Sökning: "SI engines"

Visar resultat 1 - 5 av 62 avhandlingar innehållade orden SI engines.

1. 1. Alternative Combustion Strategies for Gasoline Engines

   Författare :Daniel Dahl; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; engines; SI; SGDI; CAI; HCCI; Otto; lean burn; gasoline; combustion; fuel consumption;

   Sammanfattning : Due to increasingly strict legislative demands and customer concerns regarding CO2emissions, there is a need to develop and implement new combustion strategies forgasoline (Otto) engines. In attempts to meet this need, most attention is focusing onthe low load/speed range where the classic spark ignition strategy (SI) has poorefficiency, mainly due to the throttling of the intake air causing pumping losses. LÄS MER

3. 2. 1-D simulation of turbocharged SI engines : focusing on a new gas exchange system and knock prediction

   Författare :Christel Elmqvist-Möller; Hans-Erik Ångström; Daniel Håkansson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spark ignited engines; 1-D flow simulation; knock; Divided Exhaust Period; turbocharged engines; Other engineering mechanics; Övrig teknisk mekanik;

   Sammanfattning : This licentiate thesis concerns one dimensional flow simulation of turbocharged spark ignited engines. The objective has been to contribute to the improvement of turbocharged SI engines’ performance as well as 1 D simulation capabilities. Turbocharged engines suffer from poor gas exchange due to the high exhaust pressure created by the turbine. LÄS MER

4. 3. Empirical combustion modeling in SI engines

   Författare :Fredrik Lindström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spark ignited engines; combustion modeling; knock; 1D simulation; Wiebe; divided exhaust period; Engineering mechanics; Teknisk mekanik;

   Sammanfattning : This licentiate thesis concerns the modeling of spark ignition engine combustion for use in one dimensional simulation tools. Modeling of knock is of particular interest when modeling turbocharged engines since knock usually limits the possible engine output at high load. LÄS MER

5. 4. Emission and Deposit Formation in Direct Injection Stratified Charge SI Engines

   Författare :Håkan Sandquist; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; cycle-resolved measurements; deposit formation; direct injection; stratified charge; hydrocarbon emissions; SI engines; fuels;

   Sammanfattning : A promising approach to increase the efficiency of the spark ignition (SI) engine is to inject the fuel directly into the cylinder to form a stratified charge. There is a potential to reduce the fuel consumption at low speeds and loads by 20 - 25% compared with conventional SI engines with stoichiometric homogeneous charge. LÄS MER

7. 5. Lean Homogeneous combustion for SI-Engines

   Författare :Gerben Doornbos; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lean homogeneous combustion; lean limit.; Dual Coil Ignition; ammonia formation catalyst; valve-timing;

   Sammanfattning : This thesis is about the application of lean homogeneous combustion in SI engines using a passive SCR after treatment system. By implementing this concept a decrease in fuel consumption and engine out NOx is expected. The data and results are obtained through engine experiments. LÄS MER