Sökning: "RANS models"

Visar resultat 1 - 5 av 63 avhandlingar innehållade orden RANS models.

  1. 1. Analysis of the Performance of Different V2F Turbulence Models in a Stator Vane Passage Flow

    Författare :Andreas Sveningsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat transfer; RANS; realizability; V2F; stator flow;

    Sammanfattning : When designing the cooling system of modern gas turbines it is important to be able to predict the heat transfer from the hot gas to the walls surrounding the gas path. One flow feature making this rather complicated is the presence of secondary, three-dimensional flow structures, often referred to as horse shoe vortices, which greatly enhance the rate of heat transfer to the endwall, especially in the leading edge region. 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. Computational fluid dynamics for dispersion calculation in urban surroundings

    Författare :Jan Burman; Anna Rutgersson; Sven-Erik Gryning; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CFD; RANS; LES; Toxicological effects; Synthetic boundary conditions; Stable boundary layer.; Meteorologi; Meteorology;

    Sammanfattning : Increased knowledge on dispersion processes in urban environment will enhance the ability in the society to handle events where releases of toxic substances can occur. Also, the ability to increase preparedness at locations where such events potentially can emerge. LÄS MER

  5. 4. 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

  7. 5. Mooring dynamics for wave energy applications

    Författare :Johannes Palm; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hp adaptivity; Wave energy; Coupled simulations; CFD; Discontinuous Galerkin methods; OpenFOAM; Mooring dynamics; Snap loads; RANS;

    Sammanfattning : This work aims to increase the modelling accuracy of two important problems for the wave energy industry. One concerns the mooring dynamics in the presence of snap loads (shock waves in cable tension). The other is related to nonlinear effects in the resonance region of moored wave energy converters (WECs). LÄS MER