Patent Publication Number: US-2011070068-A1

Title: Fluid turbine devices and methods related to fluid turbine devices

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 12/568,091 filed Sep. 28, 2009. The entire disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to fluid turbine devices and methods related to fluid turbine devices. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Fluid turbines are commonly used to convert fluid movement into useful work. Often, fluid turbines are employed such that fluid flow contacts multiple blades thereby causing rotation of the blades. The rotation of the multiple blades may be converted into any useful motion, such as rotating an input of a generator to generate electricity. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     According to one aspect of the present disclosure, a fluid turbine device includes a vertical blade assembly having multiple blades, a shroud disposed at least partially about the vertical blade assembly and rotatable relative to the vertical blade assembly, a generator mechanically coupled to the vertical blade assembly, a sensing device positioned to determine an operating characteristic of the fluid turbine device, and a control operably coupled to the sensing device and configured to activate the generator based on the sensed operating characteristic of the fluid turbine device. 
     According to another aspect of the present disclosure, a wind farm includes a structure and multiple fluid turbine devices supported by the structure. 
     According to yet another aspect of the present disclosure, a fluid turbine device includes a vertical blade assembly having multiple blades, a shroud disposed at least partially about the vertical blade assembly and rotatable relative to the vertical blade assembly, the shroud being structured to deflect a first portion of a fluid flow from a return path of the vertical blade assembly and to permit a second portion of the fluid flow to enter a drive path of the vertical blade assembly, multiple generators, a speed sensor disposed relative to the vertical blade assembly to determine the rotational speed of the vertical blade assembly and a control operably coupled to the speed sensor and configured to activate one of the multiple generators whenever the sensed rotational speed exceeds a predetermined speed, until each of the multiple generators are activated. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a perspective view of a fluid turbine device according to one example embodiment of the present disclosure. 
         FIG. 2  is a perspective view of the fluid turbine device of  FIG. 1 . 
         FIG. 3  is a plan view of the fluid turbine device of  FIG. 1  showing fluid flow represented by arrows. 
         FIGS. 4A-D  are exploded views of the fluid turbine device of  FIG. 1 . 
         FIG. 5  is a perspective view of a fluid turbine device having a vertical blade assembly configured to rotate clockwise according to another example embodiment of the present disclosure. 
         FIG. 6  is a sectional view of a fluid turbine device including a vertical blade assembly having multiple chambers according to yet another example embodiment of the present disclosure. 
         FIG. 7  is a perspective view of a fluid turbine device including a rudder according to another example embodiment of the present disclosure. 
         FIGS. 8A-B  are partial perspective views of a fluid turbine device including a steering mechanism according to another example embodiment of the present disclosure. 
         FIG. 9  is a perspective view of a shroud according to one example embodiment of the present disclosure. 
         FIG. 10  is a block diagram of an electrical system including a grid according to another example embodiment of the present disclosure. 
         FIG. 11  is a block diagram of an electrical system including a battery according to yet another example embodiment of the present disclosure. 
         FIG. 12  is a perspective view of a billboard assembly according to one example embodiment of the present disclosure. 
         FIG. 13  is a plan view of an exemplary embodiment of a fluid turbine device in which fluid flow is represented by arrows. 
         FIG. 14  is a plan view of the fluid turbine device of an exemplary embodiment of a fluid turbine device having multiple generators and a vertical blade assembly coupled to the generators via a 50:1 gear. 
         FIG. 15  illustrates an exemplary embodiment of a fluid turbine device in which fluid flow is represented by the arrow and offset from a leading edge of a vertical blade assembly of the fluid turbine device. 
         FIG. 16  illustrates the fluid turbine device of  FIG. 15  after the vertical blade assembly is oriented into the direction of the fluid flow. 
         FIGS. 17A-B  illustrates the vertical blade assembly of  FIG. 15  being oriented clockwise and counter-clockwise relative to the direction of the fluid flow. 
         FIG. 18  is a block diagram of an exemplary embodiment that includes two fluid turbine devices coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus. 
         FIG. 19  is a block diagram of an exemplary embodiment that includes four fluid turbine devices coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus. 
         FIG. 20  is a block diagram of an exemplary embodiment that includes seven fluid turbine devices coupled and/or ganged together, for operating collectively and/or simultaneously on stacked upper and lower platforms, structures, or other mounting apparatus. 
         FIG. 21  includes a block diagram of an exemplary embodiment that includes two vertically stacked rows of fluid turbines devices coupled and/or ganged together, for operating collectively and/or simultaneously on stacked platforms, structures, or other mounting apparatus. 
         FIG. 22  includes a block diagram of an exemplary embodiment that includes three vertically stacked rows of fluid turbines devices coupled and/or ganged together, for operating collectively and/or simultaneously on stacked platforms, structures, or other mounting apparatus. 
         FIG. 23  is a block diagram of an exemplary embodiment that includes eight fluid turbine devices coupled and/or ganged together in a heptagonal configuration, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus. 
         FIG. 24  is a block diagram of an exemplary embodiment that includes four fluid turbine devices coupled and/or ganged together in a triangular configuration, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus. 
         FIG. 25  is a block diagram of an exemplary embodiment that includes twelve fluid turbine devices coupled and/or ganged together in a rectangular array that includes 3 rows and four columns, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus. 
         FIG. 26  is a perspective view illustrating an exemplary embodiment in which a plurality of fluid turbine devices are supported by a framework or structure having pillars or vertical support members with an airfoil configured to direct laminar flow through the structure thus reducing turbulence. 
         FIG. 27  is a perspective view illustrating an example of a pillar or vertical support that that may be used in the structure shown in  FIG. 26 . 
         FIG. 28  is a perspective view illustrating an exemplary embodiment in which a plurality of fluid turbine devices are supported by a structure. 
         FIGS. 29A-B  are perspective views of a fluid turbine device according to another example embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
       FIGS. 1 and 2  illustrate one exemplary embodiment of a fluid turbine device  100  suitable for practicing one or more methods disclosed herein. It should be understood, however, that the teachings of the present disclosure are not limited to the example fluid turbine devices, wind farms and systems described below, and that other embodiments of fluid turbine devices, wind farms and systems may employ one or more aspects of the methods of the present disclosure. 
