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Mechanical losses of modern powertrains
Vaňkátová, Kateřina ; Czakó, Alexander (referee) ; Štětina, Josef (advisor)
This bachelor thesis deals with the issue of mechanical losses in internal combustion engines of passenger cars. The following chapters describe the origin of mechanical losses, the area of their occurrence in the engine and in the accessories driven by the engine. Furthermore, the work summarizes the current knowledge in the field of reducing mechanical losses and methods of determining the engine losses during their development. The aim of this work is to acquaint the reader not only with the issue of mechanical losses, but also with their significant negative impact.
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Computational Modelling of Piston Ring Dynamics
Dlugoš, Jozef ; Raffai, Peter (referee) ; Novotný, Pavel (advisor)
Piston rings are installed in the piston and cylinder wall, which does not have a perfect round shape due to machining tolerances or external loads e.g. head bolts tightening. If the ring cannot follow these deformations, a localized lack of contact will occur and consequently an increase in the engine blow-by and lubricant oil consumption. Current 2D computational methods can not implement such effects – more complex model is necessary. The presented master’s thesis is focused on the developement of a flexible 3D piston ring model able to capture local deformations. It is based on the Timoshenko beam theory in cooperation with MBS software Adams. Model is then compared with FEM using software ANSYS. The validated piston ring model is assembled into the piston/cylinder liner and very basic simulations are run. Finally, future improvements are suggested.
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Analysis of possibilities to improvement induction motors efficiency
Novotný, Jiří ; Hájek, Vítězslav (referee) ; Mach, Martin (advisor)
In the first part of the master’s thesis dealing with the increasing efficiency of induction motors there are briefly presented basic information about induction motors, followed by an overview of the losses of induction motors. The next part deals with the ways to increase efficiency of induction motors without increasing tooling costs. The practical part consists of four measurements of four induction motors, with their various mechanical adjustments to make comparing benefits of these modifications possible. The measured results are compared by a finite element method in Maxwell 2D Design program, in which the same motors are simulated as measured. Theoretical knowledge about the increase of efficiency is practically applied while being implemented in the simulations.
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Automatic measurement of induction machine using LabVIEW
Halfar, Lukáš ; Huzlík, Rostislav (referee) ; Bulín, Tomáš (advisor)
The main purpose of the thesis Automatic measurement of induction machine using LabVIEW was to develope an automated measuring system, which is used to perform tests of induction motors. The algorithm of the system is programmed in LabVIEW. In the practical part of this thesis, a measurement of the motor Atas Elektromotory Náchod a.s. T22VT512 is carried out, in order to verificate functions of the algorithm, and to perform tests of the motor to analyse losses. Another part of the work is dedicated to the electromagnetic calculation of the motor T22VT512. For this purpose, two softwares with different principles of calculation have been used. Firstly, the calculation is solved by an analytical based software called RMxprt. Secondly, the software Maxwell 2D is used to make the calculation of electric and magnetic fields by the finite element method.
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Losses analysis of small induction motors
Šišák, David ; Cipín, Radoslav (referee) ; Mach, Martin (advisor)
This bachelor thesis deals with analysis of losses of small induction motors. The first part of the project introduces the principle of operation and construction of induction motors. Furthermore, there is dealt with issuing each losses, their origin and disposition in induction motor. The project continues performing the analytical computation of the losses of induction motor with an output of 600 W. The losses of the motor are also calculated in the program Maxvell RMxprt. In the practical part, there are the results of the laboratory measurement on that motor and measurements concerning two another small induction motors different in nominal power. In the last part, there are compared the results of individual motor losses, obtained by computations and measuring. There are also compared the measuring results of losses of chosen motors depending on the nominal output.
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Mechanical losses of modern powertrains
Vaňkátová, Kateřina ; Czakó, Alexander (referee) ; Štětina, Josef (advisor)
This bachelor thesis deals with the issue of mechanical losses in internal combustion engines of passenger cars. The following chapters describe the origin of mechanical losses, the area of their occurrence in the engine and in the accessories driven by the engine. Furthermore, the work summarizes the current knowledge in the field of reducing mechanical losses and methods of determining the engine losses during their development. The aim of this work is to acquaint the reader not only with the issue of mechanical losses, but also with their significant negative impact.
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Experimental Determination of Turbocharger Mechanical Losses
Kudláček, Petr ; Doman, Jozef (referee) ; Novotný, Pavel (advisor)
This master’s thesis deals with mechanical losses in turbochargers. The theoretical part provides general information of the methods of support the turbocharger rotor, then focuses on hydrodynamic bearings. The thesis analyzes the occurrence of mechanical losses and the effects that affect them. An important part of this thesis focuses on the determination of mechanical losses and their possibilities. A test stand was compiled for the possibility of experimental measurement of mechanical losses. Several test measurements were performed on this test stand at different operating modes. Simultaneously, the determination of mechanical losses was performed using two other methods. Based on these measurements, it was also possible to perform an evaluation and analyze the occurrence of mechanical losses depending on the set operating conditions. A comparison of individual methods for determining mechanical losses performed in the experimental part was performed. At the end of the thesis, the possibilities of the test stand were defined based on the performed measurements.
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Analysis of steel grade influence on small induction machine efficiency
Plíšek, Oldřich ; Klíma, Jiří (referee) ; Mach, Martin (advisor)
The theoretical part of the bechelors thesis examining the impact of the material of the magnetic circuit on the efficiency of induction motors is devoted to analysis of the induction motor and its losses. It also describes the measuring, including calculations of individual losses. Another theoretical part examines the impact of specific losses on the magnetization characteristics of assessed laminations. The practical part includes laboratory measurements of single phase and three phase motors ATAS Electromotory Náchod brand with multiple types of laminations. Measured values are used to calculate individual losses, which are later mutually compared. Models of measured motors with multiple types of laminations are simulated with the aid of ANSYS Maxwell RMxprt program. Analysis of engines with specific types of laminations are performed with the aid of analytical calculations. Results of calculations are compared with simulated and measured values.
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Losses analysis of small induction motors
Šišák, David ; Cipín, Radoslav (referee) ; Mach, Martin (advisor)
This bachelor thesis deals with analysis of losses of small induction motors. The first part of the project introduces the principle of operation and construction of induction motors. Furthermore, there is dealt with issuing each losses, their origin and disposition in induction motor. The project continues performing the analytical computation of the losses of induction motor with an output of 600 W. The losses of the motor are also calculated in the program Maxvell RMxprt. In the practical part, there are the results of the laboratory measurement on that motor and measurements concerning two another small induction motors different in nominal power. In the last part, there are compared the results of individual motor losses, obtained by computations and measuring. There are also compared the measuring results of losses of chosen motors depending on the nominal output.
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Energy parameters of single-phase induction machines
Janáček, Martin ; Mach, Martin (referee) ; Hájek, Vítězslav (advisor)
The master's thesis deals and introduces a single-phase inductions machines, the principle of operation, types of design and operating conditions. This thesis includes analysis of individual losses in the machine and reduce the possibility of different ways. After a theoretical proposal for reducing losses are measured by mass-produced single-phase induction machine. Further machine modifications proposed for reducing losses in the stator windings and designed a prototype machine with the adjustment of the magnetic circuit to reduce iron losses made by ATAS elektromotory Nachod a.s. The results are supplemented by a simulation using software Maxwell RMxprt and finite element method (FEM). Finally, they are compared to each machines modifications mainly in terms of energy consumption.
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