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Crank train of a two-stroke automotive engine
Štrba, Matej ; Janoušek, Michal (referee) ; Drápal, Lubomír (advisor)
The subject of this diploma thesis is the analysis and comparison of three-cylinder two-stroke engines with a displacement of 1000 cm3 of the Wartburg 353. The introduction of the thesis is a research that discusses the history of car production and development in Eisenach during the second half of the 20th century. The main subject of research is the engine, to which the vast majority of work is devoted. Using the available simulation tools, the cylinder pressure indication is determined, the crankshaft of the two engine variants is subjected to balance analysis, dynamic analysis in terms of torsional vibrations and bearing load is performed using the MBS method, then the two variants are compared.
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Spark-ignition engine design for hybrid passenger car
Smejkal, Jan ; Dlugoš, Jozef (referee) ; Drápal, Lubomír (advisor)
This diploma thesis deals with design of four-cylinder spark ignition naturally aspirated engine with indirect fuel injection for hybrid passenger cars. The thesis begins with research of engines that meet the requirements of the thesis assignment. The research is followed by design of the engine, where the main components are described in detail. The last part deals with FEA analysis of the connecting rod which is followed by analytical computation of high cycle fatigue by the LSA method.
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Model engine for F4 class aircraft
Čížek, Petr ; Janoušek, Michal (referee) ; Drápal, Lubomír (advisor)
The diploma thesis deals with the construction of two-stroke engine for the propulsion of a scaled aircraft model, which can fall into the category FAI F4. The introduction of this thesis carries out research and familiarization with the category of F4 aircraft. Part of the research is a brief overview of two-stroke and four-stroke variants of model engines, with the fact that more attention is given to the construction details of two-stroke engines. Subsequently, the design and thermodynamic 1-D simulation of the power parameters of the designed engine are carried out, followed by dynamic simulation to verify the lifespan of the engine bearings.
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The influence of a computational model of crank train dynamics on engine block load
Charvát, Adam ; Dlugoš, Jozef (referee) ; Drápal, Lubomír (advisor)
This work investigates the influence of the computational model of the cranktrain dynamics on the engine block load around the main bearings depending on the discretization level of the bodies used. Four variants of the computational model of the cranktrain in the Multi-Body System software SIMDRIVE 3D are compared with respect to the load on the main bearings. Based on the obtained loads, a strength analysis of the EA211 series 1,5 MPI mass-production engine block, manufactured by ŠKODA AUTO, is performed, including the influence of pre-stress during the assembly of the cylinder head and bearing caps. To evaluate the results, a fatigue life calculation is performed, and the endurance safety factors in the grooves on the bottom of the engine block are compared.
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Variable turbocharger turbine geometry
Řezáč, Vojtěch ; Dlugoš, Jozef (referee) ; Drápal, Lubomír (advisor)
This thesis is dedicated to design of turbocharger’s boost pressure regulation using variable turbine geometry. In this thesis are mapped commonly used methods of turbine flow regulation. With respect to all information collected there were created new designs which were compared between each other and with currently used Garrett VNT system focusing on performance, flow area and operating forces which were obtained using advanced numerical methods in ADAMS View software. At the end of this thesis are presented benefits and drawbacks of each design. In the very end are presented next steps in further development.
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Spark-ignition engine concept for hybrid passenger car
Břoušek, Roman ; Böhm, Michael (referee) ; Drápal, Lubomír (advisor)
Thesis aims on calculating method of engine conception for hybrid power train usage. Aim is to describe briefly overview of common combustion engines in hybrid power trains of the passenger cars. According this overview a proposal of naturally aspirated spark ignition combustion engine by specified parameters in 1-D CFD will be made, while the effort is to take into account less complexity and production costs at the same time higher efficiency in the most load modes.
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Increasing the Volumetric efficiency of a two-stroke engine
Šmahel, Matěj ; Drápal, Lubomír (referee) ; Beran, Martin (advisor)
This bachelor thesis deals with a design modification of a chosen two-stroke engine with respect to an increase in its filling efficiency resulting in increased performance. The first part of the thesis describes basic principles of a two-stroke engine alongside a detailed description of all its cycles and their influence on the filling efficiency. The second part is dedicated to the design modification itself ending with a result evaluation.
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Crank mechanism with a high mechanical efficiency
Drápal, Lubomír ; Tůma, Jiří (referee) ; Páv,, Karel (referee) ; Píštěk, Václav (advisor)
This document describes the possibilities of increasing the mechanical efficiency of the crank train of an internal-combustion engine. For this purpose, a concept with a reduced number of main bearings is chosen and its contribution is verified experimentally. The proposed solution consists of an innovative crankshaft design of a four-cylinder spark-ignition engine with only three main journal bearings and laser-welded sheet metal crank webs. The new design is compared to the mass-produced one in terms of friction losses, vibrations and loading of engine parts by means of simulations of crank train dynamics using the Multi-Body System. The increase in vibration, accompanied by a reduction in friction losses, is compensated by a torsional vibration damper and its effect is experimentally verified. Experimental research of laser welds on the crankshaft in terms of fatigue life is also described. The overall potential is also summarised and further possible development of this innovative and patented design is outlined.
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Piston of a spark-ignition engine produced by additive manufacturing
Valtrová, Martina ; Dlugoš, Jozef (referee) ; Drápal, Lubomír (advisor)
The first objective of this thesis was compiling research about currently produced pistons for internal combustion engines and about additive manufacturing and based on the acquired information deciding which type of piston makes the most of the advantages. Following this research, the next step was creating a design adjustment of a piston, which was previously designed with the conventional methods of manufacturing in mind, in a way that would make the best use of the different possibilities of additive manufacturing. There was also an optimisation carried out, which depicted the densities of material elements in the piston, showing where the material was less important. There were three variants of the additive manufactured piston created, ranging from a relatively conservative design, which could be theoretically produced by conventional methods with a more substantial subtraction of material added, to a design which could only be produced via additive manufacturing. A thermo-structural analysis at maximum engine load was carried out for all these piston models. Based on these data, a conclusion was made, whether the use of additive manufacturing was justified over the use of the conventional subtractive methods.
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