be presented. Towards the end of the paper we explain the experimental method and its results. The final ideas concerning this work will be filled out by conclusions and research directions.
We carried out the measurement of the three components of the cutting force as a function of the modification of the depth of cut during the longitudinal turning process. The results show that if we increase the depth of cut, all three components of the cutting force shows increasing tendency, regardless of how much the cutting speed and feed s...peed were performed during the measurements    .
The efficiency and the life rating are essential characteristics of mechanical drives. The traction drives with proper geometry can avoid the geometrical slip and their efficiency can exceed that of the gear drives. The elements has hardened steel surfaces, the lubricant is rheopectic. There is no danger for thinning the oil film and consequent...ly for connecting the asperities. The traction drives are relatively noiseless, they are applicable for increasing speed in particular. There are some problems to be solved in friction drive. This is the necessity of clamping force. A simple machine element usually make a constant clamping force, a tensioning mechanism can be too complicated. The ideal solution is a simple design which assure a clamping force that is proportional to the instantaneous external load requirements. The authors suggest a modified machine element – a helical torsion spring, an elastic one, instead of the original, rigid annular wheel – that comprises both the driving and clamping functions, and the latter one is proportional to the external load, so that the principle of self-help operates.
The Physical Internet (PI or π) is one of the most decisive ideas for future logistics systems. The idea behind it is to implement logistic systems which apply the principles of Internet information flow. Simultaneously technological innovations of Industry 4.0 have also appeared. Our current research deals with the applicability of the tools...of Industry 4.0 technology in the PI system. Following the literature review we analyse the individual technological tools that could improve the functioning of PI components. Subsequently we will detail the usability of a specific Industry 4.0 tool and finally determine the future research steps.
The economic and environmental sustainability issues in supply chain management have integrated by many researchers in the past decades. The ergonomics as a social aspect of sustainability had received a little attention by researchers. Therefore, the aim of the paper is analyzing the flexibility of developed inventory cost model with relaxatio...n allowance and endurance time as a social aspect of sustainability. The effects of distance, unit weight of item and total number of items on relaxation allowance, the total cost of logistics operation and the EOQ model were investigated. The analyzed mathematical model was a single operator-single material model which covered transportation of fixed amount of raw materials from storage plant to production plant by manual material handling with simple cart and picking, storing, pushing and pushing back with empty cart for manual handling of the products. The different parameter values applied for analysis such as total amount of handled items (Q) changes between 500 pcs to 2750 pcs, unit weight of item (w) changes between 0.1 kg to 1 kg, distance of movement by manual material handling for picking and storing motions (d1) changes between 2 m to 3 m and the distance between the storing equipment and the supermarket of the production line for pushing motion (d2) changes between 15 m to 20 m. The results of the analysis indicated that the longer the distance of movement for all motions leads to decrease in savings of the model compared to EOQ model. The increase in unit weight of item is increase the savings obtained from application of our model and decrease the optimal lot size. There was no specific change on savings or optimal lot size as the total amount of handled item is increase. The compared results indicated that an increase in d1 and d2 lead to an increase in optimal lot size and increase in total cost of the model. Consequently, the analysis has shown that a decrease in lot size would be the better way to improve both ergonomic conditions and total cost of production in any different parameter values. Finally, the analysis of the inventory model with ergonomics were proved that this model is suitable for different industrial practices.
This paper deals with the control of an inverted pendulum. Balancing techniques are used in great many controlling problems. The inverted pendulum problem is often used as a benchmark. The theoretical background is well-known and easy to treat. A commercially available Rexroth axis controller and a CKK compact module are used to control the inp...ut of the system, which is usually applied in industrial fields. A test bench has been designed and built. A PLC based program has been developed to swing up the pendulum from the rest location to inverted position and LQR controller is designed to balance the system.
