Search for dissertations about: "Flow stress"

Showing result 1 - 5 of 449 swedish dissertations containing the words Flow stress.

2. 1. Wings, turbulent boundary layers and flow separation

   Author : Fermin Mallor; Philipp Schlatter; Ricardo Vinuesa; Ramis Örlü; Manuel García Villalba; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wings; turbulent boundary layers; adverse pressure gradients; flow separation; numerical simulations; wind-tunnel experiments; flow control.; Vingar; turbulenta gränsskikt; negativa tryckgradienter; avlösning; numeriska simuleringar; vindtunnel-experiment; flow control; Aerospace Engineering; Flyg- och rymdteknik; Teknisk mekanik; Engineering Mechanics;

   Abstract : The present doctoral thesis investigates the turbulent flow developing around wing sections, focusing on the impact of adverse-pressure-gradient (APG) conditions on turbulent boundary layers (TBLs) and the physics of flow separation. Both experimental and numerical methods are employed to generate high-fidelity data sets and provide an in-depth analysis of the flow. READ MORE

4. 2. Fibre flow mechanisms

   Author : Roger Bergström; Ulf Björkman; Bo Norman; Mark Martinez; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fibre flow; floc; shear; compression; fibre network; stress chain; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Abstract : The flow behaviour, and primarily the floc-floc interaction, of pulp paper suspensions have been studied visually. Analogy models based on these observations have been developed as well as the identification of important parameters of floc break-up in low shear rate flow fields. READ MORE

5. 3. Interaction of flows with slender structures and liquid-infused surfaces

   Author : Johan Sundin; Shervin Bagheri; Daniel Chung; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow-structure interactions; flow control; turbulent boundary layers; soft sensors; drag reduction; capillary waves; surfactants; Marangoni stress; mixing enhancement; Engineering Mechanics; Teknisk mekanik;

   Abstract : Surface textures and protrusions can be used to control or gain information about a flow. We investigate the solid-flow interaction of filamentous structures and liquid-infused surfaces (LIS). Both filamentous structures and LIS are used by organisms and can be exploited in technical applications. READ MORE

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

   Author : Tomofumi Koyama; Lanru Jing; Marc Boulon; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

7. 5. Numerical investigation of the flow and instabilities at part-load and speed-no-load in an axial turbine

   Author : Jelle Kranenbarg; Michel Cervantes; Lisa Prahl Wittberg; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speed-no-load; vortical flow structures; flow instabilities; rotating stall; mitigation; independent guide vanes; axial turbine; swirling flow; off design operation; URANS; parametric study; blade clearance; head losses; diffusor; GEKO model; flow separation; hydraulic turbine; Strömningslära; Fluid Mechanics;

   Abstract : Global renewable energy requirements rapidly increase with the transition to a fossil-free society. As a result, intermittent energy resources, such as wind- and solar power, have become increasingly popular. However, their energy production varies over time, both in the short- and long term. READ MORE