     The fluid turbine device  100  includes a vertical blade assembly  102  having multiple blades  104  and a shroud  106 . The shroud  106  is rotatable relative to the vertical blade assembly  102 . The shroud  106  includes a leading edge portion  108  for deflecting a portion of a fluid flow from entering a return path of the vertical blade assembly  102 . The shroud  106  also includes a portion  110  defining multiple openings  112 . When fluid flows relative to the fluid turbine device  100 , a pressure differential is generated between a compartment  114  and an area adjacent the multiple openings  112 . The pressure differential (and Bernoulli&#39;s principle) provides conditions for fluid flow from the compartment  114 . In some embodiments, the shroud  106  defines at least a portion of an airfoil shape. Accordingly, the multiple openings  112  permit fluid flow from within the compartment  114  defined by the vertical blade assembly  102  to exhaust out of the return path. It should be appreciated that a different number and/or configuration of openings may be defined in one or more portions of a shroud to adjust fluid flow through the shroud, thereby adjusting fluid flow relative to a fluid turbine device to, for example, alter fluid flow turbulence relative to the fluid turbine device. 
     As shown in  FIG. 3 , the leading edge portion  108  of the shroud  106  is oriented in the direction of the fluid flow. In this particular embodiment, the fluid flow is wind. In other embodiments, a different fluid, e.g., water, etc., may be utilized by a fluid turbine device. The wind flow relative to the fluid turbine device  100  is shown in dotted lines with arrowheads. Wind flow is divided by the leading edge portion  108  of the fluid turbine device  100 . Wind flow is deflected by the leading edge portion  108  around an external surface of the shroud  106  on the left side as shown in  FIG. 3 , but external to the vertical blade assembly  102 . In this exemplary manner, wind flow is deflected from entering a return path of the fluid turbine device  100  on the side. On a right side of the fluid turbine device, as shown in  FIG. 3 , wind flow is permitted to enter a drive path of the vertical blade assembly  102 , thereby rotating the vertical blade assembly  102  relative to the shroud  106 . 
     By limiting the fluid flow into the return path of the vertical blade assembly  102 , the fluid turbine device  100  may operate with reduced fluid resistance to provide efficient operation of the vertical blade assembly  102 . Additionally, or alternatively, the laminar flow about the leading edge portion  108  of the shroud  106  deflects wind flow about the fluid turbine device  100 , effectively reducing direct wind flow contact (perpendicular to a surface) with fluid turbine device  100  (except for the blades  104  in the drive path). By limiting the direct wind flow contact, wind flow force on the overall fluid turbine device  100  and its support structure is also reduced, while providing efficient use of applied loads for generation of power. 
     As shown in  FIG. 3 , the leading edge portion  108  includes a surface  116  for deflecting a portion of a fluid flow in one direction to inhibit entry into the return path and a surface  117  at an angle relative to the surface  116 , for deflecting a portion of the fluid flow in a different direction towards a drive path of at least a portion of the vertical blade assembly  102 . The surface  116  is angled relative to the surface  117 , at about 61 degrees. Other shapes, sizes and configuration (e.g., angles greater or less than 61 degrees, etc.) of surfaces including a leading edge portion may be employed in other embodiments of a fluid turbine device. In some embodiments, a surface for deflecting fluid towards a drive path may be omitted. 
     It should also be appreciated that different shapes and/or sizes of fluid turbine devices may be employed in other embodiments. Specifically, the ratio of the diameter (of the vertical blade assembly  102 ) to the height of the fluid turbine device  100  is about 1:2. A ratio of height to radius, the radius, and/or the height may be different, potentially based on one or more characteristics of an intended installation site or an environment (such as typical wind speed, densities of wind impediments buildings, trees, etc.), required rotational/electrical output, manufacturing/fabrication, etc. Further, a different number, size , and/or configuration of blades may be included in other vertical blade assembly embodiments to affect fluid flow in a drive path, a return path, and/or fluid exhaust from a fluid turbine device. Additionally, although the fluid turbine device  100  defines an axis perpendicular to ground in the embodiment shown in  FIGS. 1 and 2 , it should be further appreciated that a fluid turbine device may be disposed such that the axis of the fluid turbine device is at a different angle relative to ground, e.g., parallel, non-perpendicular, etc. 
     As shown in the exploded views of  FIGS. 4A-D , the vertical blade assembly  102  includes end plates  118 ,  120  disposed on opposite ends of the multiple blades  104 . The multiple blades  104  are evenly distributed about the central axis  122  of the vertical blade assembly  102 , and substantially at the edge of the end plates  118 ,  120 . Each of the six blades  104  is disposed such that the end points of the blades are collinear to the central axis  122  of the vertical blade assembly  102 . In other embodiments, a different number, size, type, configuration, and/or placement of blades may be employed in a vertical blades assembly. 
     As shown in  FIGS. 4A-D , the end plate  118  includes multiple openings  124  to permit fluid flow from within the compartment  114  defined by the vertical blade assembly  102 . When in use, the vertical blade assembly  102  rotates as a function of the wind flow entering the drive path of the vertical blade assembly  102 . Rotation of the vertical blade assembly  102  may contribute to the formation of a wind vortex within the vertical blade assembly  102 . The wind vortex permits exhaustion of wind flow through one or more of the multiple openings  124  in the end plate  118 . A different number, shape, and/or size of openings may be defined by different fluid turbine device embodiments. In at least one embodiment, a bottom end plate may be omitted. 
     The shroud  106  includes a shroud skirt  126 . The shroud skirt  126  extends slightly above the end plate  118  to assist in formation of the wind vortex within the vertical blade assembly  102 . In this particular embodiment, the shroud skirt  126  provides generally consistent laminar flow below the vertical blade assembly  102  to prevent disturbances in the laminar flow about the fluid turbine device  100  at the vertical blade assembly  102 . A different configuration of a shroud skirt may be included in different shroud embodiments and employed otherwise relative to the vertical blade assembly to reduce turbulence and/or assist laminar flow. 
