Sökning: "In-cylinder flow"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden In-cylinder flow.

1. 1. Creation and destruction of in-cylinder flows : Large eddy simulations of the intake and the compression strokes

   Författare :Martin Söder; Laszlo Fuchs; Angelo Onorati; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Swirl; Tumble; Compression; Engine; LES; CFD; engine turbulence; engine simulations; intake flow structures; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The aim of this thesis is to increase engine efficiency by studying the flow structures created in an engine cylinder during the intake phase and the effect of the subsequent compression.The invention of the combustion engine has enabled three centuries of economic growth fueled by energy stored as hydrocarbons. LÄS MER

3. 2. Investigation of Partially Premixed Combustion in an Optical Engine : In-Cylinder Flow and Combustion Characterization

   Författare :Slavey Tanov; Förbränningsmotorer; []
   Nyckelord :PPC; in-cylinder flow structures; Combustion diagnostics; Gasoline; Gasoline-Ethanol; Multiple Injection; Stratification Level;

   Sammanfattning : The diesel engine is one of the most economic power sources and is therefore used in a range of technical solutions. The low fuel consumption combined with high engine performance makes it attractive for transportation vehicles. LÄS MER

4. 3. Large Eddy Simulation of Turbulent Flow and Combustion in HCCI Engines

   Författare :Rixin Yu; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent combustion; Numerical methods.; LES; Temperature inhomogeneity; HCCI combustion; In-cylinder flow;

   Sammanfattning : This thesis deals with numerical simulations of the turbulent combustion process in Homogeneous Charge Compression Ignition (HCCI) engines. An accurate and computationally efficient Large Eddy Simulation (LES) model was developed and used throughout this thesis to investigate the development of in-cylinder turbulence, temperature stratification, onset of auto-ignition, and development of the reaction fronts. LÄS MER

5. 4. In-cylinder Flow Characterisation of Heavy Duty Diesel Engines Using Combustion Image Velocimetry

   Författare :Henrik Dembinski; Hans-Erik Ångström; Werner Hentschel; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : In-cylinder flow in diesel engines has a large impact on combustion and emission formation. In this work, the flow is characterised with a new measurement method called combustion image velocimetry (CIV). LÄS MER

7. 5. In-Cylinder Fluid Flow, Fuel Preparation and Combustion in SI Engines - Application of Optical Diagnostics

   Författare :Martin Ekenberg; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laserteknik; vakuumteknik; vibrationer; akustik; Motors and propulsion systems; Motorer; hydraulik; Maskinteknik; PIV; vibration and acoustic engineering; hydraulics; vacuum technology; Mechanical engineering; framdrivningssystem; Laser technology;

   Sammanfattning : In this thesis laser-based measurements of in-cylinder flow and fuel concentrations in two stroke and direct injected four-stroke engines are presented. The major problem with the carburetted two-stroke engine is the short-circuiting of fuel that occurs during the scavenging phase. This leads to large emissions of unburned hydrocarbons. LÄS MER