Sökning: "secondary flow"

Visar resultat 1 - 5 av 268 avhandlingar innehållade orden secondary flow.

  1. 1. Numerical Studies of Flow and AssociatedLosses in the Exhaust Port of a Diesel Engine

    Författare :Yue Wang; Laszlo Fuchs; Mihai Mihaescu; Angelo Onorati; KTH; []
    Nyckelord :Internal Combustion Engine; Exhaust flow; Exhaust Valve; Exhaust Port; Large Eddy Simulation; Valve and Piston Motion; Total Pressure Losses; Energy Losses; Discharge coefficient; Flow Losses; Flow structures; Air Flow Bench; Engine-like Conditions; SRA - Energy; SRA - Energi;

    Sammanfattning : In the last decades, the focus of internal combustion engine development has moved towards more efficient and less pollutant engines. In a Diesel engine, approximately 30-40% of the energy provided by combustion is lost through the exhaust gases. The exhaust gases are hot and therefore rich of energy. LÄS MER

  3. 2. Aerodynamic Investigations of a High Pressure Turbine Vane with Leading Edge Contouring at Endwall in a Transonic Annular Sector Cascade

    Författare :Ranjan Saha; Torsten Fransson; Markus Jöcker; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high pressure turbine; secondary flow; leading edge contouring; endwall; experimental investigations; losses; flow field; hub cooling flow; högtrycksturbinen sekundärströmning; framkantsmodifiering; ändvägg; experimentell undersökning; förluster; strömningsfält; filmkylning av inre platform;

    Sammanfattning : Efficiency improvement is an important aspect to reduce the use of fossil-based fuel in order to achieve a sustainable future. Gas turbines are mainly fossil-fuel based turbomachines, and, therefore, efficiency improvement is still the subject of many on-going research activities in the gas turbine community. LÄS MER

  4. 3. Optimal Control of Boundary Layer Transition

    Författare :Markus Högberg; KTH; []
    Nyckelord :laminar-turbulent transition; transition control; turbulence control; flow control; boundary layer flow; channel flow; optimal control; adjoint equations; Riccati equations; Orr--Sommerfeld--Squire equations; secondary instability; transient gro;

    Sammanfattning : .... LÄS MER

  5. 4. Experimental study of turbulent flows through pipe bends

    Författare :Athanasia Kalpakli; P. Henrik Alfredsson; Ramis Örlü; Christoph Brücker; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent flow; swirl; pulsation; pipe bend; hot-wire anemometry; cold-wire anemometry; laser Doppler velocimetry; stereoscopic particle image velocimetry.;

    Sammanfattning : This thesis deals with turbulent flows in 90 degree curved pipes of circular cross-section. The flow cases investigated experimentally are turbulent flow with and without an additional motion, swirling or pulsating, superposed on the primary flow. LÄS MER

  7. 5. Numerical computations of the unsteady flow in a radial turbine

    Författare :Fredrik Hellström; Laszlo Fuchs; Jonas Bredberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pulsatile flow; radial turbines; pipe flow; effects of inlet conditions; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Non-pulsatile and pulsatile flow in bent pipes and radial turbine has been assessed with numerical simulations. The flow field in a single bent pipe has been computed with different turbulence modelling approaches. LÄS MER