• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA 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 UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Finite element analysis of incompressible, compressible, and chemically reacting flows, with an emphasis on the pressure approximation.

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_9223558_sip1_c.pdf
    Size:
    9.745Mb
    Format:
    PDF
    Download
    Author
    Dyne, Barry Richard.
    Issue Date
    1992
    Keywords
    Dissertations, Academic.
    Mechanical engineering.
    Advisor
    Heinrich, Juan C.
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    A finite element numerical method is developed for the modelling of compressible flows with locally incompressible regions, which avoids the pressure oscillations frequently exhibited in these areas. Unification of the modelling of pressure in the finite element approximation of compressible and incompressible flows is investigated through the appropriate combinations of approximation spaces and integration schemes. The penalty method for incompressible flows is re-examined in the context of a slightly compressible fluid, yielding a formulation that is consistent for both the Navier-Stokes and Stokes equations, and providing an accurate method for calculation of pressure that is faster than the solution of a pressure Poisson equation. Extension of concepts from the reformulated penalty method to the compressible Navier-Stokes equations leads to an algorithm using piecewise constant density and pressure, with bilinear velocity and temperature. Further investigation shows that bilinear density with selective reduced integration also avoids pressure oscillations, while providing improved shock capture. Selective reduced integration of all terms related to compressibility is shown to be a key element in the avoidance of pressure oscillations. The identification of the isotropic component of the stress tensor as a compressibility term, not to be combined with viscous terms, is emphasized. Reduced integration of divergence terms is shown to yield conservation of mass on the element level as well as on the assembled level, whereas full integration conserves mass only on the assembled level. The compressible flow algorithm is coupled with a chemistry solver, for the study of chemically reacting flows, where an oscillation free flow solution is essential since unphysical oscillations may cause premature ignition. Computational efficiency is obtained by iterating a fluid flow step with frozen chemistry, and a chemical reaction step with frozen flow. The algorithm is applied to the study of the ram accelerator concept, a technique for accelerating a projectile in a tube to extremely high velocities by using a shock wave to initiate combustion. The viability of the ram accelerator is demonstrated through calculations at various velocities, pressures, and gas mixtures.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Aerospace and Mechanical Engineering
    Graduate College
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    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.