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Showing result 1 - 5 of 6 swedish dissertations matching the above criteria.

2. 1. Energy Consumption and Running Time for Trains : modelling of running resistance and driver behaviour based on full scale testing

   Author : Piotr Lukaszewicz; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy consumption; Running time; running resistance; driver behaviour; freight; train; energy coasting method; aerodynamic drag; driver model; degree of coasting; slippage; wind; Energy saving; braking ratio; powering ratio; full scale testing; Vehicle engineering; Farkostteknik;

   Abstract : The accuracy in determined energy consumption and runningtime of trains, by means of computer simulation, is dependent upon the various models used. This thesis aims at developing validated models of running resistance, train and of a generaldriver, all based on full scale testing. READ MORE

4. 2. On the Analysis of Energy Efficient Aircraft Engines

   Author : Oskar Thulin; Chalmers tekniska högskola; []
   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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Performance modelling; Aero engine; Turbofan; Aircraft engine; Installed propulsion; Ultra high bypass ratio; Exergy analysis; Engine weight estimate; Variable area fan nozzle; Multiple pivoting flaps; Translating cowls;

   Abstract : Aero engine performance analysis is highly multidimensional using various measures of component performance such as turbomachinery and mechanical efficiencies, and pressure loss coefficients. Using conventional performance analysis, relying on only the laws of thermodynamics, it is possible to understand how the performance parameters affect the component performance, but it is difficult to directly compare the magnitude of various loss sources. READ MORE

5. 3. Molecular Gas in Seyfert Galaxies

   Author : S.J. Curran; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; star-burst-nuclei-dynamics; galaxies; star-burst-nuclei-kinematics; interstellar medium molecules; Seyfert;

   Abstract : In this report we present the results of a single dish study of the molecular gas properties in Seyfert galaxies. From the observations of the closest lying example, the Circinus galaxy, we find that about half of the molecular gas is distributed in a circumnuclear ring orbiting the central super-massive black hole, believed to be powering this type 2 Seyfert. READ MORE

6. 4. Modeling and Control of VSC-HVDC Links Connected to Weak AC Systems

   Author : Lidong Zhang; Hans-Peter Nee; Alan Wood; KTH; []
   Keywords : Control; modeling; multivariable feedback control; HVDC; power systems; stability; subsynchronous torsional interaction; voltage-source converter; weak ac systems;

   Abstract : For high-voltage direct-current (HVDC) transmission, the strength of the ac system is important for normal operation. An ac system can be considered as weak either because its impedance is high or its inertia is low. READ MORE

7. 5. Numerical Studies of Methanol PPC Engines and Diesel Sprays

   Author : Mateusz Pucilowski; Strömningsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Methanol; Partially Premixed Combustion PPC ; spray-wall interaction; piston geometry; multiple injections; ICE; ignition front; diffusion flame; combustion mode; RANS; LES; PPC; Diesel spray;

   Abstract : The global environment suffers from utilizing fossil fuels to powering internal combustion engines (ICE), due to the massive amounts of released CO2. Besides the global impact, the local environments experience high concentrations of harmful pollutants such as NOx, CO, soot and particulate matter (PM). READ MORE