     Also shown in  FIG. 1 , the fluid turbine device  100  includes a cowling  128  coaxially disposed relative to the vertical blade assembly  102 . The cowling  128  provides a path of low resistance for the wind vortex to be received through the openings  124  defined in the end plate  118 . When the wind vortex exits the vertical blade assembly  102 , the cowling  128  guides the wind vortex out and away from the fluid turbine device  100 , thereby providing an exhaust path for the wind vortex. In this manner, interaction between the exhausted wind vortex and the fluid flow relative to the drive path of the vertical blade assemble  102  may be limited, thereby providing efficient operation of the fluid turbine device  100 . As the wind vortex is exhausted through the multiple openings  124  defined in the end plate  118  and deflected by the cowling  128 , additional wind flow enters the drive path of the vertical blade assembly  102 , with reduced turbulence, to further rotate the vertical blade assembly  102 . 
     With reference to  FIGS. 1-3 , the fluid turbine device  100  is configured such that the vertical blade assembly  102  rotates counter-clockwise ( FIG. 3 ). Alternatively, as shown in  FIG. 5 , a fluid turbine device  200  includes a vertical blade assembly  202  configured to rotate clockwise about a central axis  222 . Further, a cowling is omitted from the fluid turbine device  200 . In this manner, a fluid vortex may be formed within the fluid turbine device  200  and sufficiently exhausted from the fluid turbine device  200  such that guiding the fluid vortex by a cowling may not be necessary for a desired operation of the fluid turbine device. 
     According to another embodiment of the present disclosure,  FIG. 6  illustrates a fluid turbine device  300  including a vertical blade assembly  302  having an end plate  318 . The end plate  318  is disposed adjacent to multiple chambers  330 . Each of the chambers  330  includes a fluid, such as anti-freeze, etc., sealed therein. Each of the chambers  330  are angled such that an end proximate to a central axis  322  of the vertical blade assembly  302  is lower than an end of the chamber distal from the central axis  322 . In this manner, the fluid sealed within the chambers  330  rests substantially at the proximate end—close to the central axis  322 —when the vertical blade assembly  302  is not rotating. Alternatively, when the vertical blade assembly  302  is rotating, the fluid sealed within the chambers  330  moves toward the perimeter of the end plate  318 . In this manner, the vertical blade assembly  302  gains inertia to resist changes in rotation due to minor and/or transient changes in fluid flow relative to the fluid turbine device  300 . On the contrary, when the fluid rests at the proximate end of the chambers  330  (the center axis  322  of vertical blade assembly  302 ), the vertical blade assembly  302  is more susceptible to changes in rotating, thereby providing easier initial rotation of the vertical blade assembly  302  from stop. 
     It should be appreciated that a different type of mass may be included at one or more locations in a fluid turbine device to affect the inertia of the vertical blade assembly when rotating. Further, the masses may be distributed differently—evenly or otherwise—to affect the inertia of a vertical blade assembly. In at least one embodiment, one or more chambers may comprise an end plate of a vertical blade assembly. Additionally, or alternatively, one or more chambers may be included at one or more different locations along a central axis of a vertical blade assembly, or elsewhere in a fluid turbine device, in some embodiments. In one example, chambers may be disposed at a top and/or a middle of a vertical blade assembly. 
     Referring again to  FIGS. 4A-D , the fluid turbine device  100  includes multiple generators  132  enclosed by a generator enclosure  154  and mechanically coupled to the vertical blade assembly  102 . The multiple generators  132  are provided to generate power when the vertical blade assembly  102  is rotated. While the fluid turbine device  100  includes four generators  132 , a different number of generators may be included in different fluid turbine device embodiments. Generators may include any device suitable to convert mechanical energy into electrical energy. 
     In this particular embodiment, the generators  132  are alternators, which may need an electric field applied thereto—energized—prior to generating power. In this manner, each of the generators  132  may be selectively operated. In the particular embodiment shown, the generators  132  are selectively operated based on a rotational speed of the vertical blade assembly  102 . As the speed of the vertical blade assembly  102  increases, the number of generators  132  energized also increases. In this manner, one or more of the multiple generators  132  may be operated close to peak output conditions, while the generators that are un-energized are not contributing to power generation or substantially inhibiting rotation of the vertical blade assembly—efficiency of the energize generators. Further, in various embodiments, rotational speeds coupled to each of multiple generators may be adjusted from one generator to another generator (e.g., via a planetary gear assembly, clutching device, electronic load device, etc.) to match an appropriate rotational speed with one or more characteristics of a particular generator. An exemplary planetary gear assembly  156  is shown in  FIGS. 4A-D . In this particular embodiment, the generators  132  are permanent magnet alternators. In other embodiments, the generators may be other types of alternators, motors, etc., such as an inductance motor. 
     Additionally, or alternatively, in some applications, multiple generators may permit a fluid turbine device to generate at least some power, even if one of the multiple generators is not functional, e.g., damaged, etc. Accordingly, a fluid turbine device having less than all of the generators damaged may thus be partially functional even while waiting for the damaged generators to be repaired. 
     As shown in  FIG. 7 , a fluid turbine device  400  according to another embodiment of the present disclosure includes a shroud  406  and a steering assembly  434  coupled to the shroud  406 . The steering assembly  434  is configured to orient the leading edge portion  408  of the shroud  406  in-line with a direction of fluid flow. The steering assembly  434  includes a rudder connected to the shroud  406 . In the particular embodiment of  FIG. 7 , the steering assembly  434  is sufficiently compact to fit within the footprint of the vertical blade assembly  402  and shroud  406 . In other embodiments, different shapes, sizes, and configurations of rudders, for example, beyond a footprint of a vertical blade assembly and/or shroud, may be employed to orient a shroud relative to a direction of fluid flow. 
