1. Technical Field
This invention relates to a method and apparatus for producing vortex rings of gas in a fluid medium. More specifically, the apparatus may operate automatically with a finite supply of a gas, or it may be connected to a supply of gas such that the vortex rings are generated automatically and continuously.
2. Description Of The Prior Art
Vortex rings are aesthetically pleasing with behaviors and aspects that are very interesting to many people. A smoke ring, which is a form of a vortex ring made from a visible form of gas, can be made to traverse a small room, and even extinguish a candle flame several feet away from where the smoke ring was generated. However, vortex rings are not limited to smoke rings. A vortex ring of identical size to a smoke ring may be made of air instead of smoke. Such a ring comprises similar characteristics to a smoke ring, and can also travel invisibly across the same room and extinguish a candle flame. Vortex rings have been studied by students in the field of fluid dynamics, which is an important part of airplane design and other engineering disciplines.
Most people have only seen a vortex ring in the form of a smoke ring. However, there is another form of a vortex ring that can be studied and enjoyed without involving the many known dangers and drawbacks associated with the creation of smoke rings. This alternative form of a vortex ring is a ring made of a gas and travels through a liquid medium, usually in an upward vertical direction. When created out of air within a medium of water, these vortex rings have also been known as bubble rings. They are enjoyable to play with and to study, although before this invention they have not been easy for the average person to generate.
Dolphins have been known to generate bubble ring type vortex rings, possibly for the entertainment and enjoyment of the exercise. However, these vortex rings are not readily available for viewing by humans, and dolphins have only rarely been captured on film creating bubble rings. The turbulence which appears in the wake of a jet plane, and which is dangerous to small planes that travel too close, will sometimes be in the form of ordinary vortex turbulence, which is similar to vortex rings. Vortex turbulence from planes is ordinarily invisible, so it can be challenging for engineers and especially engineering students to visualize how this effect occurs. Accordingly, there are several reasons why it is desirable to have a way to create vortex rings in a form that can be easily observed, studied, learned from and enjoyed.
There are several recent U.S. patents which disclose different mechanical apparatus to aid in the production of vortex rings. In general, each of these patents relate to the generation of vortex rings in a fluid environment, such as water, with the use of air as the gas. For example, U.S. Pat. No. 5,947,784 to Cullen teaches an apparatus for use by a human being in a fluid immersed environment. The apparatus comprises an elbow shaped tool with an elongated horizontal portion, and an elbow leading to a short vertical portion. At the end of the vertical portion, the apparatus includes a valve assembly. The elongated portion of the apparatus allows air to exit the apparatus away from the user's face and hands, so that the air and water near the short vertical portion is not exposed to any turbulence or obstacles. The configuration of the valve body that closes when the user stops blowing air through the elongated portion causes the bubble of air that is released to be one large bubble of air, and helps produce the toroidal configuration of the vortex rings. In general, the valve assembly responds to short bursts of air through an elongated passageway to produce vortex rings. Alternatively, the elongated section of the apparatus may be connected to a source of gas under pressure. The introduction of a burst of gas under pressure causes the body of the valve to momentarily be unseated thereby allowing a burst of gas to escape and produce the toroidal shaped vortex ring. Accordingly, the Cullen patent requires a person to be immersed under water or for a gas under pressure to deliver short bursts of air to momentarily unseat the valve and produce a vortex ring.
U.S. Pat. No. 4,534,914 to Takahashi et al. teaches an apparatus for producing vortex rings. The apparatus uses an accumulator in the form of a cylindrical cup, wherein gas enters the accumulator and exits through an outlet affixed with a nozzle. When the accumulator is in a non-operating position, the valve member is urged by a coil spring toward the gas outlet, causing a seal of the outlet. However, in order to produce the vortex rings, a gas under pressure is introduced to the accumulator thereby causing an increase in the pressure in the interior chamber of the accumulator. The pressure of the gas causes the diaphragm to be outwardly inflated against surrounding water pressure and the force of the spring, which altogether takes the valve member out of contact with the gas outlet and discharges a pocket of gas through an exit nozzle. The gas stored in the accumulator is discharged into the nozzle which is closed by water pressure so that the nozzle is quickly opened and then closed again. Accordingly, the Takahashi et al. patent requires gas under pressure to be supplied to a chamber, and based upon the pressure of the gas the valve is unseated resulting in the generation of a vortex ring.
