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Visar resultat 1 - 5 av 11 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. CFD Modelling of a Free-Piston Engine Using Detailed Chemistry

    Författare :Miriam Bergman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; free-piston; combustion; Diesel; compression ignition; chemical kinetics; HCCI; Computational Fluid Dynamics;

    Sammanfattning : The Free Piston Engine, FPE, which is capable of operating in a variable compression ratio mode, is highly suitable for the promising Homogeneous Charge Compression Ignition (HCCI) concept, allowing flexible auto-ignition control on a cycle-to-cycle basis without any hardware modifications. In this study, the effects of varying the start of injection on the emission formation and efficiency of such an engine have been investigated, using simulations based on the KIVA-3V CFD code. LÄS MER

  3. 2. Modeling of a Free Piston Energy Converter

    Författare :Jakob Fredriksson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Free piston engine; detailed chemistry; variable compression; computational fluid dynamics CFD ; combustion;

    Sammanfattning : ABSTRACTThe Free Piston Energy Converter (FPEC) is a new type of automotive prime mover, offering high efficiency in conjunction with low emissions. The FPEC essentially consists of two opposing cylinders with a linear alternator incorporated in-between that produces electric power directly. LÄS MER

  4. 3. CFD-based Analysis of Combustion Processes in a Free-Piston Diesel Engine

    Författare :Miriam Bergman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; chemical kinetics; Diesel; homogeneous charge compression ignition HCCI ; free-piston; equivalence ratio vs. temperature maps; computational fluid dynamics CFD ; surrogate fuel;

    Sammanfattning : The Free Piston Engine (FPE) which is capable of operating in a variable compression ratio mode, allows flexible auto-ignition control on a cycle-to-cycle basis without any hardware modifications. In this study combustion processes in an FPE were examined using the KIVA-3V CFD code with detailed chemical kinetics (305 reactions among 70 species) of a Diesel surrogate fuel incorporated. LÄS MER

  5. 4. Analysis and control of a hybrid vehicle powered by free-piston energy converter

    Författare :Jörgen Hansson; Mats Leksell; Chandur Sadarangani; Anders Malmquist; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; free-piston energy converter; FPEC; series hybrid electric vehicle; SHEV; power management; energy management; powertrain evaluation; equivalent consumption minimisation; ECMS; linear engine; Electrical engineering; Elektroteknik;

    Sammanfattning : The introduction of hybrid powertrains has made it possible to utilise unconventional engines as primary power units in vehicles. The free-piston energy converter (FPEC) is such an engine. It is a combination of a free-piston combustion engine and a linear electrical machine. LÄS MER

  7. 5. Optical Diagnostics for Engine Efficiency in Gasoline Compression Ignition

    Författare :Miao Zhang; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PPC; Optical engine; Engine Eciency; Multiple-injection strategies; Thermodynamic analysis;

    Sammanfattning : The internal combustion engine has played a significant role in a vast number of applications from small cars to giant tankers, setting people free from geographical barriers and heavy labor. However, it has also generated many tons of harmful emissions and CO2that damage to humans and the environment. LÄS MER