Registration Number
0224U001748,
(0120U101269)
, R & D reports
Title
Wave fields generated by interacting coherent vortex structures
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Визначення критерiю, що дозволяє моделювати великомасштабнi вихровi рухи плям еквiвалентною системою точкових вихорiв та вирiшення питання щодо можливості описувати розподiленi вихори точковими при побудовi звукового джерела.
Head
Krasnopolska Tatiana S., д.ф.-м.н.
Registration Date
28-01-2024
Organization
The Institute of Hydromechanics of the National Academy of Sciences of Ukraine
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Identification of qualitative and quantitative relationships between dynamic and acoustic characteristics of coherent vortex interacting structures;
establishing relationships between large-scale vortex motions and the internal dynamics of Kirchhoff vortices, on the one hand, and the characteristics of sound fields generated in the vortex interaction process, on the other; definition of an acoustic criterion that allows modeling large-scale vortex motions of spots by an equivalent point vortex system;
definition of an acoustic criterion that allows modeling large-scale vortex motions of spots by an equivalent point vortex system; solving the possibility of modeling distributed vortices by point when constructing a sound source.
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The sound fields of several coherent vortex structures interacting
with each other were calculated using the moment model (MZS-model)
of the first and second orders. Sound fields as a result of vortex interaction are calculated using the Lighthill's acoustic analogy under Powell's formulation. It is shown that the computed characteristics
of the sound field substantially depend on the order of the moment model
describing the vortex structures. The spectrum of the sound field in the description of coherent vortices by point vortices is characterized by a single frequency band, which reflects the motion of the vortex centers of vortices (large-scale vortex movements). Taking into account the inner vortex dynamics (under the transition from the point to elliptic
representation of the vortex) leads to the expansion of spectrum and level increasing of calculated sound, which is the result of the
interaction of these vortex structures. It is shown that large-scale vortex movements can be modeled by point vortices by the analyzing low frequency band of the sound field. The presence of an upper frequency band in the sound field of interacting vortex spots does not allow us to describe the distributed vortices as point vortices when constructing a sound source, since such a simplification leads to a significant underestimation of the level of the calculated sound field. Since the internal dynamics of the vortices forming the flow leads to a significant increase in a sound field level, in order to reduce the noise emission of the eddy flow, its control should be aimed at reducing the eccentricity of the vortex cores.
Product Description
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Ilchenko Volodymyr M.
Ishakova Ludmyla V.
Gorskij Yurij V.
Konovalyuk Tetyana P.
Kot Olexandr O.
Krasnopolskaya Tatyana S.
Pechuk Evgen D.
Filimonov Vitaly Ju.
Jarosh Dmytro V.
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2024-01-28
