Sökning: "Spark ignition engine"
Visar resultat 1 - 5 av 69 avhandlingar innehållade orden Spark ignition engine.
1. Experimental Studies of Advanced Ignition Systems for Lean Burn Natural Gas Engines
Sammanfattning : One of the greatest challenges for the transport sector today is reducing its environmental impact. This applies especially to the emission aspects, much due to increasingly stringent emissions legislations. LÄS MER
2. Theoretical and Experimental Studies of the Formation of Ionized Gases in Spark Ignition Engines
Sammanfattning : The processes that govern the formation, existence and consumption of ions in gases have been studied both experimentally and theoretically. The aim of the work is targeted at increasing the understanding of these phenomena in the working gases inside an engine. LÄS MER
3. 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
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
4. Full Cycle Engine Simulations with Detailed Chemistry
Sammanfattning : The modeling work developed in this thesis can be divided in two main areas of investigations: autoignition related to spark ignition engine and combustion and emissions formation in relation to diesel engines. A first version of a detailed kinetics engine simulation program, extended to handle full cycle calculations, was employed in order to demonstrate the strong effect that nitric oxide from the residual gas has on the autoignition onset. LÄS MER
5. Spark Ignition Combustion of Direct Injected Alternative Fuels
Sammanfattning : Several technologies and modifications exist to increase the fuel efficiency of passenger vehicles in general and spark ignition engines in particular. Combining a spark ignition engine with an electric drive system in hybrid powertrain and thermodynamic cycle improvements are two such approaches with the potential to greatly reduce fuel consumption. LÄS MER