Sökning: "Piston Motion"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden Piston Motion.

1. 1. On the Impact of Piston Motion and In-Cylinder Charge Composition on Energy Release, Auto Ignition and Emission Formation in Premixed Charge Internal Combustion Engines

   Författare :Ola Stenlåås; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bränslen; sprängämnen; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; Internal Combustion Engine; Emission; SI; Spark Ignition; HCCI; Homogeneous Charge Compression Ignition; zone model; Chemical Kinetic; Engine simulation; Reformed Methanol; Hydrogen; Knock; Auto Ignition; NO; Piston Motion; Nitric Oxide; Premixed Charge;

   Sammanfattning : The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model. Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. LÄS MER

3. 2. A mechanical model of an axial piston machine

   Författare :Rasmus Löfstrand Grip; Ulf Sellgren; Niclas Strömberg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multi-body mechanical model; axial piston; Z-shaft; wobble plate; Sophia; Engineering mechanics; Teknisk mekanik;

   Sammanfattning : A mechanical model of an axial piston-type machine with a so-called wobble plate and Z-shaft mechanism is presented. The overall aim is to design and construct an oil-free piston expander demonstrator as a first step to realizing an advanced and compact small-scale steam engine system. LÄS MER

4. 3. 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

5. 4. 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

7. 5. 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