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Hydrodynamic experiments on dacryoconarid shell telescoping

SYSNO ASEP	0429385
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Hydrodynamic experiments on dacryoconarid shell telescoping
Author(s)	Hladil, Jindřich (GLU-S)_{RID, SAI} Šimčík, Miroslav (UCHP-M)_{RID, SAI, ORCID} Růžička, Marek (UCHP-M)_{RID, ORCID, SAI} Kulaviak, Lukáš (UCHP-M)_{RID, ORCID, SAI} Lisý, Pavel (GLU-S)_{RID, SAI}
Source Title	Lethaia. - : Wiley - ISSN 0024-1164 Roč. 47, č. 3 (2014), s. 376-396
Number of pages	21 s.
Publication form	Print - P
Language	eng - English
Country	NO - Norway
Keywords	dacryoconarid shells ; experimental fluid mechanics ; narrow cones ; Palaeozoic ; telescoping
Subject RIV	DB - Geology ; Mineralogy
Subject RIV - cooperation	Institute of Chemical Process Fundamentals - Industrial Chemistry, Chemical Engineering
R&D Projects	GAP210/10/2351 GA ČR - Czech Science Foundation (CSF)
Institutional support	GLU-S - RVO:67985831 ; UCHP-M - RVO:67985858
UT WOS	000337691500008
EID SCOPUS	84902072775
DOI	10.1111/let.12065
Annotation	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
Workplace	Institute of Geology
Contact	Jana Popelková, popelkova@gli.cas.cz, Sabina Janíčková, Tel.: 233 087 272
Year of Publishing	2015

Number of the records: 1