Abstract:
A wind mitigation system for attachment to a residential or commercial building to mitigate wind suction forces known to damage roof structures, and to harness wind energy to create electricity. The system may comprise one or more rotating cylinders which make use of the Magnus effect, a scientific phenomenon involving air flow over a rotating cylindrical object. Rotating Magnus cylinders are installed on the roof, preferably at or near the roof-wall junction of a building in order to provide the greatest suppression of perpendicular wind forces and resulting vortices. Wind flowing across the Magnus cylinders creates a downward force that is transferred to the roof by structural support brackets. The downward force counters the upward lifting forces generated by high winds so as to prevent uplifting of the roof structure. Electrical energy is generated from oscillations resulting from variations in wind speed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of provisional U.S. Patent Application Ser. No. 61/311,503, filed Mar. 8, 2010. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     N/A 
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights rights whatsoever. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a wind damage mitigation and the harnessing of wind energy, and more particularly to a device which mitigates wind damage by applying a downward force to roof structures while simultaneously harnessing wind forces to produce energy. 
     2. Description of the Background Art 
     Every year, billions of dollars are spent on repairs due to wind damage. Many of these repairs involve damage to roofs or roof replacement entirely. The problem is especially prevalent in geographic locales which are subject to extreme weather patterns (i.e. Florida). Once a roof is damaged, the interior of a house may become exposed to the harsh elements often resulting in additional damage. The biggest concern for homeowners living in these harsh environments is preventing damage to roof structures. 
     High winds are known to create upward lift forces on roof structures on residential and commercial buildings. The sharply angled nature of the roof-wall junction causes swirling that creates an upward suction effect which acts on the roof. The upwardly pulling suction force becomes very powerful in high winds and is often powerful enough to break away a roof entirely from the rest of the house. The incidence of the suction phenomenon is greater when the wind is projected onto a flat-roofed building. The uplift force is considered to be the greatest force subjected to a building and is a common reason for failure. 
     The suction force is created when wind is acting in a generally perpendicular onto the side of a building. When the wind acts on the corner at the roof-wall junction, a conical-shaped vortex is created along the edges of the roof. The nature of the vortex creates a low pressure field along the roof-wall junction of a house. This phenomenon is responsible for the large uplifting force on the roof. 
     In view of the damage caused high winds, the background art reveals a number of attempts directed to adapting structures with wind mitigation systems. For example, U.S. Pat. No. 6,601,348, issued to Banks et al., discloses a system for mitigating wind suction atop a flat or slightly inclined roof. Numerous embodiments of a rooftop apparatus are provided which work similar to a spoiler on a car. The strategic placement and shape of an elongated apparatus mitigates the wind&#39;s suction forces created by strong lateral gusts projected onto the building. Once installed, the apparatuses are static and do not move. They simply redirect the flow of fluid (wind) to pass over the rooftop. 
     One shortcoming of this system is its fixed nature that is not capable of being set into motion. Dynamic movement of such a structure would maximize efficiency by not only redirecting the flow of the wind, but also using the wind to project a downward force on the roof, thus countering the suction effect. Furthermore, the wind contains an abundance of energy which is simply wasted when it is redirected and allowed to flow over the roof of a house. Therefore, it may be contemplated that such an apparatus could capture the energy of the wind as well. 
     Accordingly, there exists the need for new and useful devices and systems for mitigating the uplift effect caused by wind forces on a roof. Furthermore, there exists a need for a wind mitigating device that can be retrofitted onto a building and need not be installed while the structure is being built. Finally, there exists a need for a system which not only mitigates wind forces on a building, but harnesses wind forces in order to create energy. It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. In view of the wind mitigation systems in existence at the time of the present invention, it was not obvious to those persons of ordinary skill in the pertinent art as to how the identified needs could be fulfilled in an advantageous manner. The instant invention addresses this unfulfilled need in the prior art by providing a wind mitigation and harvesting system as contemplated by the instant invention disclosed herein. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a wind mitigation system for attachment to a residential or commercial building to mitigate wind suction forces and to harness wind energy to create electricity. The system may comprise one or more rotating cylinders which make use of the Magnus effect, a scientific phenomenon involving air flow over a rotating cylindrical object. In accordance with a preferred embodiment, Magnus cylinders are installed on the roof, preferably at or near the roof-wall junction of a building in order to provide the greatest suppression of perpendicular wind forces and resulting vortices. Wind flowing across the Magnus cylinders creates a downward force that is transferred to the roof by structural support brackets. The downward force counters the upward lifting forces generated by high winds so as to prevent uplifting of the roof structure. Alternate embodiments further function to generate electrical power from movement and/or oscillations of the Magnus cylinder structures thereby producing environmentally friendly electrical energy without presenting a hazard to wildlife, such as birds. 