     In the embodiment of  FIGS. 8A-B , a fluid turbine assembly  500  includes a steering assembly. The steering assembly includes a fluid flow detector  536  and a motor  538  operably coupled to the fluid flow detector  536 . As shown in  FIG. 8A , the fluid flow detector  536  is disposed at the leading edge portion of the shroud  506 . As shown in  FIG. 8B , the motor  538  is disposed adjacent to a frame member  542  of the shroud  506  to orient the shroud  506  in-line with a direction of fluid flow, as detected by the fluid flow detector  536 . In this particular embodiment, the motor  538  includes a servo motor. Other suitable types of motors, such as stepper motors, etc., and fluid flow detectors may be employed in other embodiments in one or more different positions on or near a shroud or fluid turbine device to orient the shroud in a direction of fluid flow. In some embodiments, a steering mechanism may be configured to orient a leading edge portion of a shroud relative to the direction of the fluid flow to be offset from the direction of fluid flow to compensate for an over-speed condition, such as inclement weather, etc. Orienting of the shroud in this manner may restrict the rotational speed of a vertical blade assembly to an acceptable operating range such that the fluid turbine device is able to operate during the over-speed condition and continue to generate power, rather than shutting down. 
     According to another exemplary embodiment of the present disclosure, a shroud  606  for a fluid turbine device is shown in  FIG. 9 . The shroud  606  includes an apertured surface  640  and a leading edge portion  608 . The shroud&#39;s leading edge portion  608  has a surface  616  for deflecting fluid from a return path of multiple blades of a vertical blade assembly and a surface  617  for deflecting fluid flow into a drive path of the multiple blades. The surfaces  616 ,  617  are angled relative to one another (e.g., at an angle of about 60 degrees, etc.). The shroud  606  also includes a shroud skirt  626  and a frame member  642  for supporting the shroud skirt  626  and/or receiving a central axis of a vertical blade assembly. In the particular embodiment, the frame member  642  includes spoke segments  644  having reduced surface area in the direction of an axis to be received by the frame member  642  to limit interference with fluid flow relative to a vertical blade assembly. 
     As shown, the apertured surface  640  includes multiple staggered rows of openings  612 . In other embodiments, such as shown in  FIG. 2 , a shroud may include elongate openings. It should be appreciated that a different pattern (e.g., stagger or un-staggered, etc.) size, shape, and/or number of openings may be included in different shroud embodiments. In at least some embodiments, a pattern of openings defined by an apertured surface may be dependent on a desired fluid flow between the two sides of the apertured surface or an expected pressure differential generator on the two sides of the apertured surface. Additionally, or alternatively, other factors, such as environmental characteristics, etc., may be considered. 
     One or more fluid turbine devices as disclosed herein may be included in an electrical system in some embodiments. In one example embodiment, shown in  FIG. 10 , an electrical system may include a grid  746  and multiple fluid turbine devices  700  electrically coupled to the grid  746 . The multiple fluid turbine devices  700  provide power to the grid  746 , which may be electrically connected to power one or more electrical devices. The grid  746  may be a grid private to the multiple turbine devices  700  or a public utility grid. In at least one embodiment, multiple fluid turbine devices are coupled to a private grid that is coupled to a public utility grid at a junction. A gateway device disposed at the junction opens/closes electrical continuity based on potential power generated by the fluid turbine devices. In another embodiment, as shown in  FIG. 11 , an electrical system may include an energy storage device (e.g., one or more batteries, capacitors, etc.)  848  and a fluid turbine device  800  electrically coupled to the battery  848 . The battery  848  may be employed to store un-used power generated by the fluid turbine device  800 . In still other embodiments, an electrical system may be a different combination of grids (public or private), storage devices, and fluid turbine devices. 
     According to another embodiment, a wind turbine device is illustrated in  FIG. 12 . The wind turbine device  900  is coupled to a support structure  952  of a billboard assembly  950 . The billboard assembly  950  may include lights and/or one or more displays (not shown), which may be powered by the wind turbine device  900 . The billboard assembly  950  may be coupled to a grid so that power generated by the wind turbine device  900  (but not used by the lights and/or displays) may be supplied to other electrical devices and/or batteries coupled to the grid. The billboard assembly  950  may or may not include one or more batteries. It should be appreciated that a wind turbine device may be coupled to one or more other components of a billboard assembly, as long as the wind turbine device  900  is exposed (at least part of the time) to fluid flow.  FIG. 12  illustrates but one example environment in which aspects of the present disclosure may be used. Alternative uses and environments are also possible for an embodiment of a fluid turbine device disclosed herein, including uses and environments in which the blades are caused to rotate by either a flow of gas (e.g., air, etc.) or liquid (e.g., water, etc.). 
     According to another embodiment of the present disclosure, a method related to the operation of a fluid turbine device having a vertical blade assembly is disclosed. The method includes deflecting a portion of a fluid flow from a return path of the vertical blade assembly, while permitting another portion of the fluid flow to enter a drive path of the vertical blade assembly. 
     The fluid turbine device may include a shroud disposed at least partially about the vertical blade assembly to deflect the portion of the fluid flow from the return path. The method may further include orientating the shroud relative to a direction of the fluid flow to adjust the portions of fluid flow deflected from the return path and permitted into the drive path. The shroud may be oriented based on a rotational speed of the vertical blade assembly, a temperature of one or more generators mechanically coupled to the vertical blade assembly, etc. 
       FIG. 13  illustrates a fluid turbine device  1000  according to another example embodiment. The fluid turbine device  1000  includes a vertical blade assembly  1002  and a shroud  1004  rotatably coupled to the vertical blade assembly  1002 . The vertical blade assembly  1002  includes six blades  1006 A-F. This illustration also shows efficient exhaust paths including a vortex  1008 . In this particular embodiment, the vertical blade assembly  1002  is permitted to rotate at a threshold rotational speed sufficient to form the vortex  1008 . The rotational speed of the vertical blade assembly  1002  is additionally restricted above the threshold rotational speed, so that the fluid flow against the blades  1006  generates increased force (as compared to an unrestricted rotational speed). Restricting the rotation speed (above the threshold rotation speed) further reduces introduction of turbulence into the fluid flow, which is better for subsequent or downstream fluid turbine devices. For example, a threshold rotational speed to generate a vortex may include about 50 rpms, and the vertical blade assembly  1002  may be restricted to a range of about 60-200 rpms to ensure formation of the vortex  1008 , but restrict the rotational velocity and reduce turbulence. 
