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Showing result 1 - 5 of 8 swedish dissertations matching the above criteria.

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

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

   Abstract : 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. READ MORE

4. 2. Gas-Diesel Dual-Fuel Combustion in a Heavy-Duty Engine

   Author : Zhiqin Jia; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : Global efforts have been devoted to developing different kinds of alternative fuels in order to reduce the dependence on conventional petroleum fuels. Among these alternative fuels, the compressed natural gas (CNG) is a pop- ular choice because of its relatively clean combustion and global availability at attractive prices. READ MORE

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

   Author : Miriam Bergman; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 4. Modeling of a Free Piston Energy Converter

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

   Abstract : 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. READ MORE

7. 5. Numerical Modelling of Fuel Sprays

   Author : Christer Bergström; Strömningsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; Gas turbine.; Temperature fluctuations. Diesel engine; Counter rotating Vortex Pair; CVP; Large Eddy Simulation; Droplet Evaporation; Turbulent flows; LES; Spray; Modelling; Break-up; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; bränslen; sprängämnen;

   Abstract : The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction beween the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. READ MORE