Patent Publication Number: US-11047360-B1

Title: Methods, systems, and devices to optimize a fluid harvester

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Benefit of U.S. Provisional Patent Application Ser. No. 65/582,482, filed Nov. 7, 2017, is hereby claimed and the disclosure incorporated herein by reference. 
    
    
     STATEMENT OF GOVERNMENTAL INTEREST 
     This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The U.S. Government has certain rights in the invention. 
    
    
     BACKGROUND 
     Conventionally, systems used to harvest wind energy use large masses of machinery high up in the air on tall towers. The machinery generally includes large rotor blades and a connected generator configured to generate electricity as the rotor blades rotate in the wind. The systems must be high up in the air and pivotable with the direction of the wind to efficiently use the rotor blades. Positioning the machinery on the top of the tower adds significant weight to the top of the system and imposes high materials usage in the machinery, tower, and tower foundation. Additionally, the large rotors can be fragile systems, which need to be made from high performance composites. Further, maintenance of the system is difficult as it has to be done high up in the air. These types of problems can become more significant when turbines are installed close to population centers and/or directly on buildings. Similarly, systems used to harvest water energy use large masses of rotating machinery underwater. Because the machinery is in an environment that is not generally easily accessible maintenance of the parts can be difficult. Additionally, the environment can be corrosive to the machinery requiring more frequent maintenance. 
     SUMMARY 
     The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims. 
     In an exemplary embodiment, provided is an apparatus for energy extraction from fluid flow. The apparatus includes a channel, an assembly, and an energy extraction device at least partially located in the channel. The assembly includes a plenum and the channel includes an inlet and an outlet that is in fluid communication with the plenum to allow flow therethrough. The assembly is configured to create a pressure differential between the plenum and the inlet of the channel. The pressure differential causes fluid flow from the inlet of the channel to the plenum. The energy extraction device is configured to extract energy from this fluid flow. 
     The assembly further includes an aperture extending from an exterior surface of the assembly to the plenum to allow flow therethrough. As such, a fluid flow path can be established from the inlet to the plenum and further to the exterior environment via the aperture. The apparatus additionally includes a control system configured to modify the pressure differential to control the fluid flow between the inlet of the channel and the plenum based on a characteristic of an environment of the assembly. 
     A method of extracting energy from fluid flow includes the step of generating fluid flow through a channel. An inlet of the channel is exposed to an external environment and an outlet of the channel is in fluid communication with a plenum of an assembly. The method further includes generating energy based upon the fluid flow. The energy can include at least one of electrical energy, mechanical energy, or pneumatic energy. The method yet further includes modifying a characteristic of the assembly to modify a velocity of fluid in the fluid flow. 
     Further, in accordance with various aspects, provided is an apparatus for energy extraction from fluid flow. The apparatus may include means for causing fluid flow between an inlet of a channel and a plenum fluidly connected to an outlet of the channel. The apparatus may further include means for extracting energy from the fluid flow. The apparatus may yet further include means for modifying the fluid flow based on a characteristic of an exterior environment. 
     The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an exemplary energy extraction apparatus. 
         FIG. 2  illustrates another exemplary energy extraction apparatus. 
         FIG. 3  illustrates yet another exemplary energy extraction apparatus. 
         FIG. 4  illustrates a further exemplary energy extraction apparatus. 
         FIG. 5  illustrates a yet further exemplary energy extraction apparatus. 
         FIG. 6  illustrates an exemplary assembly. 
         FIG. 7  illustrates another exemplary assembly 
         FIGS. 8A and 8B  illustrate yet another exemplary assembly. 
         FIGS. 9A-9C  illustrate exemplary inserts with differing aperture arrangements. 
         FIG. 10  illustrates another exemplary energy extraction apparatus. 
         FIG. 11  illustrates yet another exemplary energy extraction apparatus. 
         FIG. 12  illustrates an exemplary adjustment system for an energy extraction apparatus. 
         FIG. 13  illustrates another exemplary energy extraction apparatus. 
         FIG. 14  illustrates yet another exemplary energy extraction apparatus. 
