Sökning: "Air Entrainment"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden Air Entrainment.

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

    Författare :Penghua Teng; James Yang; Anders Wörman; Anton Schleiss; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 2. Modelling air―water flows in bottom outlets of dams

    Författare :Ting Liu; James Yang; Anders Wörman; Michael Pfister; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Air pocket; Air entrainment; Bottom outlet; Critical velocity; Critical submergence; CFD; Experiment; Vortex; PIV; Two-phase air―water flow; Mark- och vattenteknik; Land and Water Resources Engineering; Civil and Architectural Engineering; Byggvetenskap;

    Sammanfattning : If air is entrained in a bottom outlet of a dam in an uncontrolled way, the resulting air pockets may cause problems such as blowback, blowout and loss of discharge capacity. In order to provide guidance for bottom outlet design and operation, this study examines how governing parameters affect air entrainment, air-pocket transport and de-aeration and the surrounding flow structure in pipe flows. LÄS MER

  4. 3. Spray Processes in Optical Diesel Engines - Air-Entrainement and Emissions

    Författare :Clement Chartier; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diesel; Combustion; Soot; UHC; Injections; Lift-off length; air-entrainement;

    Sammanfattning : Internal combustion engines have been an important technological field for more than a century. It has had an important impact on society through improved transportation and industrial applications. LÄS MER

  5. 4. Experimental Investigation of ultra-high fuel injection pressure spray for GDI engines

    Författare :Akichika Yamaguchi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spray; Spray imaging; Air entrainment; High Pressure; PIV; Spray tip penetration; GDI engine; PDI; drolet size;

    Sammanfattning : Gasoline Direct Injection Engines (GDI) for passenger cars currently use fuel injection systems operating at pressures of up to 350 bar. Injection pressures have increased over time, and there is evidence that particulate emissions could be reduced by raising them further, up to 500 bar. LÄS MER

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

    Författare :Shicheng Li; Anders Ansell; James Yang; Robert Boes; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER