Search for dissertations about: "two-equation model"

Showing result 1 - 5 of 22 swedish dissertations containing the words two-equation model.

2. 1. Numerical Simulation of Turbulent Flows for Turbine Blade Heat Transfer Applications

   Author : Jonas Larsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; k-.omega.; k-.epsilon.; explicit Runge-Kutta; finite volume; turbine; numerical method; non-linear; Navier-Stokes; supersonic; two-equation; external heat transfer; stagnation flow; two-dimensional; transition; low-Reynolds; turbulence model; impulse blade;

   Abstract : Turbine blade heat transfer is an important engineering problem characterized by complex flow fields and high turbulence levels. This thesis is focused on using a full Navier-Stokes solver with two-equation eddy-viscosity models to predict external heat-transfer in single-stage, linear, two-dimensional uncooled turbine cascades. READ MORE

4. 2. On Turbulence Modelling for Bilge Vortices: A Test of Eight Models for Three Cases

   Author : Urban Svennberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wake; turbulence modelling; nonlinear eddy-viscosity model; bilge vortices; ship flow; jet; Navier-Stokes equation; two-equation model; Reynolds stress model; vortex;

   Abstract : This work is a test, in three steps, of turbulence models for the calculation of the flow field around ships. Eight models ranging from k-e and k-w models to a Reynolds-stress model (RSM) are tested. READ MORE

5. 3. Modelling of Turbulent Flow and Heat Transfer for Building Ventilation

   Author : Peng Shia-Hui; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; large eddy simulation; turbulent buoyant convection; ventilation performance assessment; purging flow rate; SGS modelling; ventilation flow; stochastic Markov chain model; turbulence modelling; LRN k-w model; two-equation models; building ventilation; transfer probability; transition regime; modified SGS buoyancy model; energy backscatter;

   Abstract : This thesis contributes to studies on the assessment of building ventilation performance and the development of turbulence models accounting for Low-Reynolds-number (LRN) effects and buoyant convection with heat transfer. Assessments of building ventilation performance are discussed with respect to indoor air distribution and passive contaminant dispersion. READ MORE

6. 4. Turbulence Modelling of Flows Related to Wall-Cooling Applications

   Author : Stefan Jansson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; low-Reynolds number models; second-order-moment closures; turbulent heat transfer; two-equation models; film-cooling; near-wall models; turbulence modelling;

   Abstract : Engineering flows are generally characterised by complex strain field and turbulence structure arising from a combination of shear, curvature, separation and recirculation etc. Under such flow conditions, transport by turbulent velocity fluctuations can make a significant contribution to the transport of momentum, heat and mass. READ MORE

7. 5. The age of transported scalars in fluid mechanics

   Author : Federico Ghirelli; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; grate furnace; velocity correlation; fluid age; scalar age; turbulence model; residence time; energy spectrum; turbulence age;

   Abstract : Computational fluid dynamics (CFD) is applied to the reacting flow in the freeboard of a 30MW biofuel fired grate furnace and results are validated by comparison with data from an extensive measurement campaign. The influence of the fuel bed model on the results of the freeboard model is investigated. READ MORE