Abstract:
A vortex generator for use in establishing air fountains, kinetic sculptures, or unique stage effects comprised of a circular planar stage upon the surface of which a central vertical updraft is created by forced swirling air emanating from a cylindrical plenum beneath the stage, the air exiting through a circular orifice and lip forming a circumferential flow restrictor encircling the stage.

Description:
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/235,014 filed Sep. 30, 2015. 
    
    
     BACKGROUND OF THE INVENTION 
     Over the years, artists have utilized common materials and objects as elements in dramatic sculptures and installations. Kinetic sculptural works have evolved in which circular focused arrays of fans have been assembled to generate invisible vortices of air, or “air fountains,” which in combination with lightweight, aerodynamic materials create startling dramatic, kinetic visages. Such kinetic sculptures, in addition to being aesthetic works of art, have been utilized in theatrical, dramatic, and/or musical performances to enhance the sensory experiences of viewers. 
     Various systems and methods for generating artificial tornados and other vortex phenomena have been disclosed in prior art patents including U.S. Pat. No. 5,591,765 to Gill et al., U.S. Pat. No. 3,589,044 to Morrison et al., and U.S. Pat. No. 5,096,467 to Matsui. None have involved kinetic sculptures and/or generators of special aesthetic effects. 
     The present invention is directed to new and improved vortex generators for kinetic artwork and special visual effects generators. 
     BRIEF SUMMARY OF THE PRESENT INVENTION 
     The present invention is a vortex generator that produces a vortical updraft above the center of the circular flat top surface of the base of a kinetic sculpture or stage, in which deployed lightweight materials ascend from the base or stage and fly freely in the generated vortex. The flying materials ascend and descend endlessly above the flat base of the new vortex generator. The new invention comprises a disc-shaped, drum-like enclosure, with a series of internal fans or blowers generating a laminar airflow that emanates from a circular peripheral orifice established around the perimeter of the top, flat circular surface of the generator. Airflow from the circular perimeter orifice is directed horizontally across the flat top surface of the base toward the center or slightly off center of the circular base. The generated airflow, upon reaching the center of the circular base, forces those deployed lightweight materials within the system to ascend either directly straight up or upwardly in a vertical, spiral pattern in the generated vortex. The upward moving vortex has a predetermined degree of rotational spin around a vertical axis located at the center of the circle, the precise rotation depending on the fan arrangement and power. The new vortex generator may be made at virtually any scale for use as base for a kinetic sculpture or special effect generator; part of an architectural installation; built into a larger flat surface; or as a round, movable stage unto itself. 
     In a preferred iteration, the disc shaped, drum-like enclosure has a lower circular opening into which a number of centrifugal fans are mounted, blowing air into the enclosed plenum and pressurizing it. These fans are focused outwardly towards the perimeter wall of the enclosure at predetermined angles which generate rotational spin in the upward rising vortex generated above the top surface. Air that emanates from the fans passes around interior baffles that function to control air pressure and airflow within the drum-like enclosure before exiting at the upper periphery in a laminar flow directed toward the center of the circular disc-like top surface where the opposing flows from around the entire periphery combine to generate a vortex. 
     To establish a kinetic sculpture or to create a special visual effect, lightweight materials are introduced externally within the generated air flow. These lightweight materials ascend and fly and whirl about in a variety of specific patterns in the vortex depending upon the specific angles of the deployed fans; the size of the base; the volume and velocity output of each fan and the specific aerodynamic properties of the deployed materials. 
     A dark reflective black mirror or other flat, smooth surface may be included at the top surface of the vortex generator so that the images of the launched flying materials, including for example mylar or shimmery fabrics, are reflected by the mirror. With no visible means of propulsion, viewers of kinetic sculptures utilizing the new vortex generator as a base will observe a “dance” of the lightweight fabrics above the base, their reflections in the mirror top, and the ambient of light and shadows that are created as they fly. 
     For a better understanding of the present invention and a greater appreciation of its attendant advantages, reference should be made to the following detailed description taken in conjunction with the accompanying drawings and illustrations. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the new vortex generator embodying the principles of the present invention; 
         FIG. 2  is an exploded perspective view of the new vortex generator; 
         FIG. 3  is a cross-sectional view taken on plane  3 - 3  of  FIG. 2  of the new vortex generator schematically showing the air flow and swirling fabrics in the generated vortex; 
         FIG. 4  is a cross-sectional view taken on plane  4 - 4  of  FIG. 2  showing internal support structure; 
         FIGS. 5 and 6  are enlarged cross-sectional views taken on planes  5 - 5  and  6 - 6 , respectively, of  FIG. 2  of the vortex generator; 
         FIG. 7  is a top plan view of the arranged blowers and support elements of the vortex generator; 
         FIGS. 8-11  are perspective views of “dancing” fabrics forming kinetic sculptures in accordance with the principles of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to  FIGS. 1-7 , a preferred embodiment of the vortex generator of the invention generally includes a lower base support structure  10  having outer cylindrical wall  11 , central column  45 , and radial arms  44 , which support an extended round stage  20  above a plenum chamber  60  formed in part by a planar upper disc  20  and a spaced lower disc  30 . The discs  20 ,  30  are joined by an inner cylindrical wall  21 , which is completed by and mounts twelve centrifugal blowers  22  on blower panels  23 , and an outer cylindrical wall  31 , to form the drum-like plenum chamber  60 . A circumscribing ring  50  of L-shaped cross section having an inwardly projecting, flat circumferential lip  51  is mounted at the top of the wall  31 . Cylindrical filler  52  is superimposed on wall  31  flush with ring  50  to provide a smooth aesthetic exterior as shown in  FIG. 6 . A dark, flat, reflective mirror  27  is superimposed on the disc  20  to enhance the special visual effects created when flyable materials are inserted into the vortex generated by the unit. An exploded perspective view of the assembled vortex generator is shown in  FIG. 2 . 