U.S. Pat. No. 6,736,375 to Whiteis teaches an apparatus for producing vortex rings. The apparatus includes a base and a moveable lever. Gas is received in a pocket on one side of the lever through a gas inlet. When the pocket reaches capacity, the buoyancy of the gas tilts the lever and the gas is released from an associated exit nozzle. A pair of stops are provided to define vertical displacement limits of said lever. Although the Whiteis patent does not require gas to be delivered under pressure to produce the vortex rings, it does require vertical displacement of the lever that produces the vortex shaped ring.
Other designs besides this one and U.S. Pat. No. 6,736,375 to Whiteis all require pressurized air, either low pressure (Cullen) or higher pressure (Takahashi.) It is because this design uses a trickle of air at no pressure that it can be used with a finite air supply and operate automatically.
Accordingly, what is desired is an apparatus for generating vortex rings which eliminates the need for supplying gas under pressure, and eliminates the necessity of moving parts. By mitigating or eliminating any mechanical parts that require displacement, the complexity and associated breakdown of such parts is removed.
In one aspect of the invention, an apparatus is provided to generate a vortex ring in a fluid medium. The apparatus includes two stationary and parallel bodies. The first body has a top surface and a bottom surface, with the bottom surface having a pocket formed extending to a first level and an entrance to an exit aperture formed at a second level. The exit aperture extends from the second level to the top surface of the first body. In addition, a gas inlet is provided in the first body to deliver gas to the pocket. Gas in the pocket forms into a cohesive unit prior to entry into the exit aperture to form the vortex ring.
In another aspect of the invention, a ring generator is provided. The generator includes a first stationary section defined by first and second exterior surfaces. The first exterior surface has an interior concave section that communicates with an aperture that extends between the exterior surfaces, and a conduit that extends from an exterior wall of the first section into the concave section. A toroidal shaped ring is formed after gas emerges from the aperture.
In a further aspect of the invention, a method is provided for generating a vortex ring in a fluid medium. Gas is delivered to a concave section formed in a first level of a bottom surface of a first stationary body. A first cohesive unit of gas is formed in the concave section and pulled to an exit aperture entrance when the volume of gas in the concave section exceeds capacity. A toroidal shaped bubble is formed from the first cohesive unit after it departs the exit aperture.
Other features and advantages of this invention will become apparent from the following detailed description of the presently preferred embodiment of the invention, taken in conjunction with the accompanying drawings.
A vortex ring is a cohesive ring of fluid or gas that is created in a fluid or gas medium and travels in a particular direction through that medium. The most well known forms of vortex rings are made of smoke generated by the burning of tobacco products. However, another common form of vortex rings are bubble rings that are created in water. One way to create a bubble ring is by releasing a pulse of air into water that is relatively free of turbulence. This most commonly well known method of creating bubble rings is referred to here as the common method, and can only produce bubble rings that travel upwards towards the surface of the water. These are known as standard bubble rings. Other bubble rings can travel horizontally through a fluid medium, but are not a subject of this invention.
There are other specific parameters which must be adhered to in order to produce a gas vortex ring within a body of water using this method. In general, to create a standard bubble ring, the pulse of air must be released into the water through an opening that points in an upward direction into the water. The opening may simply be an aperture within a flat surface that is horizontal with respect to the surface of the water, or it may be a nozzle. However, the opening should be round or comprise a similar shape. The pulse of air that is released through the aperture should originate from a relatively turbulence-free reservoir of air. Any turbulence that does exist within the supply of air as it is released through the aperture should be symmetrical to an axis traveling through the center of the aperture, and any turbulence added to the air by a valve that may be used to control the flow of air out of the apparatus should also be symmetrical to an axis traveling through the center of the aperture. Accordingly, the state of the air prior to exiting the nozzle is but one important factor.