In this article, we would like to introduce the problems caused by vibrations in case of polymer turning processes. Nowadays there is a lot of research in this topic, to avoid the unnecessary phenomena of vibrations. The two most common methods are the Spindle Speed Variation (SSV), and the Vibration Assisted Machining (VAM). In case of SSV, th...e CNC machine can increase and decrease the speed of spindle continuously during turning which can significantly reduce the effects of chatter. This method is beneficial for longer workpieces when there is not any support except the chuck. Vibration-assisted machining can be used to minimise the problems caused by vibrations. VAM combines precision machining with small-amplitude tool vibration to improve the fabrication process. It has been applied to some processes ranging from turning, drilling to grinding. Based on the enumerated above we made some trial measurements about the basic vibrations of the turning tool shank. The tests were done on an NCT EUROturn-12B CNC machine which can found in the workshop of our institute. The tested material was Polyamide 6 because this is the most commonly used polymer in the industry. In the future, we would like to test some other basic and composite polymer materials too. The equipment was served by a specialist from SPM Budapest Kft. With these tests, our goal was to make sure that the equipment and the measuring setup are suitable for our future research.
The aim of this paper is to introduce the design of testing method for the prediction of the life and acceleration methods of the micro switches applied in different type of garden tools. These products will be tested for complex stressing, for example higher temperature, humidity, current load and so on. Therefore, the most important informati...on and multi-factor acceleration models are summarized, the Weibull, the lognormal and the exponential distributions which are suitable for performing and evaluating tests.
The vibration properties of agricultural tractor’s tyres significantly influence its response in terms of the exposure of the human operator to mechanical vibrations, which is still one of the key problems in the design and exploitation of tractors. The behaviour of the tyre in this sense is significantly influenced by the mechanism ofgeometr...ic filtering of the short-wavelength unevenness of the unprepared ground mostly encountered by tractor during in-field operations. Herein, this aspect of tyre behaviour was studied with tyre rolling quasistatically over singular obstacle. Based on experimental results, neural network based model of tyre enveloping behaviour was developed. Main model properties are high computational efficiency, simplicity regarding number of input quantities and absence of the need for explicit parametrization etc. Main shortcomings of modelling approach used are high developing effort, labour-intensive experimental preparations and lack of flexibility regarding tyre design and operating parameters
Main source of vibration excitation for off-road vehicles are ground profile undulations. Most unprepared terrains are characterized by wavelength of unevenness that is of the order of magnitude of the contact length between tire and ground, so that, due to its shape and elasticity, tire actually behaves as geometric low-pass filter transformin...g real road profile geometry into effective vehicle vibration excitation. Since this effective profile represents real vehicle excitation, it is of interest to study this filtering behaviour in more depth. In this work, investigation of this kind of tire response has been studied for agricultural tractor tire rolling quasistatically over singular road obstacle. Frequency analysis of road excitation and tyre response was carried out in order to obtain their spectra and frequency response function magnitude of the tyre as filter was obtained by dividing input by output spectra. Final assessment of frequency response function magnitude was obtained by averaging instances obtained for different dimensions of input obstacles.
WEDM technology is among the final technology. It is characterized by the high quality of the machined surface. Therefore, a small geometric deviation from the desired shape, position, orientation or run out may have a significant impact on the functionality of the finished component. Its range is largely influenced by the accuracy of the appli...ed electroerosion device, the precision of the workpiece and tool setting, the machining method, but also the combination of each other and the adjustment of all process parameters. They result in the final quality of the machined surface not only in terms of roughness parameters but also in terms of geometric precision of the machined surface. The aim of the paper was to describe the possibilities of improving the geometrical accuracy of WEDM with thin brass electrodes. At the same time, it contributes to an existing database of knowledge that defines the influence of selected aspects on the geometrical accuracy of the machined area in the production of circular openings.
Additive Manufacturing has been invented in 1981 at the University of Texas, and to this day it has grown to be the most versatile and promising manufacturing technology in the market, both the industry and health care system has noticed this. Additive Bio-Manufacturing (ABM) techniques, which can be used in health care, are highly in demand, a...nd researches have been going on to make these technologies safer and even more versatile. For more utilization and versatility, special attention is required to develop new materials which can help in increasing the service life, bioactivity, cell growth along with the desired mechanical properties, and to find the right manufacturing parameters for creating optimal products. The aim of this review is to present the available main Additive Manufacturing technologies, and particularly the biomedical usability of Additive Manufacturing.
