Sökning: "Tall objects"

Hittade 4 avhandlingar innehållade orden Tall objects.

  1. 1. Experimental Observations and Theoretical Modeling of Lightning Interaction with Tall Objects

    Författare :Helin Zhou; Rajeev Thottappillil; Gerhard Diendorfer; Daohong Wang; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tall objects; Upward lightning initiation; Charge density distribution; Upward positive lightning; Upward bipolar lightning;

    Sammanfattning : This thesis investigates various discharge processes associated with upward lightning initiated from tall objects, both experimentally and theoretically, trying to bridge the knowledge-gap in understanding the mechanisms of the phenomena.Upward lightning initiation has attracted a great deal of interest during recent years due to the proliferation of tall communication towers and wind turbines. LÄS MER

  3. 2. Urban Evolution

    Författare :Claes Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In nature, objects formed from a dynamics on one level often form yet new objects and new dynamics on a new level. This process generates a hierarchical organization of nature that is particularly tall for objects that are of biological or human origin. LÄS MER

  4. 3. On the Attachment of Lightning Flashes to Grounded Structures

    Författare :Marley Becerra; Vernon Cooray; Rajeev Thottappillil; Mats Boman; Ivo Gallimberti; Uppsala universitet; []
    Nyckelord :Engineering physics; Lightning; Lightning attachment; Positive leader discharges; Lightning protection; Thunderstorms; Numerical modeling; Teknisk fysik;

    Sammanfattning : This thesis deals with the physical modeling of the initiation and propagation of upward positive leader discharges from grounded structures during lightning strikes. It includes the analysis of upward leaders initiated under the influence of the electric field produced by a dominant negative cloud charge and due to the combined action of a negative thundercloud and a descending downward stepped negative leader. LÄS MER

  5. 4. Shells and filament in flows

    Författare :Vipin Agrawal; Dhrubaditya Mitra; Supriya Krishnamurthy; Gerhard Gompper; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chaos; Elastic filaments; Shells; Exosomes; Stokes flow; Theoretical Physics; teoretisk fysik;

    Sammanfattning : The motivation to study elastic structures such as filaments and shells stemmed from its application in the construction of tall buildings, bridges etc. Interest in this field has rekindled in the past decades due to growing interest in understanding biological materials and because of possible applications in nanoscience and medicine. LÄS MER