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Visar resultat 21 - 25 av 102 avhandlingar som matchar ovanstående sökkriterier.

1. 21. Numerical Optimization of a propeller in a given wake and behind a ship

   Författare :Kaijia Han; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; propeller geometry; pressure fluctuation; correction; full scale; efficiency; RANS; cavitation; grid density; verification; delivered power; optimization; Hamburg test case; iteration number;

   Sammanfattning : The work presented in this thesis includes two stages in a research project at the Rolls-Royce University Technology Center (UTC) at Chalmers Technology University. The objective of the project is to develop an optimization technique for ship/propeller interaction. LÄS MER

3. 22. Polyethylene – metal oxide particle nanocomposites for future HVDC cable insulation : From interface tailoring to designed performance

   Författare :Dongming Liu; Ulf Gedde; Mikael Hedenqvist; Richard Olsson; Linda Schadler; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; electrical insulation; core-shell nanoparticles; surface modification; silane chemistry; nanocomposites; polyethylene; adsorption; long-term stability; interface; particle dispersion; cavitation; conductivity; HVDC; elektrisk isolation; ytmodifiering; silankemi; nanokompositer; polyeten; adsorption; långtidsstabilitet; ytskikt; partikeldispergering; kavitation; ledningsförmåga; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Low-density polyethylene (LDPE) nanocomposites containing metal oxide nanoparticles are considered as promising candidates for insulating materials in future high-voltage direct-current (HVDC) cables. The significant improvement in dielectric properties compared with unfilled polymer is attributed to the large and active interface between the nanoparticles and the polymer. LÄS MER

4. 23. Large eddy simulation of cavitating and non-cavitating flow

   Författare :Tobias Huuva; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high Reynolds number; Cavitation; turbulence; RANS; hydrodynamics; numerical simulation; modelling; DES; LES;

   Sammanfattning : Most marine configurations are subject to a number of complex and important hydrodynamic phenomena affecting the overall performance of the vessel, both regarding resistance and propulsive efficiency. In this thesis, the possibility of numerically simulating some of these phenomena is investigated. LÄS MER

5. 24. Numerical Modelling of Diesel Spray Injection, Turbulence Interaction and Combustion

   Författare :Fabian Kärrholm Peng; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Atomization; Spray; Flame; Cavitation; Ignition Delay; Lift-off; Combustion; Computational Fluid Dynamics; Numerical Scheme; TVD; Diesel; Turbulence Model;

   Sammanfattning : This thesis covers two main topics. The first is numerical modelling ofcavitating diesel injector flows, focusing on describing suchflows using asingle-phase cavitation model based on a barotropic equation of statetogetherwith a homogenous equilibrium assumption. LÄS MER

7. 25. Homogenization of some new mathematical models in lubrication theory

   Författare :Afonso Fernando Tsandzana; Peter Wall; Lars- Erik Persson; John Fabricius; Anders Holmbom; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lubrication theory; homogenization theory; Reynolds equation; cavitation; surfaces roughness; Stokes equation; Matematik; Mathematics;

   Sammanfattning : We consider mathematical modeling of thin film flow between two rough surfaces which are in relative motion. For example such flows take place in different kinds of bearings and gears when a lubricant is used to reduce friction and wear between the surfaces. LÄS MER