Sökning: "Mechanical Engineering Aerospace Engineering"

Visar resultat 1 - 5 av 284 avhandlingar innehållade orden Mechanical Engineering Aerospace Engineering.

1. 1. 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

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

   Författare :Oskar Thulin; 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; 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;

   Sammanfattning : 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. LÄS MER

4. 3. Modeling Diesel spray combustion using a Detailed Chemistry Approach

   Författare :Jonas Edman; 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;

   Sammanfattning : The rapid development of computer hardware during the past decade has contributed substantially to advances in almost all branches of science. Computer modeling is being applied to increasingly small physical scales and increasingly large domains, facilitating the generation of advanced phenomenological models and models based on first principles. LÄS MER

5. 4. 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

7. 5. Large-eddy simulation on the effects of fuel injection pressure on gasoline spray characteristics

   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; High pressure fuel-injection; GDI engine; LES; Spray characteristics;

   Sammanfattning : Increasing the injection pressure in gasoline direct injection engines has a substantial potential to reduce emissions while maintaining high efficiency in spark ignition engines. Present gasoline injectors operate at pressures of 20 to 30 MPa. LÄS MER