• Login
    View Item 
    •   Home
    • Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of KAUSTCommunitiesIssue DateSubmit DateThis CollectionIssue DateSubmit Date

    My Account

    Login

    Quick Links

    Open Access PolicyORCID LibguidePlumX LibguideSubmit an Item

    Statistics

    Display statistics

    Multiple Injector Concepts for Compression Ignition Engines - Experimental and computational work for lower heat losses, increased efficiency and improved combustion control

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Thesis_Nyrenstedt_updated_final.pdf
    Size:
    33.54Mb
    Format:
    PDF
    Description:
    Thesis Gustav
    Download
    Type
    Dissertation
    Authors
    Nyrenstedt, Gustav cc
    Advisors
    Johansson, Bengt cc
    Committee members
    Im, Hong G. cc
    Keyes, David E. cc
    koopmans, lucien
    Program
    Mechanical Engineering
    KAUST Department
    Physical Science and Engineering (PSE) Division
    Date
    2020-05
    Permanent link to this record
    http://hdl.handle.net/10754/664901
    
    Metadata
    Show full item record
    Abstract
    Several modern marine engines use multiple injectors for lower heat losses and higher efficiency. However, the heavy-duty vehicles still apply a single injector per cylinder. This work investigates how multiple injectors can be operated in compression ignition heavy-duty engines along with potential benefits from such concepts. The studies aimed to avoid high boundary gas temperatures by having two injectors at the rim of the bowl, in addition to the standard injector. A longer injector-wall distance reduces the amount of hot gases at the boundaries for reduced convective heat losses. Additional degrees of freedom also follows from an increased number of injectors to simplify combustion control. The thesis included CFD simulations, metal engine experiments, and optical engine diagnostics to investigate the efficiency –and emission benefits for two –and three-injector concepts compared to the single-injector approach. The CFD simulations aimed to set beneficial spray angles and chamber geometries for reduced heat losses and reasonable emission levels with and without swirl at different load conditions. A flat bowl with two injectors reduced the heat losses by 4.2 %-points resulting in a direct efficiency increase of 1.9 %-points at middle-load conditions. Metal engine studies confirmed the simulation results by testing two -and three-injector concepts. The higher three-injector flow rate raised efficiency and diminished heat losses while providing low nitric oxide levels. Thus, three injectors lessen the typical trade-off between efficiency and nitric oxides. The thesis further performed single-injector optical engine experiments to investigate combustion control limitations. The results concluded that high soot levels occur from the multiple injections used to achieve isobaric combustion. These high soot levels followed by injecting into fuel-rich zones, which can be avoided by using multiple injectors. Finally, the thesis provides a multiple injector design suitable for heavy-duty production engines.
    Citation
    Nyrenstedt, G. (2020). Multiple Injector Concepts for Compression Ignition Engines - Experimental and computational work for lower heat losses, increased efficiency and improved combustion control. KAUST Research Repository. https://doi.org/10.25781/KAUST-35UP9
    DOI
    10.25781/KAUST-35UP9
    ae974a485f413a2113503eed53cd6c53
    10.25781/KAUST-35UP9
    Scopus Count
    Collections
    Dissertations; Physical Science and Engineering (PSE) Division; Mechanical Engineering Program

    entitlement

     
    DSpace software copyright © 2002-2021  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service hosted by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items. For anonymous users the allowed maximum amount is 50 search results.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.