Sökning: "Hybrid RANS LES"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden Hybrid RANS LES.

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

    Författare :Sebastian Arvidson; Chalmers tekniska högskola; []
    Nyckelord :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;

    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

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

    Författare :Sebastian Arvidson; Chalmers tekniska högskola; []
    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

  4. 3. Aerodynamic and Aeroacoustic Analysis of a Multi-Element Airfoil using Hybrid RANS/LES Modeling Approaches

    Författare :Bastian Nebenführ; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ffowcs-Williams and Hawkings; HYB0; noise; hybrid RANS LES; multi-element airfoil; CAA; Kirchhoff; Curle; high-lift;

    Sammanfattning : Global hybrid RANS/LES simulations were used for computing the turbulent flow around a three-element airfoil. Based on the results of the flow computations, a comprehensive analysis of the flow properties was performed. LÄS MER

  5. 4. Analytical and Numerical Studies of Internal Swirling Flows

    Författare :Walter Gyllenram; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; vortex; draft tube; hydro turbine; filter; RANS; LES; swirling flow;

    Sammanfattning : Swirling flows are common in technical applications, e.g. turbines, pumps, fans, compressors and combustors. LÄS MER

  7. 5. CFD Modeling of Combustion in Flexi-Fuel Burners at Gas Turbine Conditions

    Författare :Abdallah Abou-Taouk; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAS-SST; Global reaction mechanism; CFD; LES; RANS; Combustion; PSR; Chemistry;

    Sammanfattning : The main source of energy in the nearest future will come from fossil fuels. Increasing demands on environmentally friendly energy conversion implies that pollutants, such as CO and NOx, need to be reduced. LÄS MER