Sökning: "two-phase flow"

Visar resultat 21 - 25 av 116 avhandlingar innehållade orden two-phase flow.

1. 21. Input Calibration, Code Validation and Surrogate Model Development for Analysis of Two-phase Circulation Instability and Core Relocation Phenomena

   Författare :Viet-Anh Phung; Pavel Kudinov; Cristophe Demaziere; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reactor system code; input calibration; code validation; surrogate model; two-phase circulation flow instability; in-vessel core relocation; genetic algorithm; artificial neural network; Reaktorsystemkod; indata kalibrering; kodvalidering; surrogatmodell; två-fas cirkulationsflöde; instabilitet; härdrelokering i reaktortanken; genetisk algoritm; artificiella neurala nätverk; Fysik; Physics;

   Sammanfattning : Code validation and uncertainty quantification are important tasks in nuclear reactor safety analysis. Code users have to deal with large number of uncertain parameters, complex multi-physics, multi-dimensional and multi-scale phenomena. LÄS MER

3. 22. Mathematical Modeling of Transport Phenomena in Polymer Electrolyte and Direct Methanol Fuel Cells

   Författare :Erik Birgersson; KTH; []
   Nyckelord :Fuel Cell; DMFC; PEFC; model; visual cell; scale analysis; one-phase; two-phase;

   Sammanfattning : This thesis deals with modeling of two types of fuel cells:the polymer electrolyte fuel cell (PEFC) and the directmethanol fuel cell (DMFC), for which we address four majorissues: a) mass transport limitations; b) water management(PEFC); c) gas management (DMFC); d) thermal management. Four models have been derived and studied for the PEFC,focusing on the cathode. LÄS MER

4. 23. Modelling and Simulation of Turbulent Gas-Solid Flows applied to Fluidization

   Författare :Eric Peirano; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Eulerian models; fluidization; two-fluid model; two-phase flow; granular flow theory; turbulence; fluidized beds; gas-solid flows;

   Sammanfattning : Modelling of gas-solid suspensions has been studied with emphasis on suitable closure laws. A study of characteristic time scales and energy dissipation mechanisms is made for the case of a simple shear flow. Applications of the modelling are presented in the form of simulation and validation of experiments in fluidized beds. LÄS MER

5. 24. Rapid wetting - influence of surface geometry and fluid properties

   Författare :Susumu Yada; Fredrik Lundell; Shervin Bagheri; Minh Do-Quang; Gustav Amberg; Jacco Snoeijer; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wetting; spreading; surface structures; droplet; contact line; two-phase flow; non-Newtonian flow; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : Wetting of a liquid on a solid surface is ubiquitous in everyday life, such as morning dew on a plant leaf and raindrops hitting on a glass window. However, this phenomenon is far away from being completely understood. LÄS MER

7. 25. On stability of solutions to the two-fuid models for dispersed two-phase flow

   Författare :Reymir Levi Gudmundsson; KTH; []
   Nyckelord :;

   Sammanfattning : In this thesis the two-fluid (Eulerian/Eulerian) formulationfor dispersed two-phase flow is considered. The inviscidformulation in one space dimension is known to be conditionallywell-posed. On the other hand the viscous formulation islocally in time well-posed for smooth initial data, but with amedium to high wave number instability. LÄS MER