MULTI-POINT LAGRANGIAN VELOCITY ESTIMATES
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10389793" target="_blank" >RIV/00216208:11320/18:10389793 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.14311/TPFM.2018.038" target="_blank" >https://doi.org/10.14311/TPFM.2018.038</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.14311/TPFM.2018.038" target="_blank" >10.14311/TPFM.2018.038</a>
Alternative languages
Result language
angličtina
Original language name
MULTI-POINT LAGRANGIAN VELOCITY ESTIMATES
Original language description
Micron-sized particles of solid deuterium are suspended in superfluid He-4 (He II) and their time-dependent positions are captured by using the particle tracking velocimetry technique. As the computation of the particle velocities from the obtained positions can be noisy, mainly due to experimental uncertainties, we compare here four different numerical approaches to estimate the velocities. We choose, as a test case, the flow of He II occurring between two grids oscillating in phase, which, in the range of investigated parameters, display classical like features, very similar to those found in turbulent flows of viscous fluids. We focus on algorithms that consider multiple particle positions for the estimation of a single velocity. Although the velocities computed by the chosen procedures are relatively similar, we find that the statistical distributions of the corresponding velocity increments, i.e., coarse-grained accelerations, depend on the choice of the algorithm and its parameters in a more pronounced way than in the case of velocities. It follows therefore that the numerical approach employed to estimate Lagrangian velocity increments should be chosen carefully on the basis of the physical problem being investigated.
Czech name
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Czech description
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Classification
Type
D - Article in proceedings
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)
Result continuities
Project
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Continuities
S - Specificky vyzkum na vysokych skolach
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Article name in the collection
TOPICAL PROBLEMS OF FLUID MECHANICS 2018
ISBN
978-80-87012-65-9
ISSN
2336-5781
e-ISSN
neuvedeno
Number of pages
10
Pages from-to
281-290
Publisher name
ACAD SCI CZECH REPUBLIC, INST THERMOMECHANICS
Place of publication
PRAGUE 8
Event location
Prague
Event date
Feb 21, 2018
Type of event by nationality
WRD - Celosvětová akce
UT code for WoS article
000457661300038