Sökning: "Motorer"

Visar resultat 16 - 20 av 81 avhandlingar innehållade ordet Motorer.

  1. 16. Study and Development of Techniques to Improve Engine Stability and Reduce Emissions from Natural Gas Engines

    Författare :Patrik Einewall; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; framdrivningssystem; Motorer; Motors and propulsion systems; Low Emissions ; Natural Gas Engines ; EGR ;

    Sammanfattning : The objective of this thesis was to find ways to improve combustion and reduce emissions from supercharged natural gas engines. In-cylinder flow measurements were made with laser doppler velocimetry, LDV, heat release was calculated from cylinder pressures and emissions were measured at various locations. LÄS MER

  3. 17. 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

  4. 18. CFD Modeling of Turbulent Flows in Industrial Applications with Emphasis on Premixed Combustion in Gas Turbines

    Författare :Ulf Engdar; Kraftverksteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; framdrivningssystem; Motorer; turbulence and premixed combustion modeling ; CFD modeling ; level-set flamelet library approach ; emissions ; gas turbine ; compressor washing ; spray modeling ; Technological sciences; Teknik; Energy research; Energiforskning; Thermal engineering; applied thermodynamics; Termisk teknik; Motors and propulsion systems; termodynamik;

    Sammanfattning : Increasing restrictions on hazardous emissions combined with demands for good profitability from the operators in the energy market have contributed strongly to the development of innovations in which the emphasis is on low emissions and high efficiency. For gas turbine-based power plants, emission of NOx in particular is governed by stringent legislation. LÄS MER

  5. 19. Development of a 2D Temperature Measurement Technique for Combustion Diagnostics using 2-Line Atomic Fluorescence

    Författare :Johan Engström; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laser technology; Elektronik och elektroteknik; Electronics and Electrical technology; PLIF; LIF; temperature measurements; TLAF; Laser diagnostic; combustion; Laserteknik; Motors and propulsion systems; Motorer; framdrivningssystem;

    Sammanfattning : The present thesis is concerned with the development and application of a novel planar laser-induced fluorescence (PLIF) technique for temperature measurements in a variety of combusting flows. Accurate measurement of temperature is an essential task in combustion diagnostics, since temperature is one of the most fundamental quantities for the characterization of combustion processes. LÄS MER

  7. 20. 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