Sökning: "Turbulence-modeling"

Visar resultat 1 - 5 av 20 avhandlingar innehållade ordet Turbulence-modeling.

  1. 1. Time-accurate Turbulence Modeling of Swirling Flow for Hydropower Application

    Författare :Ardalan Javadi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hybrid RANS-LES; Swirling Flow; DES; Vortex Breakdown; Turbulence Modeling; Hydropower; LES;

    Sammanfattning : Hydraulic turbomachines have played a prominent role in the procurement of renewableenergy for more than a century. Embedded in the context of general technological progress,their design for efficiency and reliability has reached an outstanding level of quality. LÄS MER

  3. 2. Turbulence modeling using automated code generation applied to asymmetric diffuser flow

    Författare :Johan Gullman-Strand; KTH; []
    Nyckelord :Fluid mechanics; Turbulence modeling; Explicit algebraic Reynolds stress model; Low-Re K-w; Automated code generation; Wall distance function;

    Sammanfattning : .... LÄS MER

  4. 3. Turbulence modeling of compressible flows with large density variation

    Författare :Igor Grigoriev; Arne Johansson; Stefan Wallin; Geert Brethouwer; Stefan Hickel; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; DRSM; EARSM; active scalar; compressible flow; reacting flow; supercritical flow; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : In this study we highlight the influence of mean dilatation and mean density gradient on the Reynolds stress modeling of compressible, heat-releasing and supercritical turbulent flows.Firstly, the modeling of the rapid pressure-strain correlation has been extended to self-consistently account for the influence of mean dilatation. LÄS MER

  5. 4. Turbulence-resolving Simulations of Swirling Flows

    Författare :Ardalan Javadi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Swirling Flow; URANS; Hydropower; Hybrid URANS-LES; SAS; Flow Control; Turbulence Modeling; Vortex Breakdown; DDES; LES;

    Sammanfattning : A series of numerical investigations is undertaken using a wide range of turbulence mod-els including conventional and non-conventional URANS models, hybrid URANS-LESmethods and LES to capture a large variety of physical mechanisms that produce pres-sure pulsations in the swirling flows. The available knowledge about these pulsations,which are usual in hydropower, are still far from complete. LÄS MER

  7. 5. Numerical Simulation of Some Heat Transfer and Fluid Flow Phenomena for Gas Turbine Blades and a Transonic Turbine Stage

    Författare :Fadil Mumic; Värmeöverföring; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluiddynamik; plasma; Thermal engineering; applied thermodynamics; plasmas; Gaser; fluid dynamics; Gases; transonic; numerical; heat transfer coefficient; shroud surface; squealer blade tip; flat blade tip; leakage flow; Termisk teknik; termodynamik; turbulence modeling;

    Sammanfattning : With the attempts to achieve higher thermal efficiency, turbine blades are exposed to very high temperature gases and may undergo severe thermal stress and fatigue. Thus, in order to develop optimal cooling strategies and reduce the heat transfer it is important to obtain a good understanding of both the complex flow field and the heat transfer characteristics in turbine rotor/stator hot-gas passages. LÄS MER