Sökning: "flow propagation velocity"

Visar resultat 31 - 35 av 35 avhandlingar innehållade orden flow propagation velocity.

  1. 31. Laser welding and cladding : the effects of defects on fatigue behaviour

    Författare :Md. Minhaj Alam; Stewart Williams; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Manufacturing Systems Engineering; Produktionsutveckling;

    Sammanfattning : The thesis focuses on weld defects in laser processed materials (for laser welding, laser hybrid arc welding and laser cladding) and their effect on the fatigue life of components. Component properties were studied with particular emphasis on the macro and micro surface geometry, weld defects and clad defects. LÄS MER

  2. 32. Turbulent burning, flame acceleration, explosion triggering

    Författare :V'yacheslav Akkerman; Vitaly Bychkov; Geoffrey Searby; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Turbulent combustion; flame acceleration; detonation explosion triggering; direct numerical simulations; Physics; Fysik;

    Sammanfattning : The present thesis considers several important problems of combustion theory, which are closely related to each other: turbulent burning, flame interaction with walls in different geometries, flame acceleration and detonation triggering. The theory of turbulent burning is developed within the renormalization approach. LÄS MER

  3. 33. Quantitative controls on the routing of supraglacial meltwater to the bed of glaciers and ice sheets

    Författare :Caroline Clason; Douglas Mair; Peter Nienow; University of Aberdeen Geography and Environment; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Glaciers Greenland Moulins Supraglacial Crevasses Modelling; geografi med naturgeografisk inriktning; Geography; Physical Geography; Hydrology; hydrologi;

    Sammanfattning : The influence of seasonal influx of supraglacial meltwater on basal water pressures and consequent changes in ice surface velocity has been a focus of research spanning over three decades, particularly focussing on alpine glaciers. Now, with increased recognition for a need to better include glacial hydrology within models of ice dynamics and ice sheet evolution, the ability to predict where and when meltwater is delivered to the subglacial system is paramount, both for understanding the dynamics of alpine glaciers, and of large Arctic ice masses. LÄS MER

  4. 34. Characterization of energy gases by ultrasound : theory and experiments

    Författare :Pär-Erik Martinsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : The long-term goal with the research presented in this thesis has been to develop an ultrasonic sensor capable of measuring the energy content of energy gases such as natural- and biogas. The energy content can be calculated if the concentration of each constituent of a gas mixture is known. LÄS MER

  5. 35. Laser Diagnostic Techniques with Ultra-High Repetition Rate for Studies in Combustion Environments

    Författare :Jimmy Olofsson; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High-Speed; High Repetition Rate; LIF; PLIF; 3D Visualisation; Engine; Teknik; Technological sciences; Fysik; Physics; Combustion; Laserteknik; Laser technology; Laser-Induced Fluorescence; Laser Diagnostics;

    Sammanfattning : When conducting laser based diagnostics in combustion environments it is often desirable to obtain temporally resolved information. This can be due to several factors such as combustion taking place in a turbulent flow field, flame propagation from a spark plug in an initially quiescent combustible mixture, or rapid, multi-point fuel consumption in a homogeneous charge as a result of compression ignition in an engine cycle. LÄS MER