1/2012
Tisza M., Török I., Kocsisné Baán M.
Innovative materials processing technologies 3
The authors reported their research made in the framework of the TÁMOP project at the University of Miskolc in the research team entitled Innovative materials processing. Research in this group is performed in the following topics: Welding, Heattreatment and Surface Engineering, as well as Metal Forming. In this paper, the main objectives of these research activities, as well as the results achieved during the fi rst period of the project are shortly introduced.
Meilinger Á., Török I.
The application of friction stir welding of aluminium alloys 7
The friction stir welding is a new and unusual welding process, which is spreading more and more in different fi elds of industry. It is economically usable for welding of aluminium and its alloys, copper and its alloys, although current researches are very promising for steel as well. The research points out that high quality welds can be made by the correct selection of technological parameters.
Kovács A., Varga Gy.
Experimental results of minimum quantity lubrication drilling of wear resistant steel 11
This article aims to give an overview about how during the cutting procedure a) the feed direction force that is the thrust, b) the cutting torque, c) the tool wear, d) the change of surface roughness, if the cutting is done under near dry conditions using different cutting speeds and feed rate parameters.
Kundrák J., Pálmai Z., Gyáni K.
The technological conditions of white etching area in hard turning 15
In this paper the authors deal with the technological conditions of the development of this white etching area on the surface of the bore hole of cogwheels made of 20MnCr5 steel. They conducted experiments with various technological parameters. As a result of these experiments, we elaborated an empirical formula by which we can decide if a white etching area can be expected to develop in a particular case.
Maros Zs.
Investigation of abrasive waterjet cutting of an aluminium alloy 19
Effi ciency and quality of the waterjet cutting process can be characterised by different output parameters, like surface roughness of the machined surface, geometry of cutting kerf (depth, width, tapering). Some results of experiments carried out for investigation of effi ciency and quality of cutting of aluminium alloy surfaces are summarised in the paper.
Pálmai Z.
The relationship of machine rigidity and tool endurance in cutting 23
Vibrations play an important role among the reasons for the well-known scatter of tool life in cutting. In vibration, the results of the equation solved by taking fl uctuating cutting speed and feed into consideration clearly show that wear rate in vibration hardly depends on frequency but intensity has a major impact. The unfavourable effect may be mitigated by increasing the rigidity of the machine.
Bencs P., Szabó Sz.
Improvement of measurement techniques for analysis of unsteady air temperature field 27
Temperature fi eld measurements around solid bodies (where the temperature of the body is different from the ambient temperature) are particularly diffi cult when the body is placed in air fl ow and the velocity and temperature fi elds are unsteady. The objective of this article is to report on progress made in this research, particularly on our newest results for the two techniques used, standard Schlieren method and Background Oriented Schlieren (BOS) technique.
Bolló B.
Flow around a heated circular cylinder 31
Numerical investigation were carried out to study the effect of cylinder heating on the characteristics of the fl ow and heat transfer in a two-dimensional laminar fl ow of air past a heated circular cylinder for Reynolds numbers of 150. The effect of dynamic viscosity, density, thermal conductivity and specific heat variations on the fl uid dynamics occurring with the cylinder heating was analyzed separately.
Hajdú S., Lakatos K.
Cross-flow turbines with pitch controlled blades 35
A characteristic feature of cross-fl ow turbines is a strong fluctuation in the circumferential force that generates axle power, because the interaction between the blades and the medium is not constant. This paper is about how to improve the effi ciency of the turbine using actice pitch control.
Kalmár L., Janiga G., Fodor B., Varga Z., Soltész L.
Numerical investigation of the flow in one-stage blower 39
This paper deals with the CFD investigation of the fl ow in a one-stage radial fl ow blower-aggregate. The main aim of this numerical study is to compute the relevant operating characteristics of the blower and to determine detailed information about the fl ow characteristics inside it.
Kalmár L., Hellmann R., Régert T., Varga Z.
Numerical investigation of unsteady heat transport procedure in high power LED module 43
High power UV LED modules still generate a signifi cant amount of heat that has to be effi ciently dissipated in order not to decrease the LED output power and lifetime. The scientific task includes the simulation of the temperature development on the high power UV LED module taking into account the environment of the module and also the active air cooling.
Tollár S., Lakatos K.
Vibration acceptance test of a diesel engine 47
The authors started an experimental test on a model diesel engine. Out of the conventional torque-speed curves we recorded the effective vibration velocity (vRMS) curves also. They used the throttle position as parameter for the determination of the engine characteristics.
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