Sökning: "Lagrangian bubble model"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Lagrangian bubble model.

1. 1. Numerical simulation and analysis of multi-scale cavitating flows using a hybrid mixture-bubble model

   Författare :Ebrahim Ghahramani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Homogeneous mixture model; Lagrangian bubble model; CFD; Cavitation; OpenFOAM; Multiphase flow; Hybrid model; Multi-scale;

   Sammanfattning : The aim of this research is to model and analyse multi-scale cavitating flows with a certain emphasis on small sub-grid vapour structures. Cavitating flows include vapour structures with different length scales, from micro-bubbles to large cavities. LÄS MER

3. 2. A Realizable Hybrid Mixture-Bubble Model for Cavitating Flows

   Författare :Ebrahim Ghahramani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multi-scale model; Homogeneous mixture model; Cavitation; Disperse multiphase flow; Eulerian-Lagrangian model; OpenFOAM;

   Sammanfattning : Cavitating multi-phase flows include an extensive range of cavity structures with different length scales, from micro bubbles to large sheet cavities that may fully cover the surface of a device. To avoid high computational expenses, incompressible transport equation models are considered a practical option for simulation of large scale cavitating flows, normally with limited representation of the small scale vapour structures. LÄS MER

4. 3. Numerical modeling of deforming bubble transport related to cavitating hydraulic turbines

   Författare :Daniel Lörstad; Institutionen för energivetenskaper; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gases; fluid dynamics; plasmas; Gaser; fluiddynamik; plasma; Energy research; Energiforskning; Direction Averaged Curvature DAC ; Direction Averaged Normal DAN ; Volume of Solid VOS ; Volume of Fluid VOF ; Lagrangian Particle Tracking LPT ; Large Eddy Simulation LES ; bubble; multiphase; turbulent flows; CFD; hydro-turbine;

   Sammanfattning : Cavitation is a problem in many hydroelectric power plants since it can cause adverse effects on performance and damage to nearby solid surfaces. The concerns of this thesis are the numerical aspects of flow simulations in cavitating hydraulic turbines which contain several difficulties: turbulent and complex flows, steady and moving parts of the geometry, bubble transport and cavitation development. LÄS MER

5. 4. Numerical Study of Dispersed Two-phase Flows

   Författare :Zhilei Wu; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal engineering; Teknik; Technological sciences; Eulerian Lagrangian model.; Eulerian Eulerian model; Lagrangian Particle Tracking; Large Eddy Simulation; Two-phase flow; Particle Image Velocimetry; applied thermodynamics; Termisk teknik; termodynamik;

   Sammanfattning : This thesis considers the numerical study of dispersed two-phase flows.Numerical simulations have been done to investigate the particle trasportation/dispersion effect in turbulent two-phase flows. Both turbulent bubble/water flows and turbulent particle/air flows are studied. LÄS MER

7. 5. Fluid Dynamics in Gas-Liquid Stirred Tank Reactors: Experimental and Theoretical Studies of Bubble Coalescence

   Författare :Rahman Sudiyo; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational Fluid Dynamics; Turbulence; Buoyancy; Bubble Coalescence; Multiphase Flow; High-Speed Video Imaging; Particle Image Velocimetry; Collision Mechanisms;

   Sammanfattning : This work deals with studies of bubble coalescence in turbulent flows of gas-liquid stirred tank reactors. Coalescence plays an important role in determining bubble size distribution, on which flow and mass transfer in such reactors largely depend. LÄS MER