Sökning: "SI engine"

Visar resultat 1 - 5 av 73 avhandlingar innehållade orden SI engine.

1. 1. Development of Zonal Models for Analysis of Engine Knock

   Författare :Shahrokh Hajireza; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; homogeneous autoignition; engine knock; Zonal modeling; SI engine; hot-spot autoignition; exothermic centers; wall heat transfer; application of detailed chemical kinetic mechanism of n-heptane and iso-octane; Motors and propulsion systems; Motorer; framdrivningssystem;

   Sammanfattning : Autoignition in SI engines is an abnormal combustion mode and may lead to engine knock which is an undesired phenomenon in SI engines. It may cause damage and it is a source of noise in engines. Knock limits the compression ratio of the engine and a low compression ratio means low fuel conversion efficiency of the engine. LÄS MER

3. 2. Chemistry of Combustion Products Investigation of Combustion Chamber Deposits Formed in a Gasoline Direct Injection Stratified Charge SI Engine

   Författare :Farshid Owrang; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gasoline fuels; SI engine; gasoline direct injection; stratified charge; combustion chamber deposits; engine oil; oxidation; in situ measurement; thermal desorption; GC MS; fast neutron activation analysis; spin-lattice relaxation constant; NMR;

   Sammanfattning : The aim of this work was to characterize deposits formed in the combustion chambers of a gasoline direct injection stratified charge SI engine. The engine was run with several types of gasoline fuels and a special reference engine oil. LÄS MER

4. 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

   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

5. 4. HCCI Combustion - Engine Operation and Emission Characteristics

   Författare :Magnus Christensen; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Motorer; framdrivningssystem; Motors and propulsion systems; efficiency; emissions; combustion; HCCI; engine;

   Sammanfattning : The potential and limitations of the Homogeneous Charge Compression Ignition (HCCI) engine concept has been experimentally investigated. The operation range, in terms of usable air/fuel ratio and engine load, and the emission characteristics have been studied. An 1. LÄS MER

7. 5. 1D engine simulation of a turbocharged SI engine with CFD computation on components

   Författare :Ulrica Renberg; Hans-Erik Ångström; Laszlo Fuchs; Per Birkestad; KTH; []
   Nyckelord :1D modeling; CFD modeling; turbine efficiency; pipe flow; turbocharged engine; TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : Techniques that can increase the SI- engine efficiency while keeping the emissions very low is to reduce the engine displacement volume combined with a charging system. Advanced systems are needed for an effective boosting of the engine and today 1D engine simulation tools are often used for their optimization. LÄS MER