Vortex ring
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Vortex ring |
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HOMESite schemaIntroduction Vortex
ring
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The artificially-generated vortex rings are principally inherent in activity of our institution (as its name implies � SPA �Typhoon� or its scientific body �Institute of Experimental Meteorology� (IEM)). The question arises as to whether such studies (being rather enthusiastic) could yield presently any returns. From this standpoint I shall try to advance arguments in favor of practicality of vortex rings. Fig. 1 The TVR rise at wind shear over the tower site. |
Usually, the vortex rings are perceived as exotic and impressive structures being of purely cognitive interest but of no practical significance. On the other hand, there are researchers, even among the famous scientists, who overestimate practical importance of their ideas and devices. |
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Until recently, the
vortex rings have been mainly of academic interest and studied generally
under laboratory conditions in the calm homogeneous medium. The dynamics
and features of meter-sized vortex rings were first investigated regularly
on the IEM meteorological test ground and the answers were obtained to
major practical issues (see the
thesis synopsis). Starting with the brief story about vortex rings,
I shall come then to both the advisability of using the vortex as a probe
in the lower atmospheric layers and outlook for other applications of
the vortex rings. |
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The vortex rings are commonly met in nature
having frequently the appearance of isolated structures. A skilled smoker
can easily make the small-sized vortex rings � our laboratory assistant
demonstrates such rings ( see on the slide). Fig. 4 Fall of a tinted drop in water |
 Fig.3 Laboratory technician Volodya is a master smoker |
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The vortices are developed when light gas or intensely heated air are rising in the atmosphere due its buoyancy. On the video pictures one can see the intense thermal transforming finally into a ring. These experiments were made under the direction of V.N.Ivanov and V.Ya.Korovin in the late 70s. The most vigorous vortex is formed with lifting a nuclear explosion cloud. On the photo from the book �Meteorology and Nuclear Energy� shown is the initial stage of vortex development after explosion of a hydrogen bomb on one of the Pacific atolls. Many other spectacular pictures could be demonstrated with laminar and turbulent vortex rings in air and water. Fig. 5 Explosion in air generates the intense thermal which transforms then into a ring vortex |
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The vortex rings are the
classic objects of aero- and hydrodynamic studies. Because of their physical
fundamentality and complexity, stability, reproducibility, and occurrence,
the vortex rings have attracted considerable interest over a century.
Vortex rings fixed the attention of the eminent physicists in 19-20-th
centuries: Maxwell, Reynolds, Zommerfeld, academicians M.A.Lavrent�ev
and Ya.Zeldovich. Lord Kelvin, the discoverer of an electron, tried to
represent an atom as the oscillating ring vortices. Now, some competent
researchers are inclined to believe that the vortex rings are some �structural
elements� of turbulence. The vortex rings have been recently found in
the first sector of the submerged jet and in the hydrodynamic wake past
an obstacle. They are often associated with the coherent structures in
turbulent flow. |
Fig. 6 The thermonuclear explosion at Bikini atoll |
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The motion of vortex rings
in ideal liquid was considered theoretically in �Hydrodynamics� by J.Lamb
which had little in common with the actual ring behavior. The researchers
from the Novosibirsk Institute of Hydromechanics under the direction of
M.A.Lavrent'ev made the greatest contribution to comprehension of development,
structure and features of the actual vortex rings. The same is true of
the experimental works of T.Maxworthy in the mid-70s. Their findings,
particularly the thesis of V.F.Tarasov, have formed the scientific basis
for my applied studies. |
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Last updating: on September, 28, 2005
The contact information |
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| The post address | 249020, Russia, Obninsk the Kaluga region, st. Lenin
82 |
| Phone, fax | 7(08439)52045, 7(08439)71824 |