       FIG. 14  is a plan view of an exemplary embodiment of a fluid turbine device  1100  and illustrating generator gearing for rotational speed control. As shown in  FIG. 14 , the fluid turbine device  1100  includes a vertical blade assembly  1102  and four generator gears  1104 A-D (coupled to generators  1106 A-D) disposed about another gear  1108  coupled to the vertical blade assembly  1102 . In this example, a gearing ratio of 50:1 is illustrated. Alternative embodiments may include different configurations such as configurations that include more or less gears. Also, a wide range of gearing ratios may be used in other embodiments. For example, gearing ratios ranging from 2:1 to 200:1, or any of the discrete ratios therebetween, may be used in other exemplary embodiments. In another example embodiment, a gearing ratio of 4:1 is used. In a further example embodiment, a gear ratio of 25:1 is used. In an additional example embodiment a gearing ratio of 100:1 is used. 
       FIG. 15  illustrates a fluid turbine device  1200  according to another example embodiment of the present disclosure. The fluid turbine device includes a vertical blade assembly  1202  and a shroud  1204 . As shown the shroud includes a leading edge  1206 , which is offset from the direction of the fluid flow  1208 , or in this example, wind. The fluid turbine device  1200  includes a motor  1209  coupled to the shroud  1204  to orient the shroud  1204  relative to the direction of the fluid flow  1208 . In this particular embodiment, the motor  1209  (e.g., a stepper motor, etc.) orients the leading edge  1206  of the shroud  1204  into the direction of the fluid flow  1208 , as shown in  FIG. 16 . As should be apparent, the shroud may be oriented relative to the direction of the fluid flow by other devices, mechanically and/or electrically. For example, as explained with respect to  FIG. 7 , a rudder  434  may be employed.  FIG. 17  illustrates that the shroud  1204  may be oriented relative to the direction of the fluid flow, via the motor  1209  and control  1210 , in either the counter-clockwise direction ( FIG. 17A ) or the clockwise direction ( FIG. 17B ). 
     The shroud may be oriented relative to the direction of fluid flow for various reasons, including a rotational speed of the vertical blade assembly, a temperature of one or more generators mechanically coupled to the vertical blade assembly, etc. In this example, the leading edge  1206  was oriented to increase the portion of the fluid flow into the drive path of the vertical blade assembly  1202 . In other embodiments, the shroud may be oriented to reduce the portion of fluid flow entering the drive path. For example, the shroud may be oriented to reduce the portion of fluid flow entering the drive path to control the rotational speed of the vertical blade assembly relative to a predetermined rotational speed. Additionally or alternatively, the shroud may be oriented relative to the direction of the fluid flow to control the rotational speed when all generators coupled to the vertical blade assembly are activate, or when less than all generators are active. 
     Referring to  FIG. 15 , the fluid turbine device  1200  includes a control  1210  and a sensing device  1212 . The control  1210  is operably coupled to the sensing device  1212  and configured to activate the generators based on the sensed operating characteristic of the fluid turbine device  1200 . In this particular embodiment, as explained above, the operating characteristic is a rotational speed of the vertical blade assembly and the sensing device  1212  is a speed sensor positioned to determine the rotational speed of the vertical blade assembly  1202 . The control  1210  is configured to activate said generator when the sensed rotational speed of the vertical blade assembly  1202  exceeds a predetermined speed, such as 50 rpms, etc. 
     As should be apparent other operating characteristics may be sensed, and the sensing device may be of a different type, to activate one or more generators included in another fluid turbine device embodiment. Other operating characteristics may include, for example, the temperature of one or more generators, the temperature of one or more bearings, the temperature of one or more gears or gear boxes, etc. 
     Further, in the embodiment of  FIG. 15 , each of the four generators includes a shaft (not shown) coupled to gears  1214 A-D. Each of the gears is mechanically coupled to a gear  1216  coupled to and rotatable with the vertical blade assembly  1202 . The gears  1214 A-D are configured such that one rotation of the vertical blade assembly  1202  causes multiple rotations of the shaft. Specifically, in this embodiment, for each rotation of the vertical blade assembly  1202 , each shaft of each generator rotates 50 times. As should be apparent, a different gear having different configurations, as well as a different number of generators, may be included in other embodiments. For example, the gearing ratio may include the ranges disclosed above. 
     In another example, when all of the generators included in a fluid turbine device are active, a control may receive an input from a sensor indicating the temperature of one or more generators included in the FTD. In this example, the control may be configured to orient a leading edge of the shroud in a direction offset from the direction of the fluid flow to adjust the portions of the fluid flow when each of the multiple generators is activated and the temperature of one or more of the generators exceeds a pre-determined value. Additionally or alternatively, the control  1210  may be configured to orient the leading edge  1206  of the shroud  1204  in a direction offset from the direction of the fluid flow to adjust the portions of the fluid flow when each of the multiple generators is activated and the rotational speed exceeds the predetermined speed, such as 200 rpms or another rotational velocity above 200 rpms, etc. It should be appreciated that the shroud of the fluid turbine device may be orientated based on one or more operating characteristics of the fluid turbine device to protect the fluid turbine device from damage, such as overheating, exceeding component maximums, etc., and to regulate generation of power, preferable to an optimal or substantially optimal performance. 
     Further, the generators included in the fluid turbine device  1200  are evenly distributed above a central axis of the fluid turbine device  1200 . Other configurations, balances and un-balanced, may be employed in other fluid turbine device embodiments. For example, a fluid turbine device may include one, two, five, six, seven, or more generators, etc. 
