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Visar resultat 1 - 5 av 118 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Experimental and Numerical Multi-port Eduction for Duct Acoustics

   Författare :Stefan Sack; Abom Mats; Phillip Joseph; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; aeroacoustics; flowacoustics; multi-ports; orifice; silencer; experiment; numeric; IDDES; LNSE; optimization; test rig; Monte Carlo; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : Sound generation and propagation in circular ducts for frequencies beyond the cut-on frequencies of several higher order acoustic modes is investigated. To achieve this, experimental and numerical set-ups are designed and used to research aeroacoustic interactions between in-duct components and to conceive noise mitigation strategies. LÄS MER

3. 2. On the influence of surface roughness on rolling contact forces

   Författare :Oskar Lundberg; Ines Lopez Arteaga; Leif Kari; Matthias Kröger; KTH; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. Combustion Valve Wear : A Tribological Study of Combustion Valve Sealing Interfaces

   Författare :Peter Forsberg; Staffan Jacobson; Rob Dwyer-Joyce; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Combustion valves; wear; tribofilm; test rig; combustion residue; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : The exhaust valve system of combustion engines experiences a very complex contact situation of frequent impact involving micro sliding, high and varying temperatures, complex exhaust gas chemistry and possible particulates, etc. In addition, the tribological situation in the exhaust valve system is expected to become even worse due to strict future emission regulations, which will require enhanced combustion and cleaner fuels. LÄS MER

5. 4. Protective Tribofilms on Combustion Engine Valves

   Författare :Robin Elo; Staffan Jacobson; Mikael Åstrand; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Internal combustion engine; valve; sealing surface; tribofilm; oil residue; test rig; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : Inside the complex machinery of modern heavy-duty engines, the sealing surfaces of the valve and valve seat insert have to endure. Right next to the combustion, temperatures are high and high pressure deforms the components, causing a small relative motion in the interface. LÄS MER

7. 5. High Temperature Corrosion in Fluidised Bed Environment

   Författare :Anna Nafari; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFB; coatings; Ni and iron based alloys; HCl; SO2; loop seal; High temperature corrosion; erosion corrosion test rig; surface characterization and temperature gradient;

   Sammanfattning : Successful material selection for power plants is the result of understanding the environment in each boiler. The boiler environment is affected by fuel chemistry, co-firing, process control and deposits as well as boiler type, design, size and load. LÄS MER