• Login
    View Item 
    •   Home
    • Theses & Dissertations
    • 2020 - Mines Theses & Dissertations
    • View Item
    •   Home
    • Theses & Dissertations
    • 2020 - Mines Theses & Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Mines RepositoryCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    Login

    Mines Links

    Arthur Lakes LibraryColorado School of Mines

    Statistics

    Display Statistics

    Heat transfer mechanisms in highly porous fibrous insulation from vacuum to high pressures--experiment and modeling

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Curran_mines_0052E_11951.pdf
    Size:
    7.397Mb
    Format:
    PDF
    Download
    Author
    Curran, David Jacob
    Advisor
    Porter, Jason M.
    Date issued
    2020
    Keywords
    heat transfer
    radiation
    natural convection
    fibrous insulation
    
    Metadata
    Show full item record
    URI
    https://hdl.handle.net/11124/174175
    Abstract
    Highly porous fibrous ceramics are widely used as insulating materials in thermal systems due to their high temperature limits and light weight. An experimental apparatus, using the radial flow method, has been developed to evaluate heat transfer in highly porous fibrous ceramic materials. The experimental apparatus is constructed and instrumented to evaluate an insulation specimen at pressure ranges from 0.005 < P < 30 bar of pressure and for temperatures ranging from 300 - 1273 K. The design, construction, and instrumentation of the experimental apparatus are reported as well as validation of thermal conductivity measurements to manufacturer data. Analysis of experiments conducted near vacuum and at atmospheric pressure provide valuable insight into the contributions of solid conduction and radiation heat transfer. In addition to experiments conducted at the Colorado School of Mines, tomographic reconstructions of sample insulation material were analyzed to determine fiber size and orientation distributions as well as tortuosity and volume fraction of the solid and pores. A combined radiation and conduction computational model was developed to calculate thermal conductivity in ceramic fiber materials using the Rosseland diffusion approximation to evaluate thermal radiation transfer, and a tortuosity-weighted effective thermal conductivity to evaluate gas and solid phase conduction. Experiments conducted at elevated pressures provide insight into natural convection effects in the highly porous media. Nusselt correlations based on the Darcy-Rayleigh number were fit to the data and demonstrate how insulation density and fiber orientation impact natural convection. Together, the conduction, radiation, and natural convection model, informed by tomographic reconstructions, can predict directional thermal conductivity of fibrous blanket material within 6% of measured values, providing a useful tool for manufacturers to identify critical parameters of ceramic fiber insulation manufacture and installation to maximize insulating properties.
    Rights
    Copyright of the original work is retained by the author.
    Collections
    2020 - Mines Theses & Dissertations

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    Open Repository is a service operated 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.

    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.