Sökning: "reaction zone structure"

Visar resultat 1 - 5 av 20 avhandlingar innehållade orden reaction zone structure.

  1. 1. Numerical Modeling of Soot and NOx Formation in Non-Stationary Diesel Flames with Complex Chemistry

    Författare :Feng Tao; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; soot and NOx formation; non-stationary Diesel sprays; complex chemistry; Diesel spray auto-ignition; reaction zone structure; Diesel flame liftoff; turbulence-chemistry interaction;

    Sammanfattning : A complex chemistry model of reduced size (65 species and 268 reactions) derived on the basis of n-heptane auto-ignition kinetics, small hydrocarbon oxidation chemistry, polyaromatic hydrocarbon (PAH) and NOx formation kinetics together with a phenomenological soot model has been implemented in the KIVA code for multidimensional Diesel spray combustion simulations. An EDC (Eddy Dissipation Concept) based partially stirred reactor model is used to handle the turbulence-chemistry interaction. LÄS MER

  2. 2. Advanced Laser-based Multi-scalar Imaging for Flame Structure Visualization towards a Deepened Understanding of Premixed Turbulent Combustion

    Författare :Bo Zhou; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laser Diagnostics; PLIF; High Spatial Resolution; Multi-scalar Instantaneous Visualization; HCO CH Radicals; Distributed Reaction Zone; Mild Combustion.; Combustion Regimes; Turbulence Flame Interaction; Turbulent Premixed Combustion; Fysicumarkivet A:2015:Zhou;

    Sammanfattning : The work presented in the thesis concerns the developments of laser-based diagnostics and its application to the study of turbulent premixed combustion. The diagnostic developments, mainly concerned with planar laser-induced fluorescence (PLIF), are intended to provide instantaneous visualization of the key species originating from the combustion processes involved in the burning of hydrocarbons and nitrogen-containing fuels under turbulent conditions. LÄS MER

  3. 3. Experimental investigation of premixed ammonia combustion at high Karlovitz number conditions

    Författare :Qingshuang Fan; Förbränningsfysik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent premixed combustion; Ammonia flames; Laser diagnostics; Flame structure; High Karlovitz number; Turbulent burning velocity; Fysicumarkivet A:2021:Fan;

    Sammanfattning : This thesis aims to acquire deep knowledge on turbulent premixed combustion at high Karlovitz (Ka) number conditions with the help of laser-based diagnostic measurements.Considering that ammonia (NH3), as a carbon-free energy carrier, is a promising candidate for replacing conventional fossil fuels in the future, all the investigations in this work were carried out on ammonia/air premixed flames. LÄS MER

  4. 4. Direct numerical simulation of turbulent premixed flames at high Karlovitz numbers: structure and modelling

    Författare :Thommie Nilsson; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct numerical simulation; Computational fluid dynamics; Combustion model; Premixed flame; Turbulence; Karlovitz number;

    Sammanfattning : There has been recent increased interest in premixed flames and in particular for use in gas turbines for power generation. This is a development that follows from increasing demands for high efficiency and low emissions of NOx, which can be achieved by using premixed flames and lean pre-heated mixtures, often close to the lean flammability limit. LÄS MER

  5. 5. Large Eddy Simulation of Turbulent Reactive Flows under HCCI Engine Conditions

    Författare :Tobias Joelsson; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Large Eddy Simulation (LES) modeling is developed to study homogeneous charge compression ignition (HCCI) combustion under different engine operation and mixture conditions, including real engine configurations and generic test cases. A previously developed HCCI model has been validated by comparing the simulation results with engine experiments. LÄS MER