Search for dissertations about: "RANS"

Showing result 1 - 5 of 89 swedish dissertations containing the word RANS.

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

    University dissertation from Gothenburg : Chalmers tekniska högskola

    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. Development of a Free Surface Capability in a RANS Solver with Coupled Equations and Overset Grids

    University dissertation from Gothenburg : Chalmers tekniska högskola

    Author : Michal Orych; [2013]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; free-surface; overset; RANS;

    Abstract : This thesis is a result of investigations carried out during the implementation of a free surface capturing method in a RANS solver. The work consists of two distinct parts which complement each other, and the purpose is to improve the free surface interface sharpness and to reduce numerical diffusion of the gravity waves. READ MORE

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

    University dissertation from Gothenburg : Chalmers tekniska högskola

    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

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

    University dissertation from Gothenburg : Chalmers tekniska högskola

    Author : Walter Gyllenram; [2008]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; vortex; draft tube; hydro turbine; filter; RANS; LES; swirling flow;

    Abstract : Swirling flows are common in technical applications, e.g. turbines, pumps, fans, compressors and combustors. READ MORE

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

    University dissertation from Gothenburg : Chalmers tekniska högskola

    Author : Abdallah Abou-Taouk; [2011]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAS-SST; Global reaction mechanism; CFD; LES; RANS; Combustion; PSR; Chemistry;

    Abstract : 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. READ MORE