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Comparison of Hybrid Powertrain Topologies in Daily Commuting Regime
Ušiak, Michal ; Štětina, Josef (referee) ; Vondrák, Adam (advisor)
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 (referee) ; Novotný, Pavel (referee) ; Štětina, Josef (advisor)
Modelování turbínových charakteristik je nutným předpokladem pro detailní simulaci výměny náplně válce turbodmychadlem přeplňovaných spalovacích motorů. Kromě toho je možnost stanovení účinnosti a průtokové kapacity v libovolných pracovních bodech klíčová pro porovnání různých turbínových stupňů. Cílem této práce je předložit jednotnou metodu pro oba účely tak, aby bylo možné provést porovnání použitím přesně stejných modelů turbín jako při následné simulaci pracovního oběhu motoru. Zdrojem vstupních dat je obvykle měření na plynové zkušebně, které však umožňuje zachycení pouze omezeného pracovního rozsahu turbíny. V této práci jsou navrženy metody umožňující zvýšení věrohodnosti a robustnosti extrapolace turbínových charakteristik, přičemž optimalizace je využita k určení takových parametrů hledaných funkcí, které vedou k nejlepší shodě mezi modelem a vstupními daty.
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Matching of a Turbocharger to a Combustion Engine
Vondrák, Adam ; Beran, Martin (referee) ; Svída, David (advisor)
The master’s thesis deals with methods of matching of a turbocharger to a combustion engine and with the analysis of their mutual cooperation. Besides a methodology of analytical determination of the appropriate size for compressor and turbine stage, there was created a thermodynamic model of an engine that is to be used as a means of propulsion for a prototype single-seater for the competition Formula Student. Post processing of real engine data measured on a dyno helped to create a parameter database that could be used for validation of the thermodynamic engine model and for deeper understanding of the system’s internal processes.
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Exhaust Gas Energy Recuperation in a Commercial Vehicle Diesel Engine
Šroba, Roman ; Janoušek, Michal (referee) ; Vondrák, Adam (advisor)
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 (referee) ; Vondrák, Adam (advisor)
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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Computational Study of the Miller Cycle on a Gasoline Engine with a Turbocharger
Černý, Roman ; Janoušek, Michal (referee) ; Vondrák, Adam (advisor)
The scope of this thesis is the Miller engine cycle analysis and its practical application on a turbocharged spark ignited engine. Based on the sensitivity analysis of the limits affecting the ideal Miller cycle thermal efficiency a thermodynamic model of the engine with a prolonged expansion was set up in the GT-POWER software. The results of the analyses were used to evaluate the feasibility of the reference engine conversion for an operation with Miller cycle.
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Fitting and Extrapolation of Turbocharger Turbine Maps
Vondrák, Adam ; Babák, Martin (referee) ; Novotný, Pavel (referee) ; Štětina, Josef (advisor)
Modelování turbínových charakteristik je nutným předpokladem pro detailní simulaci výměny náplně válce turbodmychadlem přeplňovaných spalovacích motorů. Kromě toho je možnost stanovení účinnosti a průtokové kapacity v libovolných pracovních bodech klíčová pro porovnání různých turbínových stupňů. Cílem této práce je předložit jednotnou metodu pro oba účely tak, aby bylo možné provést porovnání použitím přesně stejných modelů turbín jako při následné simulaci pracovního oběhu motoru. Zdrojem vstupních dat je obvykle měření na plynové zkušebně, které však umožňuje zachycení pouze omezeného pracovního rozsahu turbíny. V této práci jsou navrženy metody umožňující zvýšení věrohodnosti a robustnosti extrapolace turbínových charakteristik, přičemž optimalizace je využita k určení takových parametrů hledaných funkcí, které vedou k nejlepší shodě mezi modelem a vstupními daty.
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Comparison of Hybrid Powertrain Topologies in Daily Commuting Regime
Ušiak, Michal ; Štětina, Josef (referee) ; Vondrák, Adam (advisor)
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.
|
|
|
Exhaust Gas Energy Recuperation in a Commercial Vehicle Diesel Engine
Šroba, Roman ; Janoušek, Michal (referee) ; Vondrák, Adam (advisor)
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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