     Accordingly, it is an object of this invention to provide a wind mitigation device and system which reduces the upward forces on a rooftop that are created by strong winds. 
     It is also an object of this invention to provide a wind mitigation device that harnesses the winds power to produce electricity. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Preferred embodiments of the invention will now be described in further detail. Other features, aspects, and advantages of the present invention will become better understood with regard to the following detailed description, appended claims, and accompanying drawings (which are not to scale) where: 
         FIG. 1  is a perspective view illustrating the wind&#39;s effect on a building with a flat roof; 
         FIG. 2  is a perspective view illustrating the wind&#39;s effect on a building with a sloped roof; 
         FIG. 3  is a perspective view of a building with the claimed invention installed at the roof-wall junction; 
         FIG. 4  is a cross sectional view of the cylinder of the claimed invention illustrating the Magnus effect force created by the flow of wind over the cylinder; 
         FIG. 5  is a side elevational view of another embodiment of the claimed invention installed atop a building with a flat roof; 
         FIG. 6  is a side elevational view of another embodiment of the claimed invention installed atop a building with a sloped roof; and 
         FIG. 7A  is a perspective schematic illustration of an alternate self-powered embodiment wherein the cylinder axel is adapted with horizontal and vertical cables that harness translational movement; 
         FIG. 7B  is a top view schematic illustration of the alternate self-powered embodiment; 
         FIG. 8A  is a side view illustration of a wind power apparatus adaptable to function as a Magnus effect apparatus in accordance with the present invention; 
         FIG. 8B  is a side view illustration thereof showing initial deployment of a Magnus surface; 
         FIG. 8C  is a side view illustration showing the Magnus surface fully deployed; 
         FIG. 9  is a perspective view of an embodiment of the present invention configured with a track to allow horizontal translation and a telescopic vertical support to allow for vertical translation; and 
         FIG. 10  is a schematic illustration of an alternate embodiment system of the present invention adapted with a thermoelectric generator. 
     
    
    
     A better understanding of the invention will be obtained from the following detailed description of the preferred embodiments taken in conjunction with the drawings and the attached claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference now to the drawings, and in particular to  FIGS. 1 through 6  thereof; a system for mitigating the suction effect (i.e. lifting forces) of wind and harnessing the force of wind to generate electricity employing the principles and concepts of the preferred embodiment of the present invention, and generally designated by the reference numeral  10  will be described. 
     With reference to  FIG. 1 , a building  10  with a flat roof  11  is shown. The arrows  30  indicate the direction of the wind as it is projected onto the building. The perpendicular flow of the wind  30  forms vortices  32  which create an uplifting force on the roof. This phenomenon is referred to as the suction effect and it is induced directly by the vortices  32 . The suction effect is the primary mode of failure of roof tops during storms with heavy winds.  FIG. 2  illustrates the effects of heavy winds on a building with a slightly pitched roof. 
     With reference to  FIG. 3 , the preferred embodiment of the present invention  10  is shown. An elongate, generally hollow cylinder  10  is mounted to a support structure, such as brackets attached to the side of the building. Cylinder  10  is mounted on the brackets in such a way that it is capable of axial rotation. An electric motor (not shown) is coupled to the cylinder which causes it to rotate in a clockwise direction at various speeds. The purpose of the rotation is to create an incidence of the Magnus effect as air passes over the cylinder. 
     The Magnus effect becomes better understood with reference to  FIG. 4  which shows a free-body-diagram of a cross section of the rotating cylinder. The force of the wind  30  projected onto the spinning cylinder  10  creates downward force, illustrated by reference number  34  that is generally perpendicular to the direction of the airflow. Cylinder  10  is rotated in a predetermined direction (e.g. clockwise or counter clockwise) depending on the airflow direction to produce a downward force as illustrated in  FIG. 4 . Because the cylinder  10  is rotated in a clockwise direction, that force  34  is projected downward due to the right to left wind direction depicted in  FIG. 4 , thereby pushing the cylinder  10  down. This downward force is preferably applied to the roof structure so as to provide resistance to uplifting forces. As should be apparent, the downward force may be applied to the roof structure via any suitable load transferring structure. 
