Sökning: "Other Mechanical Engineering"

Visar resultat 6 - 10 av 7009 avhandlingar innehållade orden Other Mechanical Engineering.

  1. 6. Differential railway track settlement in a transition zone – Field measurements and numerical simulations

    Författare :Kourosh Nasrollahi; Chalmers tekniska högskola; []
    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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fibre Bragg grating sensors; dynamic vehicle–track interaction; heavy haul traffic; non-linear track model; 3MB slab track; Transition zone; empirical settlement model; condition monitoring;

    Sammanfattning : In a transition zone between two different railway track forms, there is a discontinuity in track structure leading to a gradient in track stiffness. Examples include transitions between different superstructures, e.g., slab track to ballasted track, and/or between different substructures, e. LÄS MER

  3. 7. Component and system design of a mild hybrid 48 V powertrain for a light vehicle

    Författare :Stefan Skoog; Chalmers tekniska högskola; []
    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; Extra low voltage; Hybrid Electric Vehicle; 48 V; Li-ion battery; Calorimetric measurement; Oil cooling; Efficiency; Multi-phase; MOSFET; Power Electronics; Permanent Magnet Synchronous Machine; PWM; Inverter; Power density;

    Sammanfattning : This thesis presents contributions in three areas relevant for the development of 48 V mild hybrid electric powertrains for cars. The first part comprises methodologies and extensive testing of lithium-ion battery cells in order to establish the electric and thermal performance using equivalent circuit models. LÄS MER

  4. 8. Large-Eddy Simulation of Gasoline Fuel Spray Injection at Ultra-High Injection Pressures

    Författare :Sandip Wadekar; Chalmers tekniska högskola; []
    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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; High pressure fuel injection; spray-wall interaction; spray-turbulence interaction; GDI engine; Spray modeling;

    Sammanfattning : Gasoline direct injection is a state-of-the-art technique that reduces hydrocarbon and particulate emissions. However, further improvement is needed to meet current as well as future emission regulations. LÄS MER

  5. 9. Techno-Economic Perspectives on Biofuel Futures – Modelling Transport Sector Strategies in an Energy System Context

    Författare :Martin Börjesson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; biogas; oil dependence; model; MARKAL; transport; CO2; optimisation; biofuel;

    Sammanfattning : The high oil dependence and the continuous growth of energy use in the transport sector have in recent years triggered interest in transport biofuels as a measure to mitigate climate change andimprove energy security. This work aims to examine techno-economic interactions linked totransport biofuel strategies in national and regional energy systems and their implications for thecost-effective realisation of energy policy objectives. LÄS MER

  7. 10. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges

    Författare :Anton Kersten; Chalmers tekniska högskola; []
    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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic reconfiguration; Energy storage; Energy efficiency; Drive cycle efficiency; Power MOSFET; vehicles; H-bridge; Multilevel systems; Electromagnetic compatibility; Modular battery systems; Battery system performance; Modular multilevel converters; Conduction losses; Electric vehicles; Batteries; Dual battery pack; Cascaded converters; DC-AC power converters; BMS; Common mode noise; Battery modeling; vehicle electrification;

    Sammanfattning : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. LÄS MER