Podrobnosti záznamu

Název
    Hydrodynamic experiments on dacryoconarid shell telescoping
Autor
    Hladil, Jindřich
    Kulaviak, Lukáš
    Lisý, Pavel
    Růžička, Marek
    Šimčík, Miroslav
Jazyk
    anglicky
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Lethaia
Svazek/č.
    Roč. 47, č. 3
Strany
    s. 376-396
Rok
    2014
Poznámky
    Projekt: GAP210/10/2351, GA ČR3cav_un_auth*0263318
    Rozsah: 21 s. : P
Předmětová kategorie
    dacryoconarid shells
    experimental fluid mechanics
    narrow cones
    Palaeozoic
    telescoping
Klíčové slovo
    Dacryoconarid
    Experiments
    Hydrodynamic
    Shell
    Telescoping
Abstrakt (anglicky)
   It is not uncommon that small conical dacryoconarid shells are found inserted one into another. Although this phenomenon has been studied for decades, and interparticle collisions in turbulent flows have largely considered to be responsible, no satisfactory explanation has been provided. We performed experiments under laboratory conditions using narrow aluminium cones as replicas of these shells. Two different flow regimes were tested to mimic the probable hydrodynamic conditions in the ocean. First, large-scale rhythmic back and forth coherent motion of water over the seabed was reproduced in an oscillating sloshing tank (sloshing mode). Second, small-scale irregular stirring motion in turbulent bulk was imitated in cylindrical containers placed into a shaker (mixing mode). With sloshing, a high production of irreversibly telescoped cones was present in clear water and at driving frequencies comparable to the upper limits known for sea waves.
   With shaking, both coalescence and break-up of the cones were observed, as the quasi-random hydrodynamic forces generated by vigorous liquid motion were roughly comparable with the mechanical forces holding the cones together. However, the stability of the clusters of telescoped cones in the shaker could be enhanced with the addition of fine solid particles (suspended silt). In addition, a simple mathematical model was suggested for the flow interaction with a submerged conical particle in the case of the sloshing mode, providing an interesting insight into the evolution of strong deceleration zones
Přispěvatel
    AV ČR Brno, Geologický ústav
Kód přispěvatele
    AV ČR, GLÚ
Zdrojový formát
    U
Datum importu
    23. 10. 2014