Search for dissertations about: "Roughness"

Showing result 11 - 15 of 511 swedish dissertations containing the word Roughness.

2. 11. Time-domain modelling of high-frequency wheel/rail interaction

   Author : Astrid Pieringer; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel rail interaction; railway noise; roughness; time domain; frictional instability; discrete irregularities; transient contact; non-Hertzian contact;

   Abstract : The interaction between wheel and rail is the predominant source of noise emission from railway operations in a wide range of conventional speeds. On the one hand, this wheel/rail noise concerns rolling noise and impact noise caused by the vertical interaction excited by roughness and discrete irregularities of the wheel/rail running surfaces, respectively. READ MORE

4. 12. On the influence of surface roughness on rolling contact forces

   Author : Oskar Lundberg; Ines Lopez Arteaga; Leif Kari; Matthias Kröger; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rolling contact; Surface roughness; Contact forces; Contact modelling; Friction; Road; Asphalt; Substrate; Test-rig; Sliding; Stick–slip; Tyre; Rubber; Tread-block; Wheel–rail interaction; Vehicle and Maritime Engineering; Farkostteknik;

   Abstract : Road vehicle tyres, railway wheels and ball bearings all generate rolling contact forces which are transferred within a finite area of contact between the rolling element and the substrate. Either it is visible or not for the human eye, a certain degree of roughness is always present on the contacting surfaces and it influences the generation of both vertical and lateral contactforces. READ MORE

5. 13. Structural Uncertainties of Rock Fractures and their Effect on Flow and Tracer Transport

   Author : Martin Stigsson; Vladimir Cvetkovic; Ki-Bok Min; KTH; []
   Keywords : Fracture; Flow; Transport; Orientation uncertainty; Roughness; Self-affine; Fractal; Shear; Aperture distribution.; Land and Water Resources Engineering; Mark- och vattenteknik;

   Abstract : Att förstå flöde och transport av lösta ämnen genom sprickorna i berggrunden är viktigt för den långsiktiga säkerheten av ett geologiskt slutförvar av farligt avfall. I en diskret spricknätverksmodell byggs flödesvägarna upp av kedjor av flödesvägar genom de enskilda sprickorna i bergmassan. READ MORE

6. 14. Roughest hour – approaches to ship hull fouling management

   Author : Dinis Oliveira; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vessel performance; fouling control coatings; hull grooming; ship resistance; adhesion strength; in-water hull cleaning; biofouling; roughness; turbulent boundary layer;

   Abstract : Submerged surfaces at sea are colonized by a high diversity of sessile (i.e. attached) life forms. As the merchant fleet capacity increases, responding to growth in demand for seaborne transport, so does the hull wetted surface area that is prone to colonization by these sessile organisms, i. READ MORE

7. 15. Efficient Full-Scale CFD for Ship Hydrodynamics

   Author : Michal Orych; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; CFD; Self-propulsion; Ship; Verification; Uncertainty; Full-scale; Validation; Seakeeping; Energy-Saving Device; Roughness; RANS;

   Abstract : An efficient numerical approach for ship hydrodynamics, involving a hybrid free-surface potential flow/RANS method, is explored. The work focuses on estimating the delivered power of ships in calm water and in waves, highlighting the benefits of full-scale simulations, particularly for ships with Energy Saving Devices. READ MORE