     Another embodiment of the present invention is shown in  FIG. 5 . As shown in  FIG. 5 , the cylinder  10  is horizontally supported in vertically spaced relation with the roof. Thus the downward force created by the Magnus effect is transferred to the surface of the roof onto which cylinder  10  is installed. This force works to counter the upward suction force on the roof that is generated by heavy winds. 
     Another feature of the device illustrated in  FIG. 5  is the installation of an aeolian power generator  18  into the arms of the brackets which hold the cylinder  10 . This gives the cylinder  10  and a portion of the cylinder mount a certain degree of freedom to oscillate vertically within the mount. The power generators  18  convert these oscillations into electricity. The electricity can be used to power the motor that spins the cylinder  10  and/or may also be made available for consumption by the occupants of the building. Due to the inconsistent nature and incidence of wind gusts, the cylinder  10  will be caused to shift a greater displacement downward as the force of the wind  30  increases. This is a result of the spring-like resiliency of the aeolian power generator  18 . When the force of the wind  30  reaches a certain strength, the cylinder  10  will be pushed down as far as it possibly can in its ‘seat’. At this point, the downward force created by the Magnus effect will be transferred to the roof in order to counter the suction effect. 
     Power generators  18  are preferably incorporated into the cylinder mounting structures and configured to harness movements of the cylinder to generate electrical current. In accordance with this embodiment, the cylinder mounting brackets are adapted to allow the cylinder to oscillate with variations in wind speed. Power generators  18  are incorporated into the cylinder mounting structures and comprise electrical generators, preferably in the form of magnets and conductor windings. Either the magnets or windings are fixed with the other being disposed in movable relation such that natural oscillation of the cylinder causes relative movement between the magnets and windings so as to generate an electrical current. 
       FIG. 6  shows yet another embodiment of the present invention installed upon a sloped roof. As evidenced by the figures, the inventor contemplates that the brackets which hold the cylinder may be mounted to the surface of the roof itself, the side of the roof, or the side of the building. Given the varying nature of roof-wall junctures on different buildings, different arrangements may be contemplated to best suit a given application. Furthermore, the device need not be relegated to the edges of a roof. Referring back to  FIG. 2 , the vertex of a sloped roof creates another wind vortex which induces an uplifting force on the top of the roof as well. Therefore, the present invention may be installed at the highest point of a roof or any other point thereon. 
       FIGS. 7A and 7B  provide a schematic illustration of an alternate embodiment of an apparatus, generally referenced as  100 , that harnesses variations in wind forces to self-power cylinder rotation. Arrow  102  indicates the direction of the wind, and arrow  103  indicates the direction of cylinder rotation. A generally hollow cylinder  110  is mounted to a track  105  attached to a building.  FIG. 7B  provides a top view schematic illustration showing two generally identical cylinders, referenced as  110  riding on a track  105 . The cylinders  110  are mounted track  105  in such a way that they are able to rotate axially. Drag forces resulting from the wind blowing over a generally blunt object result forces that push cylinder  100  in a direction with the wind. There are two axial spools, namely a first spool  116  for winding and extension of cable  114  in response to horizontal movement, and two axial spools  118  for winding and extension of cable  116  in response to vertical movement. As wind pushes the cylinder in the direction of the said wind, the cable  114  unwinds from the spool, causing the cylinder to spin. As it spins, the Magnus Effect is allowed to be utilized, and downward force is encountered as the object moves in the direction of the wind. This in turn causes the cable from the vertical axis to unwind along the spool, increasing the rpm of the cylinder in the downward direction. A torsion spring  120  is axially connected to the spools in order that the spools will return to their original position. A significant aspect of this embodiment involves configuring the cylinder to rotate in the same direction (i.e. clockwise or counter clockwise) regardless of whether the cylinder is moving in the same or opposite direction of the wind so as to maintain the constant generation of a downward Magnus effect force. As the cylinders return to their original position, the same effect takes place on the opposite directions with the vertical and horizontal cables unwinding. The cables unwinding causing the cylinders to spin can in turn power a small generator from the revolutions of the cylinders. This generator can be used as a motor in the event of a windstorm. 