In this paper a vehicle dynamics model is presented, which is an example that contains all the necessary aspects of making a decent vehicle model. Several examples show the use of such a model: basic vehicle dynamics phenomena can be recognized with the simulation of a detailed vehicle model. We are dealing with the connection between downforce... and under/oversteer in this paper. In addition, the use of numerical simulations in the field of control systems is pointed out by an example of simulating an ABS control for the vehicle.
Auxiliary equipment used in the automotive industry, such as generator, air conditioner, or starter, is often exposed to harsh conditions, for example splash water, frost, or serious dust load. Therefore, these auxiliary devices are intended to be prepared by the manufacturers to these conditions. The topic of this paper is a part of the analys...is of the dust control of generators, which in principle is no different from the examination of other equipment. The flow around the generator and in the dust chamber was simulated by Ansys FLUENT.
Tomato is a highly perishable food, thus preservation is required to meet the continuous market demand compared to the unbalanced yearly production peak. The aim of this paper is to show a detailed insight into infraradiation based drying process. Furthermore, to widen the possible usage range of a well-known approximation method for describing... the temporal moisture variation in function of process parameters. The mass decrease of tomato slices was examined, in function of specific radiation power, heat source and sample distance, in forced and natural airflow. Based on the results dimensionless moisture ratio change over time was fitted as an exponential function, which may be used in industrial drying process optimization.
The crankshaft of today’s internal combustion engines with high performance output are exposed to harmful torsional oscillations originated from the unbalanced gas and inertial forces. To avoid the fatigue damage of engine components, caused by the undesired vibrations, torsional vibration dampers can be applied. Viscodampers are one type of...the torsional vibration dampers, which operational fluid is silicone oil. For cost-effective R&D activities and production, finite element and finite volume numerical discretization methods based calculation techniques must be involved into the engineering work supported by the modern computer technology. The aim of this paper is to provide an insight into the multidisciplinary design and development process of visco-dampers in vehicle industry applications. Four different examples as structural, fatigue, CFD analyses and structural optimization have been introduced in the present work. It turned out from the static structural and fatigue analyses, that the investigated damper has safety factor over the limit for both static structural and fatigue analyses, so it is suitable for the given load conditions. In the structural optimization process 34.36% mass reduction has been achieved. According to the coupled fluid dynamic and heat transfer simulations a rather stagnating air zone evolved between the engine and the damper during the operation, which can cause efficiency reduction of cooling fins mounted onto the housing. In light of the numerical results, the suitable damper position has been determined for the highest heat transfer.
It has been an accepted tendency in the industrial practice since the last third of the 20th Century to decrease the living labour demand of the manufacturing processes. One of the main tools of it is the automation of production. In the design, the construction and the programming of the developed automata, the results of electronics, informat...ics and mechatronics can be used. All of the scientific fields mentioned above undergo intensive development. By the application of the results achieved in the design of the applications, the monotonous, dangerous and tiresome work not requiring expertise can be assigned to machines. In the longer run, the application of the automata is beneficial also in financial aspect, since the costs of living labour are continuously growing, while that of the mechatronic and technological devices show a rather decreasing tendency. Reliability is also an important aspect. It is well known for everyone that a well-designed and programmed automatic device performs its task without mistakes. If there is any objection or breakdown, on the basis of the currently valid safety technology rules, the machine stops, does not trigger any damage and after its repair, work can be continued.
In this article the clinched joints were analyzed by finite element method (FEA). The base materials were advanced high strength steels (DP 600, DP 800 and DP 1000). The model validation procedure was done by the DP 600 type of steel sheets; the other two types of steel were only simulated. The goal was to determine the geometrical properties o...f the joints with different strength steels. The FEA model was the same in every mechanical point of view therefore the results are comparable. The main geometrical parameters of the clinch joints are the neck thickness (tN), the undercut (C), the bottom thickness (tB) and the height of the protrusion (h); these values were compared.
In our days, the fight against pollution has become a real challenge for the state. recycling is one of the solutions that is adopted in several nations to reduce the rate of plastic discarded in nature. The amount of plastic waste has been increasing for decades contributing to the environmental pollution that is one of the most serious proble...m of the mankind. according to the statistics not only the household plastic waste, but the industry discharge is increasing because the utilization of plastic as a raw material is more and more extending. plastic can be found in a lot of products, huge number of bottles, plastic bags, computers, auto parts are sold every day. The current applications for using recycled plastics in fabrication and design are fairly limited, on a small scale, plastics (such as abs, HDPe1, or Pe2t) are shredded and formed into pellets, and then either extruded into lament to be used in existing 3d printers, or injection molded into small parts and pieces of larger components. at a large scale, recycled HDpE is melted into sheets and either used directly as sheets in construction, or then heat formed from a sheet into components for construction. these methods of fabrication using recycled plastics are the norm because of their straightforward processes. nevertheless, each method leaves some complexity to be desired. This paper we study the types of plastics and diagnose the pollution caused by the latter. this allowed us to design and size a recycling station of plastic into filaments for three-dimensional printers. this station which will contribute to the fight against pollution. the station consists of two machines for grinding of the plastic and the other for the extrusion of the desired filaments. we were able to make a theoretical academic study on both machines and also we designed with solidworks 2015. The theoretical study is spread of the mechanical calculations necessary to the design and validation of the structure using the tools. as the prospect of this project, we want to complete the achievement of this station while completing the crusher and extruder mechanically. then switch to electric and electronic parts (introduction of engines, sensors and wiring...). In the case of waste plastics that are recyclable and reusable. the most widely used are polyethylene terephthalate (pet, used for synthetic fibers and water bottles), and second high-density polyethylene (hdpe, used for jugs, bottle caps, water pipes).
In the human knee joint, a degenerative wear of the joint can be formed, the common treatment of this disease is the total knee prosthesis geometry replacement and prosthesis implanting, the aim of our research is the study of the human knee joint with applications in prosthesis, we will develop a method by creating a virtual knee prosthesis ge...ometries, we will generate the geometries using the ADAMS program and examined on a special knee prosthesis qualification equipment.
Operational parameters can be easily controlled at lab scale experiments for an anaerobic digestion process. Our aim is to design a lab-scale digester equipped with an impeller to investigate how the geometry of impeller and different mixing modes effect the biogas yield of digester. Further, the methods of measuring the gas volume, gas composi...tion, mixing intensity, torque, temperature are discussed in this article. The assembling of 4 liters digester is described which can be operated at various operating parameters which control the anaerobic digestion process. Mixing is very important to enhance efficiency of an anaerobic digester. To attain mixing Maxblend impeller is used in this lab-scale digester due to its better performance for mixing and power consumption. Various design consideration has been described.
Areas after mining or calamity are not amenable to immediate afforestation and require some adjustment. After removal of wood biomass, the rest of the residue is scattered throughout the area. To modify them, Several methods can be used to remove it. The optimal conditions for the planting environment and the subsequent adaptation process of th...e planting can be achieved by its mechanical, biological, chemical treatment. The basic prerequisite for a successful renewal of forests is their release from undesirable increases, in some cases from foams (trees) from mining waste. The area is also released when forest nurseries, seed plantations, etc. are established. The main purpose of the release of surfaces is to achieve the maximum throughput of the area for the machines to be moved. They wear during work. Wearing is a permanently undesirable change in the surface due to the interaction of functional surfaces or functional surface and wear medium. A tool that does not have any editing can go into a state where it can no longer be used anymore. An experiment was carried out in which 9 new teeth were placed on the rotor of the crusher and their wear patterns were observed. The article shows the progress of tool wear over time.
