Sökning: "auto-ignition"

Visar resultat 16 - 20 av 38 avhandlingar innehållade ordet auto-ignition.

  1. 16. 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

  3. 17. CFD Modelling of a Free-Piston Engine Using Detailed Chemistry

    Författare :Miriam Bergman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; free-piston; combustion; Diesel; compression ignition; chemical kinetics; HCCI; Computational Fluid Dynamics;

    Sammanfattning : The Free Piston Engine, FPE, which is capable of operating in a variable compression ratio mode, is highly suitable for the promising Homogeneous Charge Compression Ignition (HCCI) concept, allowing flexible auto-ignition control on a cycle-to-cycle basis without any hardware modifications. In this study, the effects of varying the start of injection on the emission formation and efficiency of such an engine have been investigated, using simulations based on the KIVA-3V CFD code. LÄS MER

  4. 18. Homogeneous Ignition - Chemical Kinetic Studies for IC-Engine Applications

    Författare :Per Amnéus; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Skeletal mechanism; Mechanism reduction; n-heptane; iso-octane; formaldehyde; methane; Motors and propulsion systems; Motorer; framdrivningssystem; Physics; Fysik; Detailed chemistry; Kinetic calculations; Engine knock; Homogeneous charge compression ignition; HCCI; Fysicumarkivet A:2002:Amnéus;

    Sammanfattning : Calculations on a Homogeneous Charge Compression Ignition (HCCI) engine have been performed. Zero-dimensional models were used. The simplest model compressed the gas to auto-ignition, using temperature and pressure at a certain crank angle position obtained from engine experiments. LÄS MER

  5. 19. Combustion characteristics of some alternative fuels in ICE: : a detailed numerical study

    Författare :Siyuan Hu; Strömningsteknik; []
    Nyckelord :Combustion; duel fuel; methane; hydrogen; nheptane; methanol; DNS; simulation; openFoam; mixture-averaged; RCCI; ignition wave;

    Sammanfattning : Two major fuels commonly used in compression ignition (CI) and spark ignition (SI) enginesare diesel and gasoline. The reserve of diesel and gasoline is limited, however the combustion ofthese fuels giving rise to air pollution. LÄS MER

  7. 20. Kinetic modelling of autoignition phenomena

    Författare :David Johansson; Pehr Björnbom; Johan Andrae; Ulf Henriksson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical engineering; Kemiteknik;

    Sammanfattning : To fully understand the elementary reactions behind the ignition of automotive fuels the interaction between the fuel components must be known. The ignition initiation is most often caused by loss of an H radical from a reactive fuel molecule, for example n-heptane. The formed alkyl radical is prone to react with oxygen under lean conditions. LÄS MER