         FIG. 15  illustrates a further exemplary energy extraction apparatus. 
         FIG. 16  illustrates a yet further exemplary energy extraction apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Various technologies pertaining to extracting energy from fluid flow are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. 
     In reference to the disclosure herein, for purposes of convenience and clarity only, directional terms, such as, top, bottom, left, right, up, down, upper, lower, over, above, below, beneath, rear, and front, may be used. Such directional terms should not be construed to limit the scope of the features described herein in any manner. It is to be understood that embodiments presented herein are by way of example and not by way of limitation. The intent of the following detailed description, although discussing exemplary embodiments, is to be construed to cover all modifications, alternatives, and equivalents of the embodiments as may fall within the spirit and scope of the features described herein. 
     Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form. Additionally, as used herein, the term “exemplary” is intended to mean serving as an illustration or example of something and is not intended to indicate a preference. 
     Disclosed is an apparatus for using fluid flow to generate electrical power. The disclosed apparatus can be placed in a fluid flow stream and can use a pressure differential to “pull” fluid through an energy extraction device to generate the electrical power. The apparatus can “pull” the fluid from an inlet and discharge it into the fluid flow stream. The apparatus can modify the pressure differential based on a received input to control the amount of fluid being “pulled” and/or electricity being generated. 
     Turning to  FIG. 1 , illustrated is one embodiment of an apparatus  100  for energy extraction from fluid flow. The fluid can include gas, liquid, or the like. The apparatus  100  includes an assembly  102 , a channel  104 , an energy extraction device  106 , and a control system, illustrated schematically as  108 . The channel  104  and the assembly  102  may be in fluid communication to allow fluid flow therethrough. Broadly, the apparatus  100  can be configured to cause fluid flow along a fluid path from the channel  104  to the assembly  102  and further to an exterior environment as will be described in detail below. In one embodiment, at least a portion of the energy extraction device  106  is located along the fluid flow and may be configured to extract energy based on the fluid flow. 
     The channel  104  can include an inlet  110  and an opposing outlet  112  and can be configured to allow flow therethrough. In an embodiment, shown in  FIG. 1 , the channel  104  is substantially a hollow cylindrical tube with a circular cross-section. The channel  104  may take any shape consistent with allowing flow therethrough. For example, the cross-section of the exterior of the channel  104  may be oval, square, rectangular, triangular, or the like. The interior of the channel  104  may have a similar shape as the exterior or may vary. Additionally, although illustrated in  FIG. 1  as a single tube, the channel  104  may comprise a network of interconnected tubes in fluid communication. 
     The assembly  102  can include a body  114  formed by at least two opposing sides. In an embodiment, shown in  FIG. 1 , the body  114  comprises two curved sides that connect at two opposing ends to form an airfoil. The airfoil includes a leading edge, an opposing trailing edge, and two curving sides extending therebetween. While the body  114  is described as having the shape illustrated in  FIG. 1 , other shapes are also contemplated. For instance, the body  114  can have a specific shape depending on the environment the assembly  102  is placed in (e.g. aerodynamic shape for an atmospheric environment, hydrodynamic shape for an aquatic environment, etc.). Further, the embodiment of the apparatus  100  illustrated in  FIG. 1  includes one assembly  102  attached to the channel  104 , however the apparatus  100  can include any number of assemblies attached to the same channel  104  or differing channels. 
     The body  114  may include an exterior surface and a plenum  116  that is at least partially enclosed by the exterior surface.  FIG. 1  shows the plenum  116  comprising the entire interior of the body  114 , however the plenum  116  may have any suitable shape. 
     The body  114  may further include a fluid pathway  118  to allow fluid communication between the plenum  116  and the outlet  112  of the channel  104 . The body  114  may yet further include an aperture  120  that extends from the exterior surface of the body  114  to the plenum  116  to allow fluid flow between the plenum  116  and an environment outside the apparatus  100 . In an embodiment, shown in  FIG. 1 , the body  114  can include a plurality of apertures  120 , however any number of apertures  120  greater than zero is hereby contemplated. In the illustrated embodiment, shown in  FIG. 1 , the plurality of apertures  120  are arranged longitudinally along the body  114 , although other arrangements are contemplated. 