Diagnostics of batteries using advanced methods have gained remarkable roles in the past few years. This study focuses on the type of measurements, tests and methods to reveal and classify them. During manufacturing and operation several faults could emerge in batteries including non-optimal operation conditions, operators without experience, a...nd finally, random changes in batteries under physical and nonphysical conditions. Improper handling of batteries and battery cells man cause operation failures or, in the worst case, accidents. To reveal these problems several methods are applied in industry and in scientific laboratories. For a comprehensive analysis of battery management, artificial intelligence and Industry 4.0 methods can be used very effectively. Big Data analysis in its standard form is not a new achievement, but other mathematical tools could be applied to control monitoring such as Fuzzy Logic or Support Vector Machine (SVM). They are efficient tools to analyse the deviation of batteries condition because it can detect sudden changes, parameter deviations and anomalies, and the user’s behaviour and habits. This article gives a description about the most important battery testing methods and the connection between Big Data and Operation Management with Artificial Intelligent (AI) methods.
I display this paper the chipping front metal of cutting allocated geometric, considering particular the friction. I catch the attention energy's balance sheet someday metal of cutting, open one new direction the manufacture technology. I display this new direction's metal of cutting condition. but built I delineate his paper final division thi...s new policy searching programme, consumed trial instruments as well as the evaluation's mode.
The digitization of ancient sculptures is particularly relevant and necessary in relation to the preservation of the cultural heritage. And the studied ancient models have their unique identity in terms of their visual and functional qualities. In parallel, the study aims to optimize the technological process related to photogrammetric measurem...ents and calculations, technological tools and specialized software applications such as Autodesk ReCap, Blender and MeshMixer. The used models in the article are for re-presentation of popular ancient models & artifacts from city of Varna (by the ancient name Odessos). By using a 3D print device, one of the resulting digitized models of an ancient angel will materialize by applying specific techniques to redesign its geometry. The completed 3D printed item of re-designed model of ancient stone angel is only for personal and non-comercial use. One of the main point in the article is to show advanced computer techniques for teaching and studying. The information in this article has been built for helping other specialist working in digital field regarding photogrammetry. Also the material can be useful for designers, engineers, archaeologists and others in their work for the publicity of ancient treasures.
The aim of this study is to present a thermal analysis of a permanent magnet synchronous machine based on finite element method. The developed model can be used to predict temperature distribution inside the studied motor during the rated operation. Electromagnetic computation is carried out with the aid of two 2D finite-element (FE) simulation...s on the cross-section of the PM motor. To analyse the process of heat transfer in an electrical machine, empirical correlations are used to describe the convective heat transfer from the different surfaces of the PM motor. The heat transfer coefficient is determined using dimensionless numbers and Nusselt number. After the loss calculation, the temperatures of the machine are calculated by using 3D finite element method. The results obtained by the model are compared with experimental results from testing the prototype electric motor.
The paper presents the experimental results of a research aimed at the distribution of the temperature on the circular saw blade body. The temperature was measured at two distances from the centre of the circular saw blade body (70 mm, 140 mm) by means of an infrared thermometer. Two circular saw blades with the diameter of 350 mm and a variabl...e adjustment of the body (with slots and without the coating, with both slots and coating) were used for the longitudinal sawing of the spruce wood (Picea excelsa) with the thickness of h = 37 mm. Feed speeds ware vf1 = 14 mpm, vf2 = 17 mpm and vf3 = 20 mpm. Cutting revolutions n = 4100 /min. were constant. The measured temperature was in the range from 21 °C till 27 °C. The highest measured temperatures were recorded on the circular saw blade with the slots and coating.
The paper describes a method of speed (velocity) computation, named mixt profile, during a motion upon an imposed linear trajectory. The method assures an accurate positioning at the end of motion (movement), in a well determinate time lapse. The described method is linked with position vector computation, about a robotic arm.
The aircrafts are responsible for emitting several types of pollutants, especially the pollutants in the form of NOX, CO2, CO, UHC, SOX and Particulate Matter PM (smoke/soot). The impact of aviation emissions on the global is well known, where these emissions modify the chemical and microphysical properties of the atmosphere resulting in change...s of earth’s climate system, which can ultimate in critical changes in our planet fragile ecosystem, also the pollutants produced by aircraft engines cause many health problems. This is why the International Civil Aviation Organisation (ICAO) is seriously seeking to control the emission levels by issuing new standards during the successive meetings of the Committee on Aviation Environmental Protection CAEP (CAEP/01 in 1986, CAEP/2, CAEP/4, CAEP/6, CAEP/8, etc). The new regulations include more stringent standards aimed to reduce emission levels, this led to increased interest in low emission technologies. In this paper, a comprehensive review of low emissions combustion technologies for modern aero gas turbines is represented. The current low emission technologies include the high Technologies Readiness Level (TRL) including RQL, TAPS, DAC and LDI. Also, there are advanced technologies at lower TRL including LPP, ASC and VGC.
