Sökning: "Spark Ignition"

Visar resultat 21 - 25 av 77 avhandlingar innehållade orden Spark Ignition.

1. 21. Variable Valve Actuation in a Spark Ignition Engine - A Flow Field and Heat Release Study

   Författare :Fredrik Söderberg; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; framdrivningssystem; Gases; plasma; fluid dynamics; plasmas; Gaser; fluiddynamik; vakuumteknik; vibrationer; akustik; Motors and propulsion systems; Motorer; hydraulik; Maskinteknik; vibration and acoustic engineering; Laser Doppler Velocimetry Particle Image Velocimetry PIV LDV Wavelet Computational Fluid Dynamics CFD Variable Valve Actuation Timing Turbulence Combustion Engine Spark Ignition Miller; hydraulics; vacuum technology; Mechanical engineering;

   Sammanfattning : The objective of this thesis was to find ways of improving part-load efficiency for a spark ignition engine by studying the effects of variable-valve actuation on fluid flow and combustion. The in-cylinder flow was measured with laser doppler velocimetry, LDV, and particle image velocimetry, PIV. LÄS MER

3. 22. An Experimental Study of a Spark-assisted

   Författare :Andreas Berntsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Future requirements for reductions in fuel consumption and emissions from ground vehicles might be met by using the HCCI combustion concept, in which a more or less homogenous air fuel mixture is compressed to auto-ignition. This consumes less fuel than normal SI combustion and its ability to burn lean mixtures at low temperatures has a positive impact on exhaust emissions. LÄS MER

4. 23. Full Cycle Engine Simulations with Detailed Chemistry

   Författare :Adina Gogan; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; plasmas; Gaser; Gases; fluid dynamics; aktuariematematik; programmering; operationsanalys; Statistik; actuarial mathematics; programming; operations research; Statistics; detailed kinetics; emissions; engine knock; autoignition; modeling; spark ignition engine; diesel engine; fluiddynamik; plasma; Technological sciences; Teknik; Thermal engineering; applied thermodynamics; Termisk teknik; termodynamik; Motors and propulsion systems; Motorer; framdrivningssystem; stochastic reactor model;

   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. 24. Impact of Fuel Properties on Partially Premixed Combustion

   Författare :Hadeel Solaka; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PPC; Reference Fuels; Gasline; Diesel; Ignition Delay; Quadratic Regression Model;

   Sammanfattning : Compression ignited engines generally have higher efficiency than spark ignition engines. However, the most common combustion concept in compression ignited engines, conventional diesel combustion, struggles with high levels of particulate matter and NOx emissions. LÄS MER

7. 25. Studies on the Load Range of an HCCI Engine using In-Cylinder Pressure, Ion Current and Optical Diagnostics

   Författare :Andreas Vressner; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ion current; knock; laser ignition; chemiluminescence imaging; LES; temperature stratification; PLIF; auto igntion; flame propagation; HCCI; diagnostics; low temperature combustion;

   Sammanfattning : Internal combustion engines are continuously developed towards decreased hazardous emissions and lower fuel consumption. The homogeneous charge compression ignition (HCCI) engine is a promising concept which combines the best features of the Diesel engine and the spark ignition (SI) engine. LÄS MER