     The apparatus  100  may be configured to use fluid dynamics to generate flow through the aperture  120  by generating a pressure differential between the plenum  116  and the outside environment. To generate this pressure differential, the apparatus  100  may be configured to deflect oncoming fluid in the outside environment (e.g. wind), represented by arrow “X”, along the body  114 . The deflection can be caused by at least one of an angle of the body  114  with respect to a direction of the oncoming fluid X flow (e.g. angle of attack), a shape of the body  114 , or the like. 
     The deflection of the oncoming fluid X can result in both a pressure difference and/or an oncoming fluid X velocity difference between the two opposing sides of the body  114 . A first side of the body  114  acts as a suction surface and have a lower average pressure and a higher average velocity than an opposing second side acting as a pressure surface having a higher average pressure and a lower average velocity. 
     In addition to being lower than the average pressure of the pressure side, the average pressure of the suction surface can be lower than the average pressure inside the plenum  116 . Where the plenum  116  and the outside environment at the suction surface are in fluid communication, for example by way of the aperture  120 , the difference in average pressure can cause fluid flow, represented by arrow “Y”, from the plenum  116  to the outside environment at the suction surface. 
     This fluid flow Y out of the plenum  116  into the outside environment can create a pressure differential between the plenum  116  and the inlet  110  of the channel  104 . Where the average pressure of the plenum  116  is lower than the average pressure at the inlet  110 , the pressure differential can generate fluid flow, represented by arrow “Z”, from the inlet  110  of the of channel  104  toward the plenum  116 . Generally, the pressure differential can cause the fluid to be pulled from a higher pressure section of the apparatus  100  toward a lower pressure section of the apparatus  100 . 
     The energy extraction device  106  may be located along a path of the fluid flow Z from the inlet  110  of the channel  104  to the plenum  116  and further to the outside environment. The energy extraction device  106  can be configured to obtain energy from the fluid flow Z by passing the fluid along and/or through a portion of the energy extraction device  106 . The energy extraction device  106  can comprise an electric generator, a hydraulic pump, or the like. For example, illustrated in  FIG. 1 , where the energy extraction device  106  comprises an electric generator including a rotating fan, the rotating fan can be placed in the channel such that the fluid passes through the fan causing the fan blades to rotate and generate energy. Additionally, although illustrated in  FIG. 1  as having a single energy extraction device  106 , the apparatus  100  may include any number of energy extraction devices. 
     The energy extraction device  106  can be located at any suitable position along the flow path from the inlet  110  of the channel  104  to the plenum  116  and further to the outside environment. For example, as shown in  FIG. 1 , the energy extraction device  106  can be located in the channel  104  between the inlet  110  and the outlet  112 . In another embodiment, the energy extraction device  106  can be located where the outlet  112  of the channel  104  connects to the plenum  116 . In a yet further embodiment, the energy extraction device  106  can be located near the aperture  120  between the plenum  116  and the outside environment. 
     The control system  108  may be configured to receive an input and to modify the pressure differential between the plenum  116  and the inlet  110  of the channel  104  based on the received input. In one embodiment, the input can signify a characteristic(s) of the outside environment. The characteristic(s) of the outside environment can include at least one of humidity, temperature, airflow direction, airflow velocity, or the like. In another embodiment, the input can signify a characteristic(s) of the fluid flow within the apparatus  100  described above. 
     In one embodiment, the input can include data supplied by a sensor that is part of the control system  108  or in communication with the control system  108 . For example, the sensor may be located along the flow path of fluid in the apparatus  100 . The sensor can be configured to output a signal that is indicative of the characteristic(s) of the fluid flow (e.g., amount, velocity, etc.) at the sensor location. In another example, the sensor can be configured to output a signal that is indicative of an amount of energy being extracted by the energy extraction device  106 . In a yet further example, the sensor may be configured to output a signal that is indicative of the characteristic(s) of the outside environment. 