     When a fluid turbine device includes multiple generators, the generators may be activated to regulate the rotational speed of the vertical blade assembly. In the example embodiment of  FIG. 15 , the control  1210  is configured to activate one of the multiple generators whenever the sensed rotational speed exceeds a predetermined speed, until each of the multiple generators are activated. Generators may be activated by mechanically coupling the generator to a vertical blade assembly, or in this particular embodiment, by energizing the generator, etc. Further, in this example, the control  1210  is configured to orient the leading edge  1206  of the shroud  1204  in a direction offset from the direction of the fluid flow  1208  to adjust the portions of the fluid flow when each of the multiple generators is activated and the rotational speed exceeds the predetermined speed. 
     In some example embodiments, two or more fluid turbine devices may be collectively coupled on one or more platforms, structures, or other mounting apparatus. Additionally, these fluid turbine devices can operate simultaneously on a platform, structure, or other mounting apparatus. The platforms, structures, and mounting apparatus can be stacked such that each platform, structure, or mounting apparatus are fixed or coupled to each other. Many variations of stacking, coupling, ganging, number of fluid turbine devices, and combinations thereof may be utilized. Additionally, the platforms, structures, or mounting apparatus can be comprised of many shapes, sizes, and dimensions. And, such platforms, structures, or mounting apparatus can be combined to comprise multiple platforms, structures or mounting apparatus. Exemplary fluid turbine devices disclosed herein are designed to be modular enough for installation in a variety of existing structures from commercial to residential, while addressing the noise syndrome issues associated with large commercial wind turbines. 
       FIG. 18  illustrates an exemplary embodiment of a wind farm  1300  that includes two fluid turbine devices  1302  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus. The fluid turbine devices  1302  are arranged linearly and side-by-side in this example, which allows both fluid turbine devices  1302  to be located in the fluid flow, such as a wind path. 
       FIG. 19  illustrates an exemplary embodiment of a wind farm  1400  that includes four fluid turbine devices  1402  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus  1404 . The four fluid turbine devices  1402  are linearly arranged and side-by-side in this example. This example allows all four fluid turbine devices  1402  to be located in the wind path. 
       FIG. 20  illustrates an exemplary embodiment of a wind farm  1500  that includes seven fluid turbine devices  1502  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus  1504 . In this example, three fluid turbine devices  1502  are disposed above the four lower fluid turbine devices  1502 . While this example only illustrates two layers of platforms, structures, or other mounting apparatus fixed or coupled to each other, other embodiments may include any number of layers, different arrangements, shapes, sizes, dimensions, etc. of the platforms, structures, or other mounting apparatus. There can be many variations of stacking, coupling, number of fluid turbine devices and combinations of the aforementioned. For example,  FIG. 21  illustrates additional exemplary embodiment of a wind farm  1600  that includes fluid turbine devices  1602  in an example stacked arrangement, supported by a structure  1604 .  FIG. 22  illustrates another exemplary embodiment of a wind farm  1700  that includes fluid turbine devices  1702  in an example stacked arrangement, supported by a structure  1704 . In other examples, fluid turbine devices may form an irregular pattern, omitting fluid turbine that may have reduced wind flow thereto. For example, a tree, building, or other wind interruption, etc. may provide reasons to omit a fluid turbine device for a pattern of rows, stacks, and columns, etc. 
       FIG. 23  illustrates an exemplary embodiment of a wind farm  1800  that includes eight fluid turbine devices  1802  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus  1804 . In this example, seven fluid turbine devices  1802  are disposed about a middle or center fluid turbine device  1802  and arranged in a heptagonal configuration. A wide range of other configurations are also possible for this ganging or coupling aspect of the fluid turbine devices  1802  including triangular, octagonal, circular, rectangular, or other geometric patterns, etc. For example,  FIG. 24  illustrates another exemplary embodiment of a wind farm  1900  that includes four fluid turbine devices  1902  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus  1904 . In this example, three fluid turbine devices  1902  are disposed about a middle or center fluid turbine device  1902  and arranged in a triangular configuration. Yet another exemplary embodiment of a wind farm  2000  is illustrated in  FIG. 25 , which includes 12 fluid turbine devices  2002  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus  2004 . In this example, the fluid turbine devices  2002  are arranged in a rectangular array that includes 3 rows and four columns. 
     In some exemplary embodiments, there may be multiple platforms, structures, or mounting apparatus that are coupled together for supporting one or more fluid turbine devices. For example, multiple pillars may be coupled together. 
       FIG. 26  illustrates an exemplary embodiment of a wind farm  2100  in which a plurality of fluid turbine devices  2102  are supported by a framework or structure  2104 . The structure  2104  includes pillars or vertical support members  2106  have an airfoil configured (e.g., designed, attached, located, etc.) to direct laminar flow through the structure  2104  thus reducing turbulence. By way of example,  FIG. 27  illustrates an example of a vertical support member  2106  having an airfoil that may be used in the structure  2104  shown in  FIG. 26 . 
       FIGS. 29A-B  illustrates a fluid turbine device  2300  according to another example embodiment of the present disclosure. The fluid turbine device  2300  includes a vertical blade assembly  2302  and a shroud  2304  disposed at least partially about the vertical blade assembly  2302 . The shroud  2304  includes a shroud skirt  2306  at the top and a shroud skirt  2308  at the bottom. The shroud skirts  2306 ,  2308  are disposed to inhibit the ingress of debris (e.g., dust, etc.) into the vertical blade assembly  2302  and/or the fluid turbine device  2300 . In this particular embodiment, the shroud skirt  2306  extends downward (e.g., less than 1 inch, 1 inch, 2 inches, 3 inches or more, etc.) to cover a top portion of the vertical blade assembly  2302 , and the shroud skirt  2308  extends upward (e.g., less than 1 inch, 1 inch, 2 inches, 3 inches or more, etc.) to cover a bottom portion of the vertical blade assembly  2302 . Alternatively, the shroud skirts may extend substantially level with the end plates of the vertical blade assembly  2302  to permit fluid access to substantially the entire surface of the blades  23  of the vertical blade assembly  2302 . As shown, the shroud  2304  includes an end plate  2310  coupled to the shroud skirt  2306 , which extends even with the end plate  2310 . 
