Sökning: "surface parameterization"

Visar resultat 11 - 15 av 33 avhandlingar innehållade orden surface parameterization.

  1. 11. Flow Control and Shape Optimization of Intermediate Turbine Ducts for Turbofan Engines

    Författare :Fredrik Wallin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; response surface methodology; intermediate turbine duct; vortex generators; turbine intermediate case; endwall contouring; turbine center frame; body-force model; shape optimization; mid-turbine frame; flow control;

    Sammanfattning : Demands on improved efficiency, reduced emissions and lowered noise levels cause a strive towards high by-pass ratios of commercial turbofan engines. This results in an increased radial offset between the high- and low-pressure turbines. Thus the design of the intermediate turbine duct connecting the two turbines becomes more challenging. LÄS MER

  2. 12. Methods to measure mass transfer kinetics, partition ratios and atmospheric fluxes of organic chemicals in forest systems

    Författare :Damien Johann Bolinius; Annika Jahnke; Matthew MacLeod; Michael McLachlan; Antonio Di Guardo; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrophobic organic chemicals; vegetation; modified Bowen ratio; surface-atmosphere fluxes; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Vegetation plays an important role in the partitioning, transport and fate of hydrophobic organic contaminants (HOCs) in the environment. This thesis aimed at addressing two key knowledge gaps in our understanding of how plants exchange HOCs with the atmosphere: (1) To improve our understanding of the uptake of HOCs into, and transfer through, leaves of different plant species which can significantly influence the transport and fate of HOCs in the environment; and (2) To evaluate an experimental approach to measure fluxes of HOCs in the field. LÄS MER

  3. 13. Studies of stratocumulus-topped boundary layers using a numerical weather prediction model

    Författare :Robert Sigg; Peter Duynkereke; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; meteorologi; Meteorology;

    Sammanfattning : Persistent stratocumulus clouds are commonly observed in many areas on Earth. In general, stratocumulus clouds cool the Earth-atmosphere system due to their influence on the radiation budget. It is therefore essential to describe such clouds accurately in climate and numerical weather prediction models. LÄS MER

  4. 14. Local Effects On Icing Forecasts for Wind Power In Cold Climate

    Författare :Erik Janzon; Anna Rutgersson; Metodija Shapkalijevski; Heiner Körnich; Johan Arnqvist; Alfredo Peña; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorologi; Meteorology;

    Sammanfattning : Understanding the risk of atmospheric icing on wind turbines is crucial for the operation of wind farms in cold climate regions. Processes leading to atmospheric icing in the planetary boundary layer are subject to interactions with the land surface--the details of which are largely unknown in current numerical weather prediction models and must be parameterized. LÄS MER

  5. 15. Level-set methods and geodesic distance functions

    Författare :Ola Nilsson; Ken Museth; Hamish Alan Carr; Linköpings universitet; []
    Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The work in this thesis focuses on efficient implementations of level-set methods and geodesic distance functions. The level-set method is a grid based design that inherits many favorable traits from implicit geometry. LÄS MER