     In another embodiment, the input can include data from a database. The database may include historical characteristic(s) of the outside environment and/or historical characteristic(s) of the apparatus  100 . The historical characteristic(s) may include previous meteorological patterns, amount of energy extracted at a specific time or over a specific time period, or the like. The database may include projected characteristic(s) of the outside environment, such as forecasted meteorological patterns. 
     The control system  108  may modify the fluid flow between the plenum  116  and the inlet  110  of the channel  104  by modifying operational setpoints for the energy extraction device  106 . For instance, the energy extraction device  106  can include a propeller with variable speed and/or variable blade pitch. The control system  108  may modify the rate of fluid flow by either speeding up or slowing down rotation of the propeller. An increase in propeller rotation speed can cause an increase in fluid flow rate. 
     The control system  108  may modify the pressure differential between the plenum  116  and the inlet  110  of the channel  104  by modifying fluid flow Y between the plenum  116  and the outside environment. Because the control system  108  may modify the fluid leaving the plenum  116  and therefore lower the average pressure in the plenum  116 , the control system  108  may modify the pressure differential between the plenum  116  and the inlet  110  of the channel  104 . By extension, the control system  108  can modify the amount and/or velocity of flow from the inlet  110  of the channel  104  to the plenum  116  and the amount of energy obtained by the energy extraction device  106 . Where the energy extraction device  106  comprises a generator with a fan, modifying the velocity of flow from the inlet  110  of the channel  104  to the plenum  116  may further be used to modify the speed at which the fan rotates. The control system  108  may further be configured to prevent fluid flow from the apparatus  100  to the outside environment by closing the fluid connection between the apparatus  100  and the outside environment. 
     In an embodiment, the control system  108  may modify the fluid flow Y between the plenum  116  and the outside environment by pivoting the assembly  102  with respect to a direction of oncoming fluid X flow in the outside environment, the angle of attack. In this embodiment the assembly  102  may be pivotally connected to the channel  104  such that the assembly  102  pivots about an axis of rotation extending through a center of the outlet  112  of the channel  104 . In an example of this embodiment, where the body  114  comprises an airfoil, the control system  108  can pivot the airfoil such that the leading edge of the airfoil faces into the oncoming fluid X. 
     In one version of this embodiment, illustrated in  FIG. 2 , the control system  108  comprises a passive system  200  (e.g., similar to a wind vane, windsock, etc.) configured to passively rotate the assembly  102  based on the direction of the oncoming fluid X. The passive system  200  can be attached to a longitudinal end of the assembly  102  and be configured to rotate the assembly  102  as the passive system  200  rotates into the oncoming fluid X. Alternatively, the passive system  200  can be located at other parts of the assembly  102 , for example along the leading edge of the airfoil or the like. In yet another example, the assembly  102  can be designed and weighted such that a portion of the assembly  102  points towards incoming fluid flow. 
     In another version of this embodiment, illustrated in  FIG. 3 , the control system  108  comprises an active system  300 . In this embodiment, the active system  300  may include a sensor configured to output a signal that is indicative of a direction of the oncoming fluid X and a mechanism (e.g. motor, gear system, etc.) configured to pivot the assembly  102  based on the output of the sensor. The illustrated version of the control system  108  comprises a plurality of gears  302  that may be configured to pivot the assembly  102 . At least one of the plurality of gears  302  may be connected to a motor via pinion engagement (not shown). In addition, at least one of the gears  302  can include a chamfer configured to prevent accidental rotation of the gear  302 . Further, at least one of the gears  302  can include slots and a corresponding gear  302  can include a pin extending through the slot to define rotation limits for the slotted gear. In the illustrated version, at least one gear  302  of the system of gears is located between the assembly  102  and the outlet  112  of the channel  104 , however the plurality of gears and/or the motor can be located at any suitable position with respect to the assembly  102 . 
     In another embodiment, the control system  108  can modify the fluid flow through the apparatus  100  by modifying an interior volume of the plenum  116  and/or the channel  104 . By modifying the interior volume of the plenum  116  and/or the channel  104 , the control system  108  modifies the amount of fluid necessary to adjust pressure therein. Modifying the interior volume of the plenum  116  and/or channel  104  can also control the velocity of fluid flow therethrough. 