     As shown in  FIGS. 28A-B , the shroud skirt  2306  includes a leading end portion  2312  and a blade assembly portion  2314 . The blade assembly portion  2314  is positioned circumferentially about at least a portion of the vertical blade assembly  2302 . The leading edge portion  2312  tangentially couples to the blade assembly portion  2314 . It should be appreciated that in other embodiments, one or more shroud skirts may be omitted or include a different configuration (shape, size, orientation, position, etc.). 
     Yet another exemplary embodiment of a wind farm  2200  is illustrated in  FIG. 28 , which includes seven fluid turbine devices  2202  coupled and/or ganged together, for operating collectively and/or simultaneously on a platform, structure, or other mounting apparatus  2204 , having vertical support members  2206 . In this example, the fluid turbine devices  2202  are arranged in a hexagon array with one fluid turbine device  2202  in the middle. 
     Additional aspects of the present disclosure provide methods relating to the operation of a fluid turbine device. One such method includes deflecting a first portion of a fluid flow from a return path of a vertical blade assembly, while permitting a second portion of the fluid flow to enter a drive path of the vertical blade assembly. In one example embodiment, the fluid turbine device includes a shroud disposed at least partially about the vertical blade assembly to deflect the first portion of the fluid flow. Another example method includes operating the fluid turbine device by slowing its vertical blade assembly to increase applied pressure to increase pressure to the drive path where the fluid turbine device&#39;s laminar flow is achieved thereby reducing the propensity for turbulence. 
     A further example method includes tuning or orienting the shroud to achieve laminar flow. Specifically, the shroud may be tuned or oriented relative to a direction of fluid flow to adjust the portion of air deflected from the return path and the portion of fluid flow permitted to enter the drive path. The shroud may be oriented based on one or more of a rotational speed of the vertical blade assembly, a temperature of one or more generators mechanically coupled to the vertical blade assembly, etc. Yet another method may include regulating the rotational speed of the vertical blade assembly. The rotational speed may be regulated by orienting the shroud, activating one or more generators, mechanically restricting rotation of the vertical blade assembly, etc. In one example method, regulating the rotational speed includes activating at least one of multiple generators mechanically coupled to the vertical blade assembly. Further, in the example method, activating one of the multiple generators may include activating one of the multiple generators when the rotational speed of the vertical blade assembly exceeds a predetermined speed, until each of the multiple generators is activated. Alternatively, or additionally, the example method may also include deactivating at least one of the multiple generators when the rotational speed of the vertical blade assembly falls below a predetermined speed. 
     Another example embodiment includes a method related to a fluid turbine device. The fluid turbine device includes a shroud and a vertical blade assembly defining a central axis and having multiple blades disposed about the central axis. The shroud is disposed at least partially about the vertical blade assembly. The vertical blade assembly is rotatable about the central axis in response to a fluid flow and mechanically coupled to a generator. The example method includes orienting the shroud relative to the fluid flow to deflect a first portion of the fluid flow from a return path of the vertical blade assembly and to permit a second portion of the fluid flow to enter a drive path of the vertical blade assembly and activating the generator, based on an operating characteristic of the fluid turbine device, to regulate the rotational speed of the vertical blade assembly. 
     Additionally, orienting the shroud includes orienting the shroud in the direction of the fluid flow. Further, the operating characteristic is rotational speed of the vertical blade assembly in some example embodiments. Additionally, or alternatively, the example method may include activating the one of multiple generators whenever the rotational speed exceeds a predetermined speed, until each of the multiple generators is activated. Additionally, orienting the shroud may include, for example, orienting the shroud in a direction offset from the direction of the fluid flow to adjust the portions of the fluid flow when each of the multiple generators is activated and the rotational speed exceeds the predetermined speed. In some example methods, activating a generator includes applying power to said generator. Additionally, or alternatively, activating a generator may include mechanically coupling the generator to the vertical blade assembly, whereby rotation of the vertical blade assembly causes rotation of a shaft extending from the generator. 
     Yet another method includes the technique of leveraging multiple devices on a shared platform, structure, or other mounting apparatus where said shared space can be stacked. Additionally, there can be a plurality of platforms, structures, or other mounting apparatus. 
     A method may also include generating a pressure differential for exhausting fluid from the return path and through a shroud assembly coupled to the vertical blade assembly. Specifically, in one example, the fluid may be exhausted through one or more apertures in the shroud. Additionally, or alternatively, a method may include forming a fluid vortex within the fluid turbine device and exhausting the fluid vortex through an end plate of the vertical blade assembly. In some embodiments, permitting a portion of the fluid flow to enter a drive path of the vertical blade assembly may include deflecting fluid flow into the drive path of the vertical blade assembly. 
     A method may include selectively activating a plurality of generators based on a rotational speed of the vertical blade assembly. Additionally, or alternatively, a method may include redistributing mass from an interior position relative to the vertical blade assembly toward a perimeter position of the vertical blade assembly to limit the affect of fluid flow fluctuations. 
     In another exemplary method relating to the operation of a fluid turbine device, the velocity or rotational speed of the turbine is slowed to increase the pressure applied to the drive path where the device&#39;s velocity is equal to or greater than the point where laminar flow is achieved, thus reducing the propensity for turbulence. The reduced velocity is realized by manipulation of load demands applied to the electrical generation system. 
     In a further exemplary method relating to the operation of a fluid turbine device, the velocity or rotational speed of the fluid turbine device is manipulated to either increase, decrease or keep the pressure applied to the drive path at optimal efficiency (or at least a good or improved efficiency) by tuning or orienting the shroud in a bidirectional manner when maximum capacity is reached; by tuning or orienting the shroud to more directly direct fluid to the drive path when peak capacity is not reached; and by keeping the shroud in the optimal position when at peak capacity. 
     In one or more exemplary methods, the fluid turbine device may be operating such that the velocity or rotational speed of the fluid turbine device is slowed to increase the pressure applied to the drive path. By way of background, when a stationary object is impacted by force, it has a certain resistance. When the same stationary object moves into the force, greater pressure is achieved. But moving with the force reduces pressure. Thus, a maximum energy exchange may be achieved when at a standstill or moving into the force. 