The air that is released from the aperture should be in the form of a pulse that begins and ends suddenly. Furthermore, the air should be in the form of a unitary bubble prior to release, and not in the form of a trail or plurality of bubbles. The air should not be preceded by fluid, nor should the air be followed by fluid. Preceding or following fluid around the gas pulse introduces turbulence to the fluid area where the vortex ring should form thereby preventing the vortex ring from forming. In addition, the pocket of air, i.e. unitary bubble, prior to release through the aperture should be approximately five to twenty times the volume of an imaginary sphere, wherein the diameter of that sphere is the same diameter as the aperture through which the air is to be released. Alternative proportions of the size of the pocket of air in relation to the diameter of the aperture may be employed for generating vortex rings in a fluid environment.
The bubble ring will form after being released from the aperture. Like any stable vortex ring traveling through a liquid or gaseous medium, the volume of the air or gas in the ring rotates as it travels through the fluid medium. Gas adjacent to the outer edge of the ring moves in an upward direction at a slower pace than the ring's overall upward movement, and the gas adjacent to the inside of the ring moves upward faster than the ring's overall vertical movement. Accordingly, if an observer ignores the ring's overall upward movement through the water, a speck of dust that was in the air of the ring near the surface of the ring would appear to spin, appearing first adjacent to the external edge of the ring, then adjacent to the bottom of the ring, then adjacent to the inside edge of the ring, and then adjacent to the top of the ring, repeating the pattern accordingly. The spin of the air then imparts a similar spin to the water immediately around the bubble ring, which adds to the stability of the bubble ring.
A bubble ring's spin is caused by the ring's movement through the water, and by the fact that the outside edge of the ring has a greater surface area than the inside edge, and is therefore more greatly affected by the friction created as a gas moves through the water. The spin makes the ring a stable object that enables the bubble to maintain its shape while traveling vertically in the water. As the ring travels toward the surface of the water, the diameter of the ring gradually increases. In general a bubble ring will maintain its shape until it hits the surface of the water, or until the diameter of the ring grows too large, at which time it becomes unstable and breaks up into ordinary bubbles. Accordingly, the characteristics of the water and gas prior to release through a round or near round opening are critical characteristics for forming a vortex ring in a fluid medium.
The concave surface 28 and bridge 48 can have a smooth surface, but the device will successfully create bubble rings more often if the two surfaces 28 and 48 have a rough texture, or by creating the surfaces with a very fine pattern of lines or cross hatching. This type of surface is less sticky to the air that will become the bubble ring, so the air slips off the surface more readily once the air starts flowing out the exit aperture.
The concave surface 28 is designed to accommodate the gas and to move the gas toward the exit aperture 40. Both the interior concave surface 28 and the exit aperture 40 are located on different vertical levels of the interior surface. More specifically, the concave surface 28 is at a first vertical level 62 at the first interior edge 46, and the entrance to the exit aperture 40 is at a second vertical level 64. The first vertical level 62 is shallower, or farther from the top of the device, than the second vertical level 64. When the volume of gas in the concave surface 28 exceeds the volume of the concave surface 28, the gas flows to the entrance of the exit aperture 40. At the same time as the gas reaches the entrance of the exit aperture 40, a vacuum is formed between the first body 20 and the second body 30. It is this vacuum that pulls the gas from the concave surface 28 to the exit aperture 40 as a single cohesive unit of gas, i.e. a single bubble. A toroidal shaped bubble, i.e. a vortex ring, is generated subsequent to the cohesive unit of gas leaving a top surface of the exit aperture 40. Once the toroidal shaped bubble is formed, gas continues to enter the concave surface 28 through the conduit 50 if the gas supply is continuous or if gas remains from a finite source. Accordingly, a toroidal shaped ring is formed from a supply of gas to a stationary body.