     In a version of this embodiment, illustrated in  FIG. 4 , the control system  108  can include an adjustable choke  400 , that can adjust rotationally along arrow A, configured to adjust the interior volume of the channel  104 . In another version, the control system  108  can include a sleeve located at a portion (e.g., the channel  104  and/or the plenum  116 ) of the apparatus  100  configured to adjust in size to adjust the interior volume of the portion. 
     In yet another embodiment, the control system  108  can modify the fluid flow Y between the plenum  116  and the outside environment by modifying a size of the aperture  120 . By modifying the size of the aperture  120 , the control system  108  can modify the rate of fluid flow Y from the plenum  116  to the outside environment. For example, by decreasing the size of the aperture  120  the control system  108  may decrease the rate at which pressure decreases in the plenum  116 . By extension, decreasing the rate at which pressure decreases in the plenum  116  further decreases the rate of fluid flow Z from the inlet  110  of the channel  104  to the plenum  116 . 
     In a version of this embodiment, the control system  108  can comprise an adjustable shutter configured to modify a size of the aperture  120 . In another version of this embodiment, illustrated in  FIG. 5 , the assembly  102  includes a plurality of apertures  120  and the control system  108  includes a corresponding number of separate adjustable shutters  500  each configured to modify a size of a corresponding aperture  120 . In yet another version of this embodiment, the assembly  102  includes a plurality of apertures  120  and the control system  108  includes an adjustable shutter configured to adjust the apertures  120  in sequence, e.g. closing an aperture  120  before proceeding to adjust the next aperture  120  in the sequence. 
     In the embodiments illustrated above, the plenum  116  and the corresponding aperture(s)  120  are formed by the body  114  comprising a single unit. Turning now to  FIGS. 6-9   c , illustrated is an assembly  102  comprising varying alternatives for forming the plenum  116  and/or the aperture(s)  120 . In the illustrated embodiments, the assembly  102  includes a structural frame/skin  600  (hereinafter “frame  600 ”) with an indentation and an insert  602  that may be removably placed within the indentation. The insert  602  and the frame  600  can be made of the same material or can be made of different material. For instance, to reduce the cost of changing aperture  120  and/or plenum  116  size and/or arrangement, the frame  600  can be made of aluminum extrusions, carbon fiber pultrusion, or the like while the insert  602  is made of lower cost material (e.g. plastic). 
     The insert  602  can include the plenum  116  and/or the aperture(s)  120 . The use of an insert  602  may allow a user to manufacture a single frame  600  while allowing the user to adjust the size of the plenum  116 , the size of the aperture(s)  120 , the number of apertures  120 , the orientation of the aperture(s)  120 , and/or the like. The adjustment may be based on the setting of the assembly  102 . The insert  602  and the frame  600  may be configured such that when the insert  602  is removably secured in the indentation, the insert  602  is flush with the frame  600  as can be seen in  FIG. 6 . However, the insert  602  need not be flush with the frame  600  and can have any position consistent with the intended use. 
     To prevent the insert  602  from unintentionally coming out of the indentation during use, at least one of the insert  602  or the frame  600  can be configured to removably secure the insert  602  in place. For example, the insert  602  can comprise portions of varying size. In one embodiment, illustrated in  FIG. 6 , the insert  602  may include a cylindrical portion forming the plenum  116  and a smaller portion extending therefrom including an aperture  120 . Consequently, the indentation may include a corresponding outline. In another embodiment, illustrated in  FIG. 7 , the indentation may include a stepped outline with a larger and a smaller trapezoidal section. The insert  602  may have a corresponding shape. In a yet further embodiment, the insert  602  can comprise a plate including an aperture  120 . The frame  600  defines the plenum  116  and when the insert  602  is attached to the frame  600  the plenum  116  is at least partially enclosed by the combination of the frame  600  and the insert  602 . 
