Experimental investigation of swirl number influence on spiral vortex structure dynamics
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F21%3APU141174" target="_blank" >RIV/00216305:26210/21:PU141174 - isvavai.cz</a>
Alternative codes found
RIV/61388998:_____/21:00545835
Result on the web
<a href="https://iopscience.iop.org/article/10.1088/1755-1315/774/1/012085" target="_blank" >https://iopscience.iop.org/article/10.1088/1755-1315/774/1/012085</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1088/1755-1315/774/1/012085" target="_blank" >10.1088/1755-1315/774/1/012085</a>
Alternative languages
Result language
angličtina
Original language name
Experimental investigation of swirl number influence on spiral vortex structure dynamics
Original language description
The hydraulic turbines are recently forced to operate far away from the optimal conditions in order to balance fluctuations in electricity generation. In case of Francis, pump and propeller turbines, using only single control component of guide vanes, it means that in regions where the high residual swirl enters the draft tube, the flow is decelerated and convenient conditions for the vortex rope development are created. Such flow conditions are considered to be the triggering mechanism for occurrence of different forms of vortex structures in the Francis turbine draft tube, e.g. spiral or straight vortex rope at part load or full load respectively. Independently on the vortex rope shape the unsteady pressure fields develop producing periodic stress on turbine components and possibly resulting in noise, blade cracks, runner lift, power swing, etc. To study and mimic such flow conditions, a simplified device of vortex generator apparatus is employed. Thanks to its design, the vortex generator enables to change the ratio between fluxes of axial momentum and tangential moment of momentum of generated swirl. Then, the behavior of vortex structure changes in a similar way as the flow rate variation in the draft tube of Francis turbine. For above mentioned reasons the unsteady cavitating spiral vortex is experimentally studied using both high speed video record and particle image velocimetry (PIV). The main focus is on change of vortex dynamics regarding to the swirl number variation. The proper orthogonal decomposition (POD) together with the classical fast Fourier transformation (FFT) are employed to extract dominant modes and frequencies from experimental data.
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
20301 - Mechanical engineering
Result continuities
Project
<a href="/en/project/EF16_026%2F0008392" target="_blank" >EF16_026/0008392: Computer Simulations for Effective Low-Emission Energy Engineering</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Article name in the collection
IOP Conference Series-Earth and Environmental Science
ISBN
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ISSN
1755-1307
e-ISSN
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Number of pages
10
Pages from-to
012085-012085
Publisher name
IOP Publishing
Place of publication
neuveden
Event location
Lausanne
Event date
Mar 21, 2021
Type of event by nationality
WRD - Celosvětová akce
UT code for WoS article
000712043400085