Sökning: "turbulence modeling"

Visar resultat 31 - 35 av 125 avhandlingar innehållade orden turbulence modeling.

1. 31. Turbulence Descriptors in Arterial Flows : Patient-Specific Computational Hemodynamics

   Författare :Magnus Andersson; Matts Karlsson; Jonas Lantz; Tino Ebbers; Kristian Valen-Sendstad; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : At this very moment, there are literally millions of people who suffer from various types of cardiovascular diseases (CVDs), many of whom will experience reduced quality of life or premature lift expectancy. The detailed underlying pathogenic processes behind many of these disorders are not well understood, but were abnormal dynamics of the blood flow (hemodynamics) are believed to play an important role, especially atypical flow-mediated frictional forces on the intraluminal wall (i. LÄS MER

3. 32. Stochastic Reactor Models for Engine Simulations

   Författare :Martin Tunér; Förbränningsmotorer; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SRM; Stochastic Reactor Model; Engine Simulation; Chemical kinetics; HCCI; Direct injection; Combustion; NVO; Modeling; PDF;

   Sammanfattning : The aim of the thesis work is the further development of practical engine simulation tools based on Stochastic Reactor Models, SRMs. Novel and efficient implementations were made of a variety of SRMs adapted to different engine types. The models in question are the HCCI-SRM, the TwoZone SI-SRM and the DI-SRM. LÄS MER

4. 33. Prediction of forced convection heat transfer to Lead-Bismuth-Eutectic

   Författare :Roman Thiele; Henryk Anglart; Martin Rohde; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lead-bismuth-eutectic; Forced convective heat transfer; Turbulence-modeling; GEN-IV reactors;

   Sammanfattning : The goal of this work is to investigate the capabilities of two different commercial codes, OpenFOAM and ANSYS CFX, to predict forced convection heat transfer in low Prandtl number fluids and investigate the sensitivity of these predictions to the type of code and to several input parameters.The goal of the work is accomplished by predicting forced convection heat transfer in two different experimental setups with the codes OpenFOAM and ANSYS CFX using three different turbulence models and varying the input parameters in an extensive sensitivity analysis. LÄS MER

5. 34. Analytical vortex solutions to Navier-Stokes equation

   Författare :Henrik Tryggeson; Mats Lyberg; Maarten Brons; Växjö universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; conical vortex; Navier-Stokes equation; analytical solution; 2-D vortices; turbulence; vortex ring; stretched vortex; coherent structures; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : Fluid dynamics considers the physics of liquids and gases. This is a branch of classical physics and is totally based on Newton's laws of motion. Nevertheless, the equation of fluid motion, Navier-Stokes equation, becomes very complicated to solve even for very simple configurations. LÄS MER

7. 35. Dynamics of Fluid Particles in Turbulent Flows; CFD simulations, Model Development and Phenomenological Studies

   Författare :Ronnie Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Particle Image Velocimetry; Coalescence; Breakup; Multiphase Flow; Computational Fluid Dynamics; Planar laser induced fluorescence; Population Balance Modelling; Turbulence; High speed imaging technique; Mass Transfer; Refractive index matching;

   Sammanfattning : The thesis investigates the dynamics of fluid particles in turbulent flows, which plays an important role in the chemical, pharmaceutical, food and petroleum industries. Phenomenological studies, new mathematical models for the breakup phenomena, and development of a simulation method for chemical reactors constitute the main parts of this thesis. LÄS MER