     In a yet further embodiment, illustrated in  FIGS. 8 a  and 8 b   , the frame  600  and the insert  602  can include corresponding locking tabs  800  and  802 . The locking tab(s)  800  formed on frame  600  can include a first arm extending inwardly into the indentation and a second arm extending radially therefrom. The locking tab(s)  802  formed by the insert  602  can comprise corresponding structure configured to abut a juncture formed by the first arm and the second arm when the insert  602  is inserted into the frame  600 . 
     As discussed above, the use of an insert  602  can allow a user to adjust the type, the number, and/or the orientation of the aperture  120  without having to remove the entire assembly  102 .  FIGS. 9 a -9 c    illustrates various alternatives for aperture  120  arrangement on the insert  602 . For example, as illustrated in  FIG. 9 a   , the aperture  120  can comprise a longitudinal slot and the insert  602  can include a plurality of apertures  120  arranged longitudinally. In another example, the aperture  120  can comprise an angled vortex generator. The insert  602  can include a plurality of the apertures  120  that are alternating, as illustrated in  FIG. 9 b   , and/or aligned, as illustrated in  FIG. 9   c.    
     Turning now to  FIGS. 10 and 11 , illustrated is an embodiment of the apparatus  100  including two assemblies. The two assemblies can be arranged to form a corridor therebetween. For example, in an embodiment, illustrated in  FIG. 10 , the assemblies  1000  and  1002  are arranged parallel to each other along a longitudinal axis and are spaced a distance from each other to define the corridor  1004  therebetween. In another embodiment, illustrated in  FIG. 11 , the assemblies  1100  and  1102  are circular and have different diameters, the assemblies have a concentric arrangement to define the corridor  1104 . The two assemblies can be arranged in any configuration sufficient to form the corridor therebetween. The corridor  1004  may take any suitable shape and/or orientation (e.g. horizontal, vertical, circular, triangular, etc.). 
     Arranging two assemblies to form a corridor therebetween can provide certain benefits. For example, the use of a corridor can cause up to a 20-fold increase of outside environment fluid flow pressure exerted on each body of the assemblies before flow begins to break down due to viscous forces in the outside environment fluid flow. Additionally, the use of a corridor can cause an increase in velocity of fluid flow through the apparatus  100  because of the increased pressure. 
     In the embodiment illustrated in  FIG. 10 , the two assemblies  1000  and  1002  may be arranged such that the oncoming fluid X flow through the corridor  1004  therebetween has a lower pressure than the surrounding oncoming fluid X flow. Consequently, the side of each assembly  1000  and  1002  that faces inwardly into the corridor  1004  may act as a suction surface and the side of each assembly  1000  and  1002  that faces outwardly from the corridor  1004  may act as a pressure surface. In this arrangement, the aperture  120  of each assembly  1000  and  1002  may be located on the suction surface so as to face into the corridor  1004 . Therefore, the fluid in the plenum  116  of each assembly  1000  and  1002  may be configured to flow into the corridor  1004  when the average pressure in the corridor  1004  is lower than the average pressure in the plenum(s)  116 . 
     Alternatively, in the embodiment illustrated in  FIG. 11 , the suction surface of each of the assemblies  1100  and  1102  may be placed in tandem, i.e. both suction surfaces are on the inner side of each respective ring-shaped assembly  1100  and  1102 . The ring-shaped assemblies  1100  and  1102  can be arranged to amplify the wake expansion caused by oncoming fluid X flow through the ring-shaped assemblies  1100  and  1102 . The outer ring-shaped assembly  1100  may use the presence of the inner ring-shaped assembly  1102  to amplify the wake. The inner ring-shaped assembly  1102  may use the opposing ends of the inner ring-shaped assembly  1102  to amplify the wake. 
     In the embodiments illustrated in  FIGS. 10 and 11 , the two assemblies  1000  and  1002 ,  1100  and  1102  respectively, are shown sharing a channel  104  and an energy extraction device  106 . Alternatively, each of the two assemblies  1000  and  1002 ,  1100  and  1102  respectively, can have a separate channel  104  with an energy extraction device  106  located therein. The separate channels  104  can each be connected to a main channel thus sharing a common inlet or each can have their own separate inlet. Any suitable arrangement of channels and/or energy extraction devices is hereby contemplated for the use of a plurality of assemblies. 
