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Visar resultat 1 - 5 av 449 avhandlingar som matchar ovanstående sökkriterier.
1. Wings, turbulent boundary layers and flow separation
Sammanfattning : 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. LÄS MER
2. Fibre flow mechanisms
Sammanfattning : 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. LÄS MER
3. Interaction of flows with slender structures and liquid-infused surfaces
Sammanfattning : 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. LÄS MER
4. Stress, Flow and Particle Transport in Rock Fractures
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. Numerical investigation of the flow and instabilities at part-load and speed-no-load in an axial turbine
Sammanfattning : 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. LÄS MER