Search for dissertations about: "breakdown strength"

Showing result 16 - 20 of 55 swedish dissertations containing the words breakdown strength.

  2. 16. Wind-turbine wakes - Effects of yaw, shear and turbine interaction

    Author : Elektra Kleusberg; Dan Henningson; Philipp Schlatter; Stefan Ivanell; Johan Meyers; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind-turbine wakes; yaw; tip-vortex breakdown; shear; computational fluid dynamics; actuator-line method; spectral-element method; Vindturbinsvakar; girning; turbulent nedbrott hos spetsvirvlar; skjuvning; vakinteraktion; beräkningsströmningsdynamik; actuator line-metod; spektralelementmetod; Engineering Mechanics; Teknisk mekanik;

    Abstract : The actuator-line method is used together with the incompressible Navier–Stokes equations to investigate the flow development behind wind turbines. Initial investigations focus on providing a thorough validation of the implementation in the spectral-element flow solver Nek5000 against existing numerical and experimental datasets. READ MORE

  4. 17. Selection of oxygen carriers for chemical-looping combustion using methane as a fuel

    Author : Marcus Johansson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Carbon Dioxide Capture; Nickel oxide; CO2 Separation; Oxygen Carrier; Iron oxide; Manganese oxide.; Chemical-Looping Combustion;

    Abstract : In order to meet new demands on clean energy producing technologies, chemical-looping combustion could play an important role. With this technique, CO2 from the flue gases can be separated and collected without excessive energy and efficiency penalty. This is because nitrogen from the combustion air is never mixed with the fuel. READ MORE

  5. 18. Features and Origin of Electromagnetic Fields Generated by Lightning Flashes

    Author : Mohd Muzafar Ismail; Vernon Cooray; Farhad Rachidi; Uppsala universitet; []
    Keywords : negative cloud-to-ground lightning flashes; HF and VHF radiation; chaotic pulse trains; lightning initiation; zero-crossing time; electromagnetic fields; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

    Abstract : Negative cloud-to-ground (CG) lightning flashes transport negative charge from cloud to ground. Negative ground flashes typically involve various processes identified as preliminary breakdown, stepped leader, return stroke, dart leader, dart-stepped leader, subsequent return stroke, and cloud activity between strokes, such as regular pulse trains and chaotic pulse trains. READ MORE

  6. 19. Computed Tomography and Fingerprint Traceability in the Wood Industry

    Author : Erik Johansson; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Träteknik; Wood Technology;

    Abstract : The purpose of the work described in this thesis was to develop techniques based on non-invasive measurements of logs and sawn timber that would increase the profitability of the wood industry in general and sawmills in particular. The work has two main focus areas: computed tomography (CT) scanning of logs and traceability of wood products. READ MORE

  7. 20. Efficient utilization of sawlogs using scanning techniques and computer modelling

    Author : Anders Berglund; Arto Usenius; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Träteknik; Wood Technology;

    Abstract : The main question asked of the work described in this thesis was howthe sawing of logs into sawn timber can be performed more efficientlywith respect to the choice of raw material, volume and value yield in thesawing and in the grading of the sawn timber produced.The development of industrial computed tomography scanning providesinformation about the external and internal properties of a sawlogat production speed. READ MORE