     The embodiments illustrated in  FIGS. 10 and 11  further include the control system  108 , similar to the one described above, configured to modify a pressure differential between the plenum  116  of each assembly and their corresponding channel inlet. The control system  108  can be configured to modify each assembly separately and/or synchronously. As discussed above, the control system  108  is configured to modify the pressure differential based on the received input. 
     For example, in the embodiment illustrated in  FIG. 10 , the apparatus  100  can further include a plate  1006  that both assemblies are attached to. In this embodiment, the plate  1006  is located between and attached to both assemblies and the outlet  112  of the channel  104 . The plate  1006  can include therein fluid flow path(s) connecting the outlet  112  of the channel  104  and each of the assemblies. The plate  1006  can be pivotably attached to the channel  104  such that the control system  108  can pivot the assemblies synchronously by pivoting the plate  1006 . The apparatus  100  can further include a top cover (not pictured) opposite the plate  1006 . The assemblies can be pivotally attached to the top cover in addition to being pivotally attached to the plate  1006 . 
     In another example, the control system  108  can be configured to modify the distance between the two assemblies. By adjusting the distance between the two assemblies, the control system  108  can modify the average pressure in the corridor  1004  between the two assemblies. Modifying the average pressure in the corridor  1004  can, by extension, modify the amount of energy extracted from the fluid flow within the apparatus  100 . 
     In yet another example, the control system  108  can be configured to separately modify the angle of attack of each assembly. By adjusting the angle of attack for only one of the two assemblies, the control system  108  can taper the corridor  1004  therebetween along the length of the assemblies. This tapering can be seen in  FIG. 12 . 
     Turning to  FIG. 12 , illustrated is an embodiment of mechanisms that can be used to modify the distance between and/or the angle of attack for each of the pair of assemblies  1000  and  1002  from  FIG. 10 . The illustrated mechanism comprises one possible embodiment of structure capable of modifying the distance between and/or the angle of attack for each of the pair of assemblies and any suitable structure and/or system is hereby contemplated. In the illustrated embodiment, the mechanisms may comprise a plurality of rods  1200  connected to each of the assemblies  1000  and  1002  that can be configured to move at least a portion of each of the assemblies  1000  and  1002 . The mechanism further includes a plate  1202 , the plate  1202  can be the same plate  1006  discussed above with reference to  FIG. 10  or can be a separate plate. Further, The plate  1202  further includes a plurality of sleeves, the number of sleeves can correspond to the number of rods  1200  or can vary. Each rod  1200  can slidably be placed in a corresponding sleeve. Because the rod  1200  is connected to an assembly  1000  and  1002 , sliding movement of the rod  1200  in the sleeve can cause corresponding movement in the attached assembly  1000  and  1002 . The number of rods  1200  attached to each of the pair of assemblies  1000  and  1002  can be the same, as in the illustrated embodiment, or can differ. 
     In the illustrated embodiment shown in  FIG. 12 , the mechanism includes two rods  1200  for each of the assemblies  1000  and  1002 . With reference to a first of the assemblies  1000  and  1002 , a first rod  1200  is attached to a first portion of the assembly and a second parallel rod  1200  is attached to a second portion of the assembly. The distance between the first assembly and the second assembly can be adjusted by moving the first and second rod  1200  in the same direction in unison. The angle of attack for the first assembly can be adjusted by moving one rod  1200  while keeping the other stationary or by moving the rods  1200  in opposite directions at the same time. Further, while not depicted, a top cover can be arranged in parallel with the plate  1202 , such that fluid is directed between the assemblies  1000  and  1002 . 
     The control system  108  can further include an actuator configured to adjust the position of the rods  1200  based on the received input. Each rod  1200  can have a separate actuator or at least two of the rods  1200  can share an actuator. The actuator can comprise any suitable mover (e.g. hydraulic, pneumatic, mechanical, electrical, etc.). 