     In accordance with another embodiment, illustrated in  FIGS. 8 a -8 c   , there is a wind power device generally referenced as  200 , adapted for rapid conversion to a Magnus effect apparatus in accordance with the present invention.  FIG. 8 a    illustrates embodiment  200  wherein a wind powered device or wind turbine  202  is adapted with a spool  204  containing a sheet like material  206  wound thereon. Wind turbine  202  is preferably a Darrius type wind turbine, or any other suitable multi-blade wind turbine, and functions to generate electrical power by rotation about an axel  203  in a first mode of operation.  FIG. 8 b    illustrates a partial deployment of material  206  onto the wind turbine  202  from spool  204 .  FIG. 8 c    illustrates full deployment of material  206  onto wind powered device  202  thereby forming a cylinder capable of harnessing the Magnus effect in a second mode of operation. In a preferred embodiment, control means are provided to selectively deploy sheet material  206  onto wind turbine  202  in response to predetermined conditions or parameters. For example, wind turbine  202  may operate in wind power mode to generate electricity and convert, upon deployment of sheet material  206 , into Magnus effect operating mode in response to high wind speeds. Conversion to the Magnus effect operating mode would create a downward force that can be applied to the associated structure to enhance structural integrity of various building systems and components. 
       FIG. 9  is a perspective view of an embodiment of the present invention, generally referenced as  300 . In accordance with this embodiment, a cylinder  302 , is supported by a vertical cylinder support  304  in cantilevered relation therewith. Cylinder support  304  is slidably mounted to a generally horizontal track  306 . Cylinder  302  is preferably rotatably connected to cylinder mount  308  disposed on the upper portion of vertical support  304 . Cylinder mount  308  preferably includes a drive motor (not shown) adapted to cause cylinder  102  to rotate in a desired direction whereby cylinder  302  functions in accordance with the Magnus effect in response to naturally occurring atmospheric winds. Vertical support  304  preferably comprises upper and lower telescopically engaged sections, referenced as  304 A and  304 B, respectively. Upper section  304 A is affixed to cylinder mount  308  and lower section  304 B is in slidable relation with horizontal track  306 . The vertical cylinder support is preferably spring biased to a normal operating position, while allowing for horizontal oscillation. As noted above, vertical support  304  is comprised of telescopically movable sections  304 A and  304 B such that Magnus effect forces can be harnessed to generate electrical energy using an electrical generator associated with vertical support  304 . More particularly, in response to varying wind speed, the Magnus effect produces vertical oscillation of upper section  304 A relative to section  304 B is converted into electrical energy. The upper and lower sections are preferably spring biased to a normal operating position, while allowing for vertical oscillation. In addition, vertical support  304  is slidably mounted within horizontal track  306  and adapted to generate electrical energy from movement of vertical support  304  relative to track  306 . The relative movement of vertical support  304  relative to track  306  may be harnessed by a fore and aft cables wound about a spool as illustrated in  FIG. 7 . 
       FIG. 10  depicts yet another alternate embodiment, generally referenced as  400 , wherein heat associated with the hot roof surface is harnessed by a thermoelectric generator to produce electrical power which may be used by an electric motor to cause cylinder rotation, or by the inhabitants of the structure. As best illustrated in  FIG. 10 , Magnus cylinders  402  are rotatably connected to a generally vertically disposed supporting structure  404  and define generally open ends  403 . Supporting structure  404  includes a thermoelectric generator  406  which converts heat (temperature differences) directly into electrical energy, using a phenomenon called the “Seebeck effect” (or “thermoelectric effect”). Thermal conductors  408  conduct heat from the roof to thermoelectric generator  406 . Thermal conductors may comprise metal bars having a high thermal conductivity, or may comprise more complex heat transfer devices. A heat transfer coil  410  is housed within supporting structure  404  in thermal communication with thermoelectric generator  406  and disposed in the airflow path of air entering an air inlet  412  defined by structure  404 . Each cylinder  402  is preferably adapted with a fan blade  405  to move air through the cylinder for reasons more fully described herein. 
     Ambient air, referenced by arrows  414 , is drawn by fan blades  405  into inlet  412  defined by structure  404 . The air then flows across heat transfer coil  410  and through Magnus cylinders  402  before exiting the generally open ends  403  of Magnus cylinders  402 . Accordingly, the thermoelectric generator  406  is exposed to a temperature differential (e.g. ΔT) resulting from the relatively high temperature caused by conducting heat from the hot roof surface using thermal conductors  408  as compared with the relatively low temperature of the ambient air. As should be apparent, the temperature differential is maximized with structures having dark roofs. Thermoelectric generator  406  thus produces electrical power from this temperature differential, which electrical power may be used to drive rotation of Magnus cylinders  402 , or may be used by inhabitants of the structure. 
     The electrical power generation capability of the system may be enhanced by covering the external surface of cylinders  402  with flexible solar panels which capture and convert solar energy to electrical energy. A significant advantage of this embodiment results as the cylindrical solar panels are capable of capturing solar energy from various angles. 
     The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious structural and/or functional modifications will occur to a person skilled in the art.