     The fluid turbine device&#39;s velocity or rotational speed may be equal to or greater than the point where laminar flow is achieved, thus reducing the propensity for turbulence. The velocity or rotational speed of the fluid turbine device may be realized by manipulation of load demands applied to the electrical generation system. A wide range of gearing ratios may be used to transfer loads from the fluid turbine device to an electric generation system. By way of example, gearing ratios ranging from 1:1 to 50:1 (or more) may be used in exemplary embodiments of the present disclosure. In an example embodiment, a gearing ratio of 4:1 is used. In another example embodiment, a gear ratio of 25:1 is used. In still a further example embodiment a gearing ratio of 100:1 is used. It should be appreciated that in various embodiments, a sufficiently high gear ratio is provided to reduce the velocity or rotational speed of the vertical blade assembly, in order to increase the pressure applied to each blade. As should be apparent in such embodiments, any gear ratio may be selected, which is sufficient to reduce velocity or rotational speed of the vertical blade assembly, thereby providing increased pressure and thus increase the harvest potential form the fluid turbine device. 
     The shroud may be oriented or tuned when the electrical demand loads have been completely exhausted and/or when at maximum output, in order to avoid or mitigate damage. For example, the shroud is tuned or oriented when the fluid turbine device has achieved capacity by blocking incoming forces so that the fluid turbine device is able to continue load generation at peak capacity. The tuning or orienting of the shroud may occur when fluid turbine device is not achieving peak capacity so that the shroud further directs more force into the drive path. The tuning or orienting of the shroud can occur in a bidirectional manner. 
     In some applications practicing one or more of the methods disclosed herein, a fluid turbine device may provide efficient fluid flow path through and/or about the fluid turbine device, thereby reducing fluid flow turbulence of a vertical blade assembly and providing an efficient fluid turbine device. Additionally or alternatively, in some applications, a fluid turbine device according to the present disclosure may provide reduced loads on the fluid turbine device, and as a result less load on a structure supporting the fluid turbine device. In this manner, fluid turbine devices according to the present disclosure may be coupled to structures understood by those skilled in the art to be insufficient to harness fluid flow potential. 
     Various exemplary embodiments may include one or more vertical axis wind turbines configured with one or more of the following features, such as a configuration that allows the force of the wind to impact the turbine blade in a perpendicular manner. A shroud is provided for protecting the return side of the turbine. The shroud creates an “airfoil” effect and area of reduced air pressure. This lower pressure area reduces turbulence and air compression within the shroud. The shroud is independent to the turbine blade assembly. Control of the shroud may occur via a rudder or electro-mechanical means supported by a wind direction sensor. These components determine and influence rotation and inherent spin direction of the vortex generated within the turbine. Open circular ports may be located on the lower end plate of the turbine, which will increase laminar flow creating a vortex or “tornado” effect. The additional wind velocity in the center of the turbine will increase the efficiency of the unit. An angular leading edge nose will slightly compress the air at the initial point of contact thus compounding the forces applied. A rudder steering mechanism will constrain the deflector shroud to face into the wind directly. To attain maximum or improved efficiency at various levels of wind forces, an array of small generators may be positioned with a planetary gearing arrangement. Monitored by a tachometer and excited individually, the turbine may be operable to make full use of all wind speeds. The planetary gear configuration will increase the ratio of the generator revolutions per minute to that of the turbine. An undercarriage support structure may be provided with tubes orientated slightly upwards from the center out. Fluid, internal to these tubes will be centrifugally forced outwards during rotation thus increasing the potential and minimizing or reducing the impact of generators turning on sequentially. The concept of multiple small generating units may allow for reductions in cost of fabrication and increase the overall efficiency in all or various wind levels. Repair and maintenance may be conducted without the assistance of large cranes. The modular design may help ensure peak operating efficiencies by reducing the potential of full system down time. Isolation of an individual turbine for repair or maintenance, while other generators on the tower continue to operate, will keep the system at maximum potential. 
     Various exemplary embodiments may provide a vertical axis wind turbine that has a compact design, which permits installation in previously inaccessible wind corridors and/or installation on tall buildings in metropolitan areas, billboards in suburban settings and water towers in rural settings. An exemplary embodiment of a vertical axis wind turbine disclosed herein may provide one or more of the following advantages: modular design, varying size configurations, and/or reduced and/or easier maintenance. 
     In various exemplary embodiments, a wind farm is comprised of a plurality of turbine devices disclosed herein, wind farm may be installed on top of large buildings in urban settings in addition to a multitude of other configurations in urban, suburban and rural settings. In this wind farm, the turbine devices may be connected to maximize or increase the energy harvest potential while providing advantages such as scalability, low wind speed operation, reduced maintenance, nearly silent operation, small foot print, fits in most freight elevators, and/or suitable for LEED building initiative. 
     In various exemplary embodiments, a large wind farm is comprised of a plurality of turbine devices disclosed herein, wind farm may be installed in large wind farm settings in rural and urban environments alike. The scope of installation is dependent on various factors, but generally may be scaled according to the size of available space for installation. In various wind farm embodiments, maintenance and repair can be performed on a single turbine device without having to take or shut down the entire wind farm. Other advantages may include operating efficiently in high wind speeds, generation starts in low wind speeds, reduced maintenance required, lower maintenance cost, and/or nearly silent operation. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific systems, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, surfaces, portions and/or sections, these elements, components, regions, surfaces, portions and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, surface, portion or section from another region, surface, portion or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, surface, portion or section discussed below could be termed a second element, component, region, surface, portion or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The disclosure herein of particular values and particular ranges of values for given parameters are not exclusive of other values and ranges of values that may be useful in one or more of the examples disclosed herein. Moreover, it is envisioned that any two particular values for a specific parameter stated herein may define the endpoints of a range of values that may be suitable for the given parameter. The disclosure of a first value and a second value for a given parameter can be interpreted as disclosing that any value between the first and second values could also be employed for the given parameter. Similarly, it is envisioned that disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping or distinct) subsume all possible combination of ranges for the value that might be claimed using endpoints of the disclosed ranges. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.