Search for dissertations about: "Air-water two-phase flow"

Showing result 1 - 5 of 6 swedish dissertations containing the words Air-water two-phase flow.

2. 1. CFD MODELLING AND EXPERIMENTS ON AERATOR FLOW IN CHUTE SPILLWAYS

   Author : Penghua Teng; James Yang; Anders Wörman; Anton Schleiss; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spillway Aerator; Cavitation; Air Entrainment; Two-phase Flow; VOF; Mixture Model; Two-Fluid Model; Air Cavity; Cavity Air Pressure; Air Concentration; Shadowgraphic Image Method SIM ; High-speed Particle Image Velocimetry HSPIV ; Bubble Tracking Method BTM ; luftningsramp; kavitation; luftinträngning; tvåfasflöde; VOF; Mixture Model; Two-Fluid Model; luftkavitet; kavitetslufttryck; luftkoncentration; skuggrafisk bildmetod; hastighetsmätning med höghastighetspartikelfotografering; bubbelspårningsmetod; Byggvetenskap; Civil and Architectural Engineering;

   Abstract : A chute spillway is a typical component of large dams for discharging floods. Because of the high water head, the flow velocity in the chute is often in excess of 20 m/s. Consequently, the structure is usually prone to cavitation damages. Flow aeration is evidenced to efficiently eliminate or to mitigate the damages. READ MORE

4. 2. Air-pocket transport in conjunction with bottom-outlet conduits for dams

   Author : Ting Liu; Anders Wörman; James Yang; Staffan Lundström; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Air-water two-phase flow; critical velocity; diameter effect; roughness; VOF model; bottom outlet; experiment;

   Abstract : Undesired air entrainment in bottom outlet conduits of dams may cause pressure transients, leading to conduit vibrations, blowback, discharge pulsation and even cavitation, and jeopardize the operational safety. Due to design limitations or construction costs, it is impossible to create an air free environment in a pressurized pipe. READ MORE

5. 3. CFD and data-driven modeling for safe spillway discharge

   Author : Shicheng Li; Anders Ansell; James Yang; Robert Boes; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Discharge safety; hydraulic design; spillway; discharge capacity; aerator; two-phase flow; air entrainment; energy dissipation; CFD; data-driven modeling; Betongbyggnad; Concrete Structures;

   Abstract : A spillway is a crucial dam structure that regulates water levels and prevents the dam from overtopping. The majority of the dams in the world were constructed before the 1980s. Compared to the current design flood standards, many spillways are undersized, e.g. READ MORE

6. 4. Experimental Study and Modelling of Spacer Grid Influence on Flow in Nuclear Fuel Assemblies

   Author : Diana Caraghiaur Garrido; Henryk Anglart; Dominique Bestion; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; spacer grid influence; annular flow; deposition; Lagrangian Particle Tracking;

   Abstract : The work is focused on experimental study and modelling of spacer grid influence on single- and two-phase flow. In the experimental study a mock-up of a realistic fuel bundle with five spacer grids of thin plate spring construction was investigated. A special pressure measuring technique was used to measure pressure distribution inside the spacer. READ MORE

7. 5. Mechanistic Modeling of Annular Flows at Near-Dryout Conditions

   Author : Wenyuan Fan; Henryk Anglart; Martin Rohde; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kärnenergiteknik; Nuclear Engineering;

   Abstract : This work aims at advancing the modeling methodology for near-dryout annular flows using two different computational fluid dynamics (CFD) approaches. One is termed as the transported film approach, where the film flow is separately modeled by a simplified liquid film model and then coupled with the gas core simulation using various closures. READ MORE