     In an embodiment, illustrated in  FIG. 13 , the apparatus  100  can include a plurality of separate assemblies  102 . A control system  108  for the plurality of separate assemblies  102  can be configured to separately modify the pressure differential between the plenum  116  and the inlet of the channel  104  based on received input. For example, the control system  108  can adjust the angle of attack of one of the assemblies  102  while the other assemblies  102  remain static. Alternatively, the control system  108  for the plurality of separate assemblies  102  can be configured to synchronously adjust the angle of attack for more than one of the assemblies  102 . 
     In another embodiment, the apparatus  100  can include a plurality of paired assemblies  1000  and  1002  as described above with reference to  FIG. 10 . As illustrated in  FIG. 14 , the plurality of paired assemblies  1000  and  1002  can be arranged sequentially along a shared channel  104  with an energy extraction device  106  arranged in the channel  104  before the first paired assemblies  1000  and  1002  in the sequence. In the illustrated embodiment, the plurality of paired assemblies  1000  and  1002  are arranged side by side. In another embodiment, the plurality of paired assemblies  1000  and  1002  are arranged longitudinally such that the corridor  1004  of each of the paired assemblies  1000  and  1002  are in sequence. 
     In another embodiment, the apparatus  100  includes an energy extraction device  106  before each of the paired assemblies  1000  and  1002  in the sequence. The plurality of paired assemblies  1000  and  1002  can be arranged parallelly, as illustrated, or can be arranged in any suitable formation. Additionally, the embodied apparatus  100  can be placed on a building (e.g. house, store, skyscraper, etc.) to take advantage of wind flowing against the building. 
     In yet another embodiment, the apparatus  100  includes a plurality of paired assemblies  1000  and  1002  as described above in different orientations. As illustrated in  FIG. 15 , the apparatus  100  includes at least one pair of assemblies  1000  and  1002  orientated vertically and one pair of assemblies  1000  and  1002  orientated horizontally. Further, as shown in the illustrated embodiment, the apparatus  100  can be placed on the roof of a building (e.g. house, store, skyscraper, etc.) to take advantage of wind flowing over the roof of the building. 
     In a yet further embodiment, illustrated in  FIG. 16 , a corridor is created between an assembly  1600  and a nonadjustable surface acting as the second assembly. In the illustrated embodiment, the nonadjustable surface comprises a roof  1602  of a house and the assembly  1600  can be positioned parallel to the roof  1602 . The nonadjustable surface can comprise any desired surface including a building wall, exterior of a vehicle, or the like. Further, the assembly  1600  can be positioned in any suitable arrangement with respect to the nonadjustable surface. For instance, in the illustrated embodiment, the assembly  1600  is located at the peak of the roof. In another embodiment, the assembly  1600  is located at a portion of the roof other than the peak. 
     In the illustrated embodiment, the channel  104  may extend along a side of the house with an inlet at a base of the house. The energy extraction device  106  may be placed near the inlet of the channel  104  as illustrated to make repair easier, however the energy extraction device  106  can be placed anywhere along the apparatus  100 . For instance, the energy extraction device  106  can be located in the channel  104  adjacent the assembly  106 , within the housing structure, or in a section of the channel  104  extending along a wall of the housing structure. 
     In yet another example, the suction effect at the inlet of the channel caused by lowering the pressure in the plenum may be used as part of a pumping system in lieu of or in addition to generating energy. For instance, the apparatus  100  may be employed without an energy extraction device  106  to be used as part of a pumping system. In another instance, the apparatus  100  may be employed as part of a pumping system and may include an energy extraction device  106  to extract energy as the fluid pump throughs the apparatus  100 , as described above. In one example, the apparatus  100  can be used as part of an air conditioning system to pump air from one location, namely the inlet  110  of the channel  104 , to a second location. In another example, the apparatus may be placed on an ocean, lake, or river floor and may be used to pump water from an inlet  110  of the channel  104  to a second location. 
     What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable modification and alteration of the above devices or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art can recognize that many further modifications and permutations of various aspects are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.