Sökning: "particle flow method"

Visar resultat 1 - 5 av 201 avhandlingar innehållade orden particle flow method.

1. 1. 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

3. 2. Particle-fluid interactions under heterogeneous reactions

   Författare :Thamali Rajika Jayawickrama; Kentaro Umeki; Nils Erland L. Haugen; Matthaus Babler; Muhammad Aqib Chishty; Henrik Ström; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stefan flow; drag coefficient; Nusselt number; Sherwood number; particle-fluid flow; reacting flow; Energy Engineering; Energiteknik;

   Sammanfattning : Particle-fluid flows are involved in many natural processes and industrial applications; some examples are drying, solid fuel combustion, gasification, and catalytic cracking. It is vital to understand the phenomena involved in particle-fluid flows in depth for design, predictions and process improvements. LÄS MER

4. 3. Numerical modelling of fluid flow and particle transport in rough rock fracture during shear

   Författare :Tomofumi Koyama; Lahru Jing; Auli Niemi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single rock fracture; coupled stress-flow test; shear displacement; fluid flow; particle; Geoengineering; Geoteknik;

   Sammanfattning : The effects of different shearing processes and sample sizes on the fluid flow anisotropy and its impact on particle transport process in rough rock fractures are significant factors that need to be considered in the performance and safety assessments of underground nuclear waste repositories. The subjects, however, have not been adequately investigated previously in either laboratory experiments or numerical modeling. LÄS MER

5. 4. Fluid dynamics and flow structures of wood fibres suspended in gas flows

   Författare :Olof Melander; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; two-fluid model; fibres; flocculation; multiphase flow; flow regimes; particle transport; fibre suspensions; Particle Image Velocimetry; Computational Fluid Dynamics; lift force; concentration measurement;

   Sammanfattning : The flow of wood fibres suspended in gas plays a major role in the MDF (Medium Density Fibreboard) production process. Development of machinery in this industry has traditionally been based on experience. Only recently has the use of numerical methods such as CFD (Computational Fluid Dynamics) become an important part of the development process. LÄS MER

7. 5. Accuracy, efficiency and robustness for rigid particle simulations in Stokes flow

   Författare :Anna Broms; Anna-Karin Tornberg; Mattias Sandberg; Eric Keaveny; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stokes flow; rigid particles; accuracy; fundamental solutions; method of images; multiblob; contact avoiding; complementarity problem; barrier method; elliptic PDE; grid optimisation; pair-correction; boundary integral equations; Stokesflöde; noggrannhet; stela partiklar; fundamentallösningar; randintegralekvation; reflektionspunkter; multiblob; kontaktundvikande algoritmer; komplementaritetsproblem; barriärmetod; elliptisk PDE; gridoptimering; parkorrektion; Numerical Analysis; Numerisk analys;

   Sammanfattning : The thesis concerns simulation techniques for systems of nano- to micro-scaled rigid particles immersed in a viscous fluid, ubiquitous in nature and industry. With negligible fluid inertia, the set of PDEs known as the Stokes equations can be used to model the hydrodynamics. LÄS MER