Sökning: "Local Flow Features"

Visar resultat 1 - 5 av 56 avhandlingar innehållade orden Local Flow Features.

  1. 1. Experimental Investigation of the Influence of Local Flow Features on the Aerodynamic Damping of an Oscillating Blade Row

    Författare :Antonio Sanz Luengo; Torsten Fransson; Damian Vogt; Guillermo Paniagua; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbomachinery; Aeroelasticity; Flutter; Experimental Aerodynamics; CFD; Local Flow Features; Influence Coefficient; Linearity Assumption; Aerospace Engineering; Flyg- och rymdteknik;

    Sammanfattning : The general trend of efficiency increase, weight and noise reduction has derived in the design of more slender, loaded, and 3D shaped blades. This has a significant impact on the stability of fan, and low pressure turbine blades, which are more prone to aeroelastic phenomena such as flutter. LÄS MER

  2. 2. Local symmetry features in image processing

    Författare :Josef Bigün; Olivier Fangeras; Linköpings universitet; []

    Sammanfattning : The extraction of features is necessary for all aspects of image processing and analysis such as classification, segmentation, enhancement and coding. In the course of developing models to describe images, a need arises for description of more complex structures than lines. LÄS MER

  3. 3. Turbulence modeling of compressible flows with large density variation

    Författare :Igor Grigoriev; Arne Johansson; Stefan Wallin; Geert Brethouwer; Stefan Hickel; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; DRSM; EARSM; active scalar; compressible flow; reacting flow; supercritical flow; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : In this study we highlight the influence of mean dilatation and mean density gradient on the Reynolds stress modeling of compressible, heat-releasing and supercritical turbulent flows.Firstly, the modeling of the rapid pressure-strain correlation has been extended to self-consistently account for the influence of mean dilatation. LÄS MER

  4. 4. Stress, Flow and Particle Transport in Rock Fractures

    Författare :Tomofumi Koyama; Lanru Jing; Marc Boulon; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical simulation; laboratory experiments; rock fracture; coupled stress-flow-tracer test; shear displacement; fluid flow; particle transport; finite element method FEM ; particle tracking method; Navier-Stokes equation; Reynolds equation; streamline velocity dispersion.; Geoengineering; Geoteknik;

    Sammanfattning : The fluid flow and tracer transport in a single rock fracture during shear processes has been an important issue in rock mechanics and is investigated in this thesis using Finite Element Method (FEM) and streamline particle tracking method, considering evolutions of aperture and transmissivity with shear displacement histories under different normal stresses, based on laboratory tests. The distributions of fracture aperture and its evolution during shear were calculated from the initial aperture fields, based on the laser-scanned surface roughness features of replicas of rock fracture specimens, and shear dilations measured during the coupled shear-flow-tracer tests in laboratory performed using a newly developed testing apparatus in Nagasaki University, Nagasaki, Japan. LÄS MER

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

    Författare :Peng Shia-Hui; Chalmers University of Technology; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER