Search for dissertations about: "cavitating flows"

Showing result 1 - 5 of 12 swedish dissertations containing the words cavitating flows.

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

   Author : Ebrahim Ghahramani; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Approaching Large Eddy Simulation of Cavitating Flows for Marine Applications

   Author : Niklas Wikström; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VOF; OpenFOAM; CFD; LES; Navier-Stokes; incompressible free surface flow; Cavitation;

   Abstract : Cavitation is a major concern in naval craft design as well as in the shipping industry. Although the nature of cavitation is not fully understood, propellerdesigns are presently improved by experimental analysis of the phenomena. READ MORE

5. 3. Influence of Acoustic Interaction between Cavities That Generate Cavitation Noise

   Author : Jan Hallander; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical simulation; collapse of vapour cavities; experimental studies; pressure pulses; cavitation noise; hydrodynamics; cavitation; bubbles; cavitating flows;

   Abstract : The thesis concerns high frequency cavitation noise generated by marine propellers, for example. The collapse of a cavity is forced by the surrounding pressure which comprises the pressure in the undisturbed flow, the pressure disturbance associated with the local non-cavitating flow and, finally, the pressure disturbance from the presence and motion of neighbouring cavities. READ MORE

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

   Author : Daniel Lörstad; Institutionen för energivetenskaper; []
   Keywords : 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;

   Abstract : 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. READ MORE

7. 5. Assessment of cavitation erosion risk based on single-fluid simulation of cavitating flows

   Author : Mohammad Hossein Arabnejad Khanouki; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : Cavitation erosion is material loss due to the repetitive collapse of cavities near the surface. This phenomenon is one of the limiting factors in the design of high-performance marine propulsors as it restricts their reliability and increases their operational cost. READ MORE