Sökning: "LES"

Visar resultat 1 - 5 av 328 avhandlingar innehållade ordet LES.

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

    Författare :Sebastian Arvidson; Chalmers University of Technology; []
    Nyckelord :zonal RANS-LES; aeronautics; RANS-LES interfaces; Hybrid RANS-LES; grey-area mitigation; log-layer mismatch; embedded LES; LES length scale; LES;

    Sammanfattning : 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. LÄS MER

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

    Författare :Sebastian Arvidson; Chalmers University of Technology; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 3. Flow Duct Acoustics : An LES Approach

    Författare :Emma Alenius; Mats Åbom; Laszlo Fuchs; Oliver Paschereit; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aero-acoustics; duct-acoustics; sound generation; acoustic scattering; acoustic-flow interaction; LES; IC-engines; orifice plate; confined jet;

    Sammanfattning : 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. LÄS MER

  4. 4. Les sacres : en socio-kulturell analys av tio versioner av ett Våroffer

    Författare :Katarina Lion; Stockholms universitet; []
    Nyckelord :HUMANITIES; HUMANIORA; HUMANIORA; HUMANITIES; reconstruction; original; hierarchies; dance history; colonialism; primitive; the other; rite.; teatervetenskap; Theatre Studies;

    Sammanfattning : The purpose of the dissertation is to bring to light and focus upon, through a number of disparate investigations, the socio-cultural ideology and practices expressed in some of the dance events which constitute an echo of the cry implied by the most canonized ballet of the 1900s, Le Sacre du Printemps choreographed in 1913 by Vaslav Nijinsky. The study commences with a discussion, which aims to define key concepts such as "reconstruction" and "original". LÄS MER

  5. 5. Compressible Turbulent Flows : LES and Embedded Boundary Methods

    Författare :Marco Kupiainen; Bjorn Engquist; William Henshaw; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURVETENSKAP; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; LES; Embedded Boundary methods; Compressible flow; turbulent flow; Numerical analysis; Numerisk analys; Computational physics; Beräkningsfysik; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : .... LÄS MER