This paper introduces our ongoing research in the field of smart livestock farming. The base idea in this research is to take some industry based concepts, and adapt them into agriculture. In Industry we live the fourth industrial revolution, which is not a technical, but an organization revolution. So in this concept there are two key id...eas, which are digital twin, and digital shadow. This article is about creating digital twin and digital shadow of a modern pig fattener. These models are based on the literature, and are identified on the data shared in these. However, these models can’t be used on real systems before identifying them on the actual circumstances. At this stage of research only digital twin of the product was created, and only some aspects of it. This however can simulate an average porkers feed consumption, weight growth and calculate the weight on certain stages of breeding. Further development is ongoing and our target is to make a fully functional model of a pig fattener.
High pressure die casting (HPDC) is a manufacturing process for producing accurately dimensioned, sharply defined, smooth or textured surface metal parts. It is accomplished by injecting liquid metal at fast velocity and under high pressure into reusable steel dies. Compared to other casting processes, die casting is at the top end of both velo...city and pressure. The high velocity translates into a very turbulent flow condition. The process is often described as the shortest distance between raw material and the finished product.
The vehicle applies a normal load to the terrain, which causes sinkage and motion resistance. To forecast the normal pressure distribution on the interface of a vehicle–terrain and the tractive performance of a vehicle, the response of the terrain to normal load (which is characterized by pressure–sinkage relationship equations) must be mea...sured. This paper presents the common conventional pressure sinkage models used in terramechanic and the modification that happened to this models. In addition the features of the new models.
In our previous publications [1, 2], we described our vehicle dynamics simulation program which was developed in MATLAB environment. We also discussed its use for optimizing the technical parameters of electric driven vehicles. We detailed the model and simulation of the series wound DC motor which is part of the program. Besides, we described...the experimental procedure by which we can determine the electromagnetic characteristics of the motor from the input parameters of the simulation program. In the present publication we deal with the determination of the dynamic characteristics of the motor (the moment of inertia of the rotor, bearing and brush resistance torques) experimentally. Knowing the above mentioned electromagnetic and dynamic characteristics, we can carry out the simulation of the motor and the results of the simulation can be compared to the results of the test measurements.
The Global concern is moving toward making a revolution in favor of exploitation of renewable energy in order to improve environment conditions, limit emissions and minimizes consumption of non-renewable resources within the planet. In this context, it is necessary to focus on the transport sector as it contributes of at least 30% of the total...primary energy consumption. Therefore, a set of rules must be developed to maintain economic, environmental and social sustainability to address the problems so as not to increase their severity and these cannot be done unless there are joint measures and regulations from governments, companies, manufacturers and users. Unfortunately, the Jordanian transport system mostly depend on the individual transport which supported by cars, and that because of the weak role played by the public transport sector, especially at the capital, Amman. Buying hybrid cars (internal combustion engine + electric motor) and Electrical Vehicles (EV), in the past few years in Jordan is increasing, which is compatible with the global trend to use Electrical Vehicles (EV) instead of Internal Combustion Engine vehicles (ICE) powered by fossil fuels, this issue will have a direct and indirect impact on gas stations companies, also it will have direct impact on labor sector and the current car industry since electric charging stations as well as EV manufacturing is not labor intensive. The main purpose of the study is to show how much it is necessary now to start theoretical assumptions through studying the expected annual increase in passenger cars and its impact on sustainability and predicting the future fuel consumption and emissions and compare them with the base situation.
This paper deals with the kinematics and control of a planar cable robot , which is driven by four DC motors with gear. Cable robots are frequently used e.g., for the motion of cameras in sport halls and stadiums and also in high storage logistical systems . Main goal of this research work is to design and build a test bench with low budg...et, which can model the motion of real life cable robots.