Sökning: "Temperature inhomogeneity"

Visar resultat 11 - 15 av 23 avhandlingar innehållade orden Temperature inhomogeneity.

1. 11. Development of Zonal Models for Analysis of Engine Knock

   Författare :Shahrokh Hajireza; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; homogeneous autoignition; engine knock; Zonal modeling; SI engine; hot-spot autoignition; exothermic centers; wall heat transfer; application of detailed chemical kinetic mechanism of n-heptane and iso-octane; Motors and propulsion systems; Motorer; framdrivningssystem;

   Sammanfattning : Autoignition in SI engines is an abnormal combustion mode and may lead to engine knock which is an undesired phenomenon in SI engines. It may cause damage and it is a source of noise in engines. Knock limits the compression ratio of the engine and a low compression ratio means low fuel conversion efficiency of the engine. LÄS MER

3. 12. Valorization of Kraft Lignin by Fractionation and Chemical Modifications for Different Applications

   Författare :Selda Aminzadeh; Mikael Lindström; Hasan Jameel; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lignin Valorization- LignoBoost Lignin-Clean Flow Black Lignin- Characterization-Chemical modifications-Fractionation-applications; Chemical Engineering; Kemiteknik;

   Sammanfattning : AbstractLignin is one of the most abundant biopolymers. Approximately 70 million tons of technical lignin is generated annually, but only little is used for products other than energy. The complexity of lignin hinders full utilization in high-value products and materials. LÄS MER

4. 13. Varestraint Weldability Testing of Cast Superalloys

   Författare :Sukhdeep Singh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Varestraint; Hot Cracking; Welding; Alloy 718; Cast Superalloys; ATI® 718 PlusTM; HIP;

   Sammanfattning : Precipitation hardened Ni- and Ni-Fe- based superalloys, used in hot structural components for aero engines, are subjected to hot cracking phenomena during manufacturing and specifically in welding. This type of cracking involves metallurgical reactions from the liquid phase in concomitance to weld restraints. LÄS MER

5. 14. An Experimental Study on Melt Fragmentation, Oxidation and Steam Explosion during Fuel Coolant Interactions

   Författare :Louis Manickam; Weimin Ma; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; severe accident; fuel coolant interactions; melt jet breakup; debris properties; steam explosion; oxidation; high-speed visualization; Physics; Fysik;

   Sammanfattning : Nordic type boiling water reactors (BWRs) adopt reactor cavity flooding as a severe accident mitigation strategy (SAMS) to achieve core melt fragmentation and long-term cooling of decay heat generating core debris. The qualification of this SAMS needs to address two main severe accident issues: debris bed coolability and steam explosion. LÄS MER

7. 15. Electron transport properties of graphene and graphene field-effect devices studied experimentally

   Författare :Youngwoo Nam; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; dual-gated graphene field effect devices; thermopower; quantum Hall effect; graphene; Aharonov-Bohm effect; chemical vapour deposition;

   Sammanfattning : This thesis contains experimental studies on electronic transport properties of graphene with the Aharonov-Bohm (AB) effect, thermopower (TEP) measurements, dual-gated graphene field effect devices, and quantum Hall effect (QHE). Firstly, in an effort to enhance the AB effect in graphene, we place superconducting-metal (aluminium) or normal-metal (gold) mirrors on the graphene rings. LÄS MER