Search for dissertations about: "flow instabilities"

Showing result 1 - 5 of 83 swedish dissertations containing the words flow instabilities.

  2. 1. Numerical investigation of the flow and instabilities at part-load and speed-no-load in an axial turbine

    Author : Jelle Kranenbarg; Michel Cervantes; Lisa Prahl Wittberg; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speed-no-load; vortical flow structures; flow instabilities; rotating stall; mitigation; independent guide vanes; axial turbine; swirling flow; off design operation; URANS; parametric study; blade clearance; head losses; diffusor; GEKO model; flow separation; hydraulic turbine; Strömningslära; Fluid Mechanics;

    Abstract : Global renewable energy requirements rapidly increase with the transition to a fossil-free society. As a result, intermittent energy resources, such as wind- and solar power, have become increasingly popular. However, their energy production varies over time, both in the short- and long term. READ MORE

  4. 2. Flow instabilities in centrifugal compressors at low mass flow rate

    Author : Elias Sundström; Mihai Mihaescu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal compressor; flow instabilities; rotational flows; rotating stall; surge; compressible Large Eddy Simulation; Engineering Mechanics; Teknisk mekanik;

    Abstract : A centrifugal compressor is a mechanical machine with purpose to convert kineticenergy from a rotating impeller wheel into the fluid medium by compressingit. One application involves supplying boost air pressure to downsized internalcombustion engines (ICE). READ MORE

  5. 3. Centrifugal compressor flow instabilities at low mass flow rate

    Author : Elias Sundström; Mihai Mihaescu; Håkan Nilsson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal Compressor; Large Eddy Simulation; Internal Com- bustion Engine; Aeroacoustics; Modal Flow Decomposition;

    Abstract : Turbochargers play an important role in increasing the energetic efficiency andreducing emissions of modern power-train systems based on downsized recipro-cating internal combustion engines (ICE). The centrifugal compressor in tur-bochargers is limited at off-design operating conditions by the inception of flowinstabilities causing rotating stall and surge. READ MORE

  6. 4. Unstable flow of molten polymers

    Author : Johan Becker; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; talc; melt strength; polythylene; fillers; polypropylene; extruder; melt flow instabilities; oscillations; film blowing; composites; frequency analysis; extrudate surface; capillary extursion; polyolefine;

    Abstract : .... READ MORE

  7. 5. Experimental and Numerical Investigations of Flames Stabilized by Swirl Flow and Bluff-body:Flame Structures and Flame Instabilities

    Author : Yiheng Tong; Kraftverksteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flame structures; Flame instabilities; Blowout limits; Flashback; Swirl Flow; Bluff-body; Chemiluminescence; PIV;

    Abstract : Combustion and its control are essential to our existence on this planet since we knew it. Nowadays, the largest share of the world’s electricity and most of our transportation systems are powered by combustion. In addition, industrial processes also rely heavily upon combustion. READ MORE