Sökning: "In-cylinder flow"

Visar resultat 6 - 10 av 25 avhandlingar innehållade orden In-cylinder flow.

1. 6. Laser Diagnostics of HCCI and Partially Premixed Combustion

   Författare :Leif Hildingsson; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low temperature combustion; Motorer; Motors and propulsion systems; Teknik; Technological sciences; PIV; in-cylinder flow structures; hydroxyl; OH; partially-oxidized fuel; formaldehyde; HCOH; LIF; diesel combustion; partially premixed combustion; PPC; HCCI; framdrivningssystem;

   Sammanfattning : The work presented in this thesis deals with measuring in-cylinder combustion species and events using different laser-based diagnostic methods. A variety of engine operating modes, like HCCI and partially premixed diesel combustion, have been investigated. LÄS MER

3. 7. 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

4. 8. Flow measurements using combustion image velocimetry in diesel engines

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

   Sammanfattning : This work shows the in-cylinder airflow, and its effects on combustion and emissions, in a modern, heavy-duty diesel engine. The in-cylinder airflow is examined experimentally in an optical engine and the flow field inside the cylinder is quantified and shown during combustion, crank angle resolved. LÄS MER

5. 9. 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

7. 10. Experimental Investigations of Combustion Chamber Heat Transfer in a Light-Duty Diesel Engine

   Författare :Jessica Dahlström; Förbränningsmotorer; []
   Nyckelord :internal combustion engines; heat transfer; diesel engine; Diesel combustion; combustion chamber geometry; piston geometry; spray parameters;

   Sammanfattning : This work concerned experimental studies of heat transfer in a light-duty diesel engine. Combustion is affected by several parameters, such as pressure, engine speed, mass of injected fuel and in-cylinder gas flow. These parameters are in turn affected by the combustion chamber geometry and fuel spray characteristics. LÄS MER