The second body 30 is shown parallel, or near parallel, to the first body 20. The second body includes four legs 32, 34, 36, and 38 to lift the second body from a tank surface. Similarly, the first body 20 is shown with four legs 52, 54, 56, and 58 to hold the first body 20 in communication with the second body 30. In one embodiment, the length of each of the sets of legs may be vertically adjusted. For example, the legs 32, 34, 36, and 38 of the first body may be lengthened, shortened, or even removed, and the length of the legs 52, 54, 56, and 58 may be extended or shortened to vary the distance between the first and second bodies, 20 and 30, respectively. Decreasing the distance between the first and second bodies, 20 and 30, respectively, without changing other factors makes the toroidal shaped bubbles emerge from the exit aperture at a slower velocity. However, if the distance between the first and second bodies is too small, the gas will depart the exit aperture too slowly and a toroidal shaped bubble will not form. Similarly, if the distance between the two bodies 20 and 30, respectively, is increased beyond the optimal distance a toroidal shaped bubble will not form because some of the gas in the concave surface 28 will enter the exit aperture 40 as a non-unitary mass. In addition to the spacing of the two bodies 20 and 30, the manner in which gas is delivered to the concave surface 28 is critical. Gas supplied to the concave surface 28 must be delivered at a slow steady rate, whether from a finite source or a pump. In one embodiment, a valve or other mechanical apparatus may be employed to control the rate of delivery of the gas to the concave surface 28. Accordingly, both the manner in which gas is delivered to the concave surface 28 and the distance between the two bodies 20 and 30 must be properly set to support generation of toroidal shaped bubbles.
In one embodiment, the diameter of the exit aperture is 5 millimeters, the distance between the first body 20 and the second body 30 is approximately 10 millimeters, the diameter of the outer edge of the bridge 48 is 30 millimeters, the diameter of the outer edge of the concave surface 28 is 60 millimeters, the depth of the concave surface 28 is 3 millimeters, and the difference in depth between the inner and outer edges of the concave surface 28 is 1 millimeter.
The apparatus disclosed herein mitigates the complexities of both mechanical apparatus and human intervention in generating toroidal shaped bubbles. Operation of the apparatus of
In addition to the reduction of human error and or intervention, the apparatus of the preferred embodiment does not require any complex mechanical systems for the generation of vortex rings. As shown in the prior art, apparatus for generating vortex rings generally comprise a plurality of membranes, resilient members, complex valve mechanisms, and/or turbulent fluid. However, the apparatus disclosed and claimed herein does not support mechanical movement of the first or second bodies subsequent to calibration. The apparatus of the preferred embodiment has a conduit to deliver gas from a gas source to a concave surface. Subsequent to calibration, the only element that has mechanical movement is the gas from the gas source to the concave surface, and from the concave surface to the exit aperture. Accordingly, the apparatus disclosed herein mitigates error and need for replacement of mechanically resilient members.
This design has no hinge or other moving part to get algae and other foreign matter stuck in it, which would prevent it from operating. It is easy to clean, and has no fragile parts. For these reasons, it is safe around many different types of animals where other designs would not be safe or allowed. This design does not use electricity or pressurized air, which are required for other designs, and are prohibited from many environments where fish and other animals are kept.
It will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. In particular, the apparatus may be adapted for functioning with a finite source of gas or from an infinite source of gas. The gas also may be in the form of non-pressurized air. Regardless of the source, the inventions are simple mechanical apparatus designed to produce vortex rings with minimal human intervention and minimal components that may be subject to failure over an extended period of time. Accordingly, the scope of protection of this invention is limited only by the following claims and their equivalents.
The present application is a continuation of U.S. patent application Ser. No. 11/085,991, now pending, filed Mar. 22, 2005, and titled “Apparatus For Creating Vortex Rings In A Fluid Medium”, which is hereby incorporated herein by reference.
Number | Date | Country | |
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Parent | 11085991 | Mar 2005 | US |
Child | 11743403 | May 2007 | US |