Sökning: "Fluid surface roughness flow"

Visar resultat 1 - 5 av 39 avhandlingar innehållade orden Fluid surface roughness flow.

1. 1. Global stability analysis of three-dimensional boundary layer flows

   Författare :Mattias Brynjell-Rahkola; Dan Henningson; Philipp Schlatter; Ardeshir Hanifi; Spencer Sherwin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic stability; transition to turbulence; global analysis; boundary layers; roughness; laminar flow control; Stokes Laplace preconditioner; optimal forcing; crossflow vortices; Ginzburg-Landau; Falkner-Skan-Cooke; Blasius; lid-driven cavity;

   Sammanfattning : This thesis considers the stability and transition of incompressible boundary layers. In particular, the Falkner–Skan–Cooke boundary layer subject to a cylindrical surface roughness, and the Blasius boundary layer with applied localized suction are investigated. LÄS MER

3. 2. Flow Over Large-Scale Naturally Rough Surfaces

   Författare :Robin Andersson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : The fluid mechanical field of rough surface flows has been developed ever since the first experiments by Haagen (1854) and Darcy (1857). Although old, the area still holds merit and a surprising amount of information have to this day yet to be fully understood, which surely is a proof of its complexity. LÄS MER

4. 3. Investigations of Flow Patterns in Ventilated Rooms Using Particle Image Velocimetry : Applications in a Scaled Room with Rapidly Varying Inflow and over a Wall-Mounted Radiator

   Författare :Amir Sattari; Ivo Martinac; Mats Sandberg; Dirk Müller; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Particle Image Velocimetry PIV ; experimental study; structured light 3D scanning system; ventilation; varying flow rate; room model; wall-mounted radiator; air; water; flow; Particle Image Velocimetry PIV ; experimentell studie; scanningsystem för strukturerat 3D-ljus; ventilation; varierande tilluftsflöde; rumsmodell; väggmonterad radiator; Engineering Mechanics; Teknisk mekanik; Byggvetenskap; Civil and Architectural Engineering; Energy Technology; Energiteknik;

   Sammanfattning : This thesis introduces and describes a new experimental setup for examining the effects of pulsating inflow to a ventilated enclosure. The study aimed to test the hypothesis that a pulsating inflow has potential to improve ventilation quality by reducing the stagnation zones through enhanced mixing. LÄS MER

5. 4. The effect of scale on the morphology, mechanics and transmissivity of single rock fractures

   Författare :Nader Fardin; KTH; []
   Nyckelord :Anisotropy; Aperture; Asperity degradation; Contact area; Finite Element Method FEM ; Flow analysis; Fractals; Fracture morphology; Heterogeneity; Stress-deformation; Surface roughness; Roughness-Length method; Scale dependency; Stationarity; Transm;

   Sammanfattning : This thesis investigates the effect of scale on themorphology, mechanics and transmissivity of single rockfractures using both laboratory and in-situ experiments, aswell as numerical simulations. Using a laboratory 3D laserscanner, the surface topography of a large silicon-rubberfracture replica of size 1m x 1m, as well as the topography ofboth surfaces of several high-strength concrete fracturereplicas varying in size from 50mmx50mm to 200mm x 200mm, werescanned. LÄS MER

7. 5. Stress, Flow and Particle Transport in Rock Fractures

   Författare :Tomofumi Koyama; Lanru Jing; Marc Boulon; KTH; []
   Nyckelord :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