Sökning: "vortex formation"

Visar resultat 21 - 25 av 41 avhandlingar innehållade orden vortex formation.

  1. 21. Unsteady Numerical Simulations and Reduced-Order Modelling of Flows around Vehicles

    Författare :Jan Östh; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduced-Order Modelling; Numerical Simulations; Large Eddy Simulation; Vehicle Aerodynamics;

    Sammanfattning : In this thesis several simulations have been carried out aimed at improving the knowledge of vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Five flows around different simplified vehicle models have been considered in five appended publications. LÄS MER

  3. 22. Analysis of stratospheric ozone depletion in the Arctic using a data assimilation technique

    Författare :Kazutoshi Sagi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; data assimilation; ozone loss; limb sounding; remote sensing; stratosphere;

    Sammanfattning : Serious ozone depletion has been measured every Antarctic spring since the early 80’s. This ozone depletion is considered to be a result of photo chemical reactions and cat- alytic cycles resulting from anthropogenic halogen containing gases. LÄS MER

  4. 23. A study of mold flux entrapment and gas entrainment in an ingot casting process

    Författare :Jun Yin; Mikael Ersson; Pär Jönsson; Yogeshwar Sahai; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mold flux entrapments; CFD; Gas entrainment; Ingot casting process; Uphill teeming process; Side teeming process; Numerical simulation; Non-metallic inclusions; Metallurgical process science; Metallurgisk processvetenskap; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : The focus of this work is to study the gas entrainment and mold flux entrapments during the ingot filling process based on physical and numerical modelling.The formation of the free surface was investigated in the uphill teeming method, which illustrates a dynamic change at a quasi-steady state. LÄS MER

  5. 24. Studies of the flow pattern in short term hot water storages

    Författare :Pascal Veber; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy Engineering; Energiteknik;

    Sammanfattning : This thesis relates to the study of thermally stratified hot water storages used in district heating systems and is an extension of the doctoral theses of Jan Dahl and Roger Hermansson. The thermal performance of a stratified water storage is reduced by different phenomena such as heat transfer to the surroundings and mixing between hot and cold water during the charging of the tank. LÄS MER

  7. 25. Decadal analysis of stratospheric ozone depletion using data assimilation and Odin/SMR measurements

    Författare :Kazutoshi Sagi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ozone loss; remote sensing; stratosphere; limb sounding; data assimilation;

    Sammanfattning : Serious ozone depletion has been measured every Antarctic spring since the early 80’s. This ozone depletion is considered to be a result of photo-chemical reactions and catalytic cycles resulting from anthropogenic halogen containing gases. facilitated by the formation of Polar Stratospheric Clouds (PSCs). LÄS MER