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Comparison of Hybrid Powertrain Topologies in Daily Commuting Regime
Ušiak, Michal ; Štětina, Josef (oponent) ; Vondrák, Adam (vedoucí práce)
The master’s thesis deals with modelling of various architectures of hybrid powertrains for three vehicle sizes in GT-SUITE and compares them in daily commuting operating mode. On top of making of the hybrid vehicle simulation models, control algorithms had to be created to manage the energy split between the internal combustion engine and the electric motor for each of the architectures. Routes to work and back were logged using the GPS and postprocessed to obtain the speed and the road grade profiles. Resulting data was used as an input in simulations of daily commuting. To compare all hybrid powertrain architectures, fuel economy and electricity consumption were evaluated for WLTP and daily commuting operating modes. Finally, the environmental impact of each topology was assessed based on an estimation of corresponding well-to-wheel emissions.
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Fitting and Extrapolation of Turbocharger Turbine Maps
Vondrák, Adam ; Babák, Martin (oponent) ; Novotný, Pavel (oponent) ; Štětina, Josef (vedoucí práce)
Modelling of turbine performance is a prerequisite for detailed simulation of gas exchange in turbocharged combustion engines. At the same time, the possibility to determine efficiency and mass flow capacity at arbitrary operating points is key to comparing different turbine stages. The objective of this work is to propose a single method for both purposes, so it is possible to do the comparison using exactly the same turbine performance model as in subsequent engine working cycle simulation. The source of input data is typically a gas stand measurement, which enables capturing of limited turbine operating range only. In this work, methods are proposed to improve the fidelity and robustness of turbine performance extrapolation, while optimization is employed to find the best fit in terms of agreement between the model and the input data.
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Spolupráce turbodmychadla a spalovacího motoru
Vondrák, Adam ; Beran, Martin (oponent) ; Svída, David (vedoucí práce)
Práce se zabývá rozborem problematiky přiřazení turbodmychadla spalovacímu motoru a aspekty jejich vzájemné spolupráce. Vedle metodiky analytického stanovení velikosti potřebného kompresorového a turbínového stupně je zpracován také termodynamický model přeplňovaného jednoválcového motoru, který bude využit k pohonu prototypového monopostu pro soutěž Formula Student. Měřením provozních charakteristik na motorové brzdě byl vytvořen soubor experimentálních dat, jejichž zpracování umožnilo validaci termodynamického modelu a hlubší pochopení procesů probíhajících uvnitř celého systému.
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Exhaust Gas Energy Recuperation in a Commercial Vehicle Diesel Engine
Šroba, Roman ; Janoušek, Michal (oponent) ; Vondrák, Adam (vedoucí práce)
The scope of this thesis investigates value added by a turbocharger with an associated motor-generator unit to a diesel engine used by a commercial vehicle. A thermodynamic model of the engine was prepared in GT-SUITE software. Case studies were primary focused on a reduction of specific fuel consumption as well as a nitrogen oxides production using an energy recuperation of exhaust gas. Furthermore, there are described potential benefits of using an electric assistance in order to increase an exhaust gas temperature during a steady state engine operation. Additionally, there is an investigation of potential benefits of a turbocharger assistance in a transition engine mode operating during rapid acceleration of the vehicle. The results of individual analysis will be taken into account for a selection of turbocharger regarding specific engine implementation. The results of simulation suggest that it is possible to lower specific fuel consumption, production of nitrogen oxides, as well as accelerate turbocharger response.
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Turbocharger Performance Measurement
Ušiak, Michal ; Janoušek, Michal (oponent) ; Vondrák, Adam (vedoucí práce)
The bachelor’s thesis deals with recent methods of measuring turbocharger characteristics. Besides an introduction to fundamental performance characteristics, such as compressor map and turbine map, thesis contains description of experimental methods of collecting such data, which is essential for designing a turbocharged power unit. Description of main parts of the test stands and limitations consequent upon the measuring methods is supposed to offer basic knowledge of turbocharger design validation to the reader. As an extension overview of tests increasing accuracy of these characteristics and a few additional and safety tests is presented. Examples of use of these characteristics in engineering calculations should give an image of significance of creating computational model from experimental collected data, which describes thermodynamics of the turbocharger.
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Výpočtová studie Millerova cyklu benzínového motoru s turbodmychadlem
Černý, Roman ; Janoušek, Michal (oponent) ; Vondrák, Adam (vedoucí práce)
Práce se zabývá rozborem problematiky Millerova oběhu a jeho praktickou aplikací pro přeplňovaný zážehový motor. Na základě citlivostní analýzy limitů ovlivňujících tepelnou účinnost Millerova ideálního oběhu je zpracován termodynamický model motoru s prodlouženou expanzí v prostředí programu GT-POWER. Výsledky analýz jsou použity k vyhodnocení proveditelnosti přestavby referenčního motoru pro provoz s Millerovým oběhem.
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Fitting and Extrapolation of Turbocharger Turbine Maps
Vondrák, Adam ; Babák, Martin (oponent) ; Novotný, Pavel (oponent) ; Štětina, Josef (vedoucí práce)
Modelling of turbine performance is a prerequisite for detailed simulation of gas exchange in turbocharged combustion engines. At the same time, the possibility to determine efficiency and mass flow capacity at arbitrary operating points is key to comparing different turbine stages. The objective of this work is to propose a single method for both purposes, so it is possible to do the comparison using exactly the same turbine performance model as in subsequent engine working cycle simulation. The source of input data is typically a gas stand measurement, which enables capturing of limited turbine operating range only. In this work, methods are proposed to improve the fidelity and robustness of turbine performance extrapolation, while optimization is employed to find the best fit in terms of agreement between the model and the input data.
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Comparison of Hybrid Powertrain Topologies in Daily Commuting Regime
Ušiak, Michal ; Štětina, Josef (oponent) ; Vondrák, Adam (vedoucí práce)
The master’s thesis deals with modelling of various architectures of hybrid powertrains for three vehicle sizes in GT-SUITE and compares them in daily commuting operating mode. On top of making of the hybrid vehicle simulation models, control algorithms had to be created to manage the energy split between the internal combustion engine and the electric motor for each of the architectures. Routes to work and back were logged using the GPS and postprocessed to obtain the speed and the road grade profiles. Resulting data was used as an input in simulations of daily commuting. To compare all hybrid powertrain architectures, fuel economy and electricity consumption were evaluated for WLTP and daily commuting operating modes. Finally, the environmental impact of each topology was assessed based on an estimation of corresponding well-to-wheel emissions.
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Exhaust Gas Energy Recuperation in a Commercial Vehicle Diesel Engine
Šroba, Roman ; Janoušek, Michal (oponent) ; Vondrák, Adam (vedoucí práce)
The scope of this thesis investigates value added by a turbocharger with an associated motor-generator unit to a diesel engine used by a commercial vehicle. A thermodynamic model of the engine was prepared in GT-SUITE software. Case studies were primary focused on a reduction of specific fuel consumption as well as a nitrogen oxides production using an energy recuperation of exhaust gas. Furthermore, there are described potential benefits of using an electric assistance in order to increase an exhaust gas temperature during a steady state engine operation. Additionally, there is an investigation of potential benefits of a turbocharger assistance in a transition engine mode operating during rapid acceleration of the vehicle. The results of individual analysis will be taken into account for a selection of turbocharger regarding specific engine implementation. The results of simulation suggest that it is possible to lower specific fuel consumption, production of nitrogen oxides, as well as accelerate turbocharger response.
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