     The upper disc or stage  20  advantageously may have a flat shiny surface or as shown mounts the separate reflective mirror  27 , and is supported by extended radial arms  44 , abbreviated arms  47 , central column  45 , and vertical posts  46  extending between the discs  20  and  30 . The arms  44  engage and support the underside of discs  20  and  30  as shown in  FIG. 4  and may include circular and rectangular cutouts to reduce their weight and permit circulation of air in the base  10 . 
     In accordance with the principles of the invention, and as shown in  FIGS. 2, 3 and 6 , the upper disc  20  is of slightly smaller diameter than that the diameter of the outer wall  31  to form along therewith and with the lip  51  a narrow circular peripheral opening which functions as a flow constrictor  53  at the upper disc surface or stage of the drum-like plenum  60 . 
     As shown in  FIGS. 3, 5 and 6 , ambient air enters the support  10  through ports  12  formed in outer wall  11  and thereafter flows into the blower inlets  28 . The air passes through the blower  22  and is pressurized and expelled through outlets  24  to pressurize the plenum  60 . The pressurized air then passes over an upwardly extending baffle  62 , and then between a downwardly extending baffle  61  and a convex circumscribing deflector  63  formed by molded silicone at the intersection of the disc  30  and wall  31 , before exiting the plenum  60  at the peripheral flow constrictor  53 . The confluence of the inwardly directed streams of the blowers  22  at the upper surface of the mirror  27  on disc  20  creates the vortex. 
     As shown in  FIGS. 3 and 6 , the downwardly projecting, circumscribing baffle  61  is supported at the periphery of the upper disc  20 , while the upwardly projecting baffle  62  is supported on the lower disc  30 . The baffles are of a height approximately half of the spacing of the upper and lower discs (the depth of the plenum chamber  60 ). The baffles  61 ,  62  serve to control the airflow and the pressure within the plenum chamber  60 . 
     The blower panels  23  each mount a centrifugal blower  22 , advantageously a conventional air mover with a capacity of approximately 2000-4000 CFM. As shown in  FIGS. 2, 3 and 6 , the blowers  22  are supported by the blower panels (“boxes”)  23  and have rectangular outlet openings  24  which direct the air flow from each blower  22  into the plenum  60  at a predetermined angle with respect to the radius of the plenum to generate a laminar flow L ( FIG. 6 ) as the air exits the plenum  60  through the flow constrictor  53 . The blower panels  23  are directly fastened (by bolts not shown) to and supported by the upper disc  20 . 
     As shown and described above and illustrated in  FIGS. 3 and 6 , the blowers  22  issue individual pressurized streams of air which enter the plenum  60  at the inner cylindrical wall  21 . The blower air travels radially outwardly over the lower baffle  62  and the upper baffle  61  to exit the plenum  60  at the narrow circumferential opening of the flow constrictor  53  formed by the flat peripheral lip  51  and the upper edges of the cylindrical wall  31  and peripheral edges  26  of the upper disc  20 . 
     When the pressurized air reaches the mirrored upper disc surface  27 , it is in the form of a continuous laminar flow L directed radially inwardly to the center of the upper disc surface. In accordance with the invention, the radially inwardly directed flow from the peripheral edges converges at the central portion of the upper disc and interacts to create a vortex the characteristics of which can be adjusted or otherwise fine-tuned by changing the air pressure within the plenum. 
     To establish a kinetic sculpture or air fountain such as shown in  FIGS. 8-11 , lightweight elements  80 ,  81 ,  82  or other lightweight flyable material of predetermined size, shape, color, number and/or aerodynamic property such as, for example, confetti, feathers, Styrofoam, “peanuts,” balloons, vapor fog, or artificial snow flakes are introduced into the vortex where the materials will fly about in generally repeating patterns. The aesthetic effects of the kinetic sculpture may be enhanced by directional external lighting (not shown) and by the flat mirror  27  on the upper disc  20 . 
       FIGS. 2-7  herein are illustrative and exemplary of the general proportions, arrangement, and sizing of an operative vortex generator embodying the principles of the present invention. It is to be appreciated however that variations may be made in creating vortex generators within the scope of the invention. The illustrated unit may be scaled to larger and smaller sizes. The plenum chamber  60  may be appropriately pressurized by an external air source, the output of which may be introduced into the plenum by ductwork or piping. The pressure and flow generated by the illustrated series of twelve centrifugal blowers may be created by an appropriate single blower source mounted internally. Other systems of fewer or more blowers may also be employed to pressurize the plenum as will be understood by those skilled in the art. For example, in an alternative version of the new generator, fans may be located remotely from the disc-shaped enclosure and the forced air may be directed to the enclosure through a system of ducting. The flow restrictor may be formed at the periphery of the inner wall in such an arrangement. Additional louvers may be employed to generate airflow for rotational spin. The mirror may be omitted when the stage surface is shiny or otherwise reflective. 
     It should be understood, of course, that the specific form of the invention herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure.