Search for dissertations about: "LES"

Showing result 1 - 5 of 189 swedish dissertations containing the word LES.

  1. 1. Methodologies for RANS-LES interfaces in turbulence-resolving simulations

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Sebastian Arvidson; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; zonal RANS-LES; aeronautics; RANS-LES interfaces; Hybrid RANS-LES; grey-area mitigation; log-layer mismatch; embedded LES; LES length scale; LES;

    Abstract : Hybrid Reynolds-Average Navier-Stokes (RANS)-Large-Eddy Simulations (LES) techniques are now seen by the aeronautical industry as the most promising turbulence-resolving approaches for complex high-Reynolds-number turbulent flows with regard to cost and accuracy. However, connecting RANS and LES simulated flows is a challenging task and needs special attention in order to increase simulation robustness and accuracy. READ MORE

  2. 2. Assessment and Some Improvements of Hybrid RANS-LES Methods

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Sebastian Arvidson; [2013]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; hybrid RANS-LES; zonal RANS-LES; embedded LES; PDH-LRN; log-layer mismatch; LES length scale; shock boundary-layer interaction;

    Abstract : Motivated by numerical analysis of a shock/boundary-layer interacting (SBLI) flow in a duct, where some typical existing hybrid RANS-LES methods become awkward to give accurate predictions of the shock-induced corner separation bubble, a new hybrid RANS-LES method, has been proposed. The model is based on a low-Reynolds-number (LRN) $k-\omega$ RANS model, which is one of the few models that are capable of giving reasonable predictions for the SBLI flow in RANS computations. READ MORE

  3. 3. Flow Duct Acoustics An LES Approach

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Emma Alenius; KTH.; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aero-acoustics; duct-acoustics; sound generation; acoustic scattering; acoustic-flow interaction; LES; IC-engines; orifice plate; confined jet;

    Abstract : The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. Simulations are an important tool for enhanced understanding; they give insight into the flow-acoustic interaction in components where it is difficult to perform measurements. READ MORE

  4. 4. Compressible Turbulent Flows LES and Embedded Boundary Methods

    University dissertation from Stockholm : Universitetsservice US AB

    Author : Marco Kupiainen; KTH.; [2009]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; Embedded Boundary methods; Compressible flow; turbulent flow; MATHEMATICS Applied mathematics Numerical analysis; MATEMATIK Tillämpad matematik Numerisk analys; NATURAL SCIENCES Physics Other physics Computational physics; NATURVETENSKAP Fysik Övrig fysik Beräkningsfysik; TECHNOLOGY Engineering mechanics Fluid mechanics; TEKNIKVETENSKAP Teknisk mekanik Strömningsmekanik;

    Abstract : .... READ MORE

  5. 5. Effect of drag reducing plasma actuators using LES

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Romain Futrzynski; KTH.; KTH.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow control; drag reduction; plasma actuator; DMD; LES; optimization; pulsating flow; strömningskontroll; motståndsminskning; plasmaaktuator; DMD; LES; optimering; pulserande strömning; Teknisk mekanik; Engineering Mechanics;

    Abstract : The work performed in this thesis explores new ways of reducing the drag of ground vehicles. Specifically, the effect of plasma actuators are investigated numerically with the intention to delay separation around a half-cylinder, a geometry chosen to represent a simplified A-pillar of a truck. READ MORE