Sökning: "SST k − ω"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden SST k − ω.

  1. 1. FLOW FIELD IN A HIGH HEAD FRANCIS TURBINE DRAFT TUBE DURING TRANSIENT OPERATIONS

    Författare :Rahul Goyal; Michel J. Cervantes; Bhupendra K. Gandhi; Gabriel Ciocan; Lisa Prahl; Ramis Orlu; Gunilla Andree; Andrea Toffolo; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Francis turbine; Steady state; Transient; Particle Image Velocimetry; Vortex Rope; Strömningslära; Fluid Mechanics;

    Sammanfattning : Hydroelectricity plays an important role to balance the stability of grid network.  In order to improve the stability of presently high loaded grids, hydropower plants are being operated over a wide range of operations and experiencing frequent start-stop, load rejection, and load acceptance. LÄS MER

  3. 2. Numerical and experimental study of confluent jets supply device with variable airflow

    Författare :Harald Andersson; Bahram Moshfegh; Mathias Cehlin; Fredrik Karlsson; Högskolan i Gävle; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Confluent jets; Air distribution system; Air supply device; Ventilation performance; Indoor air quality; Thermal comfort; Experimental study; Laser Doppler Anemometry LDA ; Computational fluid dynamics CFD ; Shear stress transport SST k – ω ; confluent jets; luftdistributionssystem; tilluftsdon; ventilationsprestanda; inomhusluftkvalitet; termisk komfort; experimentell studie; Laser-Doppler-anemometri LDA ; Computational fluid dynamics CFD ; turbulens model SST k – ω ; Hållbar stadsutveckling; Sustainable Urban Development;

    Sammanfattning : In recent years, application of confluent jets for design of ventilation supply devices has been studied. Similarly, numerus studies have been made on the potential and application of variable air volume (VAV) in order to reduce the energy demand of ventilation systems. LÄS MER

  4. 3. Turbine Outlet Guide Vane Flows

    Författare :Johan Hjärne; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spalart-Allmaras model; k-ω SST model; linear cascade; secondary flows; turbine exhaust casing; RSM; k-ε realizable model; turbine rear frame; engine mount bump; tail bearing housing; Outlet guide vane;

    Sammanfattning : New design goals on modern jet engines often leads to more highly loaded turbines with fewer stages in order to save weight and cost. This gives higher swirl angles into the outlet guide vane (OGV), implying a more difficult aerodynamic design. LÄS MER

  5. 4. Computational Modelling for Cavitation and Tip Vortex Flows

    Författare :Abolfazl Asnaghi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cavitation; SST k − ω; OpenFOAM; Propeller; LES; Numerical simulation; Cur- vature correction; Elliptical foil; Inception; Twisted Delft foil;

    Sammanfattning : Cavitation often brings negative effects, such as performance degradation, noise, vibration, and material damage, to marine propulsion systems, but for optimum performance, cavitation is almost inevitable. Therefore, it is necessary to better understand cavitation in order to maximize the performance without encounter- ing severe problems. LÄS MER

  7. 5. Numerical prediction of propeller induced hull pressure pulses and noise

    Författare :Muye Ge; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; RANS; Transition; IDDES; Cavitation; Pressure pulses; Sheet cavitation inception; Ship noise; k − ω SST; FWH acoustic analogy; Hydroacoustics;

    Sammanfattning : An operating marine propeller is one of the major sources inducing hull pressure pulses, onboard noise and vibration as well as underwater radiated noise. There are rising concerns of environmental impacts and comfort and welfare of passengers and crews due to these negative effects. LÄS MER