• Medientyp: E-Book; Elektronische Hochschulschrift; Dissertation
  • Titel: Dynamical phase transitions in compressible media ; Dynamische Phasenübergänge in kompressiblen Medien
  • Beteiligte: Merkle, Christian [Verfasser:in]
  • Erschienen: University of Freiburg: FreiDok, 2006
  • Umfang: pdf
  • Sprache: Englisch
  • Schlagwörter: Numerische Strömungssimulation ; Online-Ressource ; Nichtlineares hyperbolisches System ; Finite-Volumen-Methode ; Computersimulation
  • Entstehung:
  • Anmerkungen: Diese Datenquelle enthält auch Bestandsnachweise, die nicht zu einem Volltext führen.
  • Beschreibung: The aim of this thesis is the investigation of liquid-vapor flows. Vapor together with liquid phases occurin many applications like cavitation problems, cooling and boiling processes or the breakup of liquid jets. Since e.g. turbine blades and ship propellers can bedestroyed by cavitation, this research is of high industrial interest. Both phases are transported by the flow and undergo phase transitions. The governing mathematical equations are expressed by the basic conservation laws for mass, momentum (and energy) together with suitable equations of state for all phases. Additionally, for the mass transfer across the phase boundaries special treatment is necessary. A very important issue of this thesis concerns the simultaneous treatment of phase transition and compressible flow. Up to now the dynamics of pure phase transition (Stefan problems, Cahn-Hilliard problem, Landau-Ginzburg equation, etc.) as well as the dynamics of compressible (viscous) flow have been studied very extensively but separately. The most basic experiment on liquid vapor flows considers the dynamics of a single vapor bubble in a container filled with liquid. If the outer pressure of the liquid is decreased to vapor pressure, then the liquid vapor interface starts to move: We have a dynamic phase boundary with mass transfer. In more complex settings this occurs during the process of cavitation. Lord Rayleigh discovered that pressure waves emitted during the process of cavitation near rigid walls may damage the walls. Mathematical models for liquid vapor phase transformations can be divided into two classes: diffuse interface models and sharp interface (SI) models. The first class takes into account the internal structure of a phase boundary and resolves it as a steep but continuous transition. In the second class phase boundaries are discontinuous transitions of the thermodynamical variables. In this thesis we are looking at the SI model and are dealing with the Euler equations together with a non monotone equation of state (e.g. ...
  • Zugangsstatus: Freier Zugang