Search for dissertations about: "turbulence flow modeling"

Showing result 1 - 5 of 100 swedish dissertations containing the words turbulence flow modeling.

  2. 1. Turbulence modeling of compressible flows with large density variation

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

    Abstract : 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. READ MORE

  4. 2. Modeling of magnetohydrodynamic turbulence

    Author : Ola Widlund; KTH; []
    Keywords : turbulence model; magnetohydrodynamic; mhd; magnetohydrodynamic turbulence; computational fluid dynamics; continuous casting;

    Abstract : Conventional one-point turbulence closures have beenextended with an additional transported scalar for modeling ofmagnetohydrodynamic (MHD) turbulence. The new scalar, α ,captures the length scale anisotropy and tendency towardstwo-dimensionality, which is characteristic feature of MHDturbulence, and allows accurate modeling of the Jouledissipation of turbulence. READ MORE

  5. 3. Explicit algebraic subgrid-scale stress and passive scalar flux modeling in large eddy simulation

    Author : Amin Rasam; Arne V. Johansson; Shia-Hui Peng; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; Large eddy simulation; explicit algebraic subgrid-scale model; passive scalar; stochastic modeling; backscatter; Fluid mechanics; Strömningsmekanik;

    Abstract : The present thesis deals with a number of challenges in the field of large eddy simulation (LES). These include the performance of subgrid-scale (SGS) models at fairly high Reynolds numbers and coarse resolutions, passive scalar and stochastic modeling in LES. READ MORE

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

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

    Abstract : 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. READ MORE

  7. 5. Turbulence-resolving Simulations of Swirling Flows

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

    Abstract : 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. READ MORE