Patent Application
20190084676
The present subject matter relates generally to wind turbines and, more particularly, to systems and methods for providing visual identification of wind turbine airflow.
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. For example, rotor blades typically have the cross-sectional profile of an airfoil such that, during operation, air flows over the blade producing a pressure difference between the sides. Consequently, a lift force, which is directed from a pressure side towards a suction side, acts on the blade. The lift force generates torque on the main rotor shaft, which is geared to a generator for producing electricity.
Visualizing aerodynamic flow fields is a challenging task. In general, flow visualization has been employed by scientists and engineers for many years. More specifically, some basic components of experimental flow visualization include (1) an element or tracer that tracks the flow (e.g. certain types of particles or a property of the fluid such as density), (2) an observer (e.g. the human eye or a digital capture device that can see the tracer motion or lack thereof), and (3) a system that interprets the observed motion of the tracer, or synchronizes said motion with some other quantity (time, flow rate, etc.). Such steps generally result in an improved understanding of the flow field of interest.
Flow visualization typically occurs under controlled conditions in a wind or water tunnel. In other situations, flow visualization is attempted (or occurs naturally) in less-predictable field conditions. Flow fields can be visualized in free space or near solid surfaces. Examples of common techniques include surface methods like oil flow visualization or pressure sensitive paint (steady or unsteady), particle tracer methods (e.g. smoke, microspheres, or bubbles of some sort visualized with high-speed cameras, photogrammetry, particle image velocimetry or laser Doppler velocimetry), and/or optical methods that rely on variations in refractive index (e.g. Schlieren, shadowgraph, and interferometry).
Wind tunnel flow visualization, though routinely performed, is limited to a narrow range of freestream turbulence levels and length scales. Further, if modeling an entire wind turbine in the wind tunnel, the Reynolds number and/or reduced frequencies associated with the flow are likely different from field conditions. In the field, though the physics are realistic, the freestream conditions become uncontrolled and more uncertain. In addition, the physical size of modern utility scale wind turbines and the environmental conditions found in the field (e.g. moisture, vibration, temperature extremes, etc.) limits the applicability of many laboratory-friendly visualization techniques.
More specifically, challenges for full-scale wind turbine flow visualization include, at least, how to consistently release tracer particles at one point in a turbulent wind field at altitudes above ground level (e.g. at heights on the order of 200 meters), and how to place the observer in a position to steadily record and interpret the flow field that is revealed.
Accordingly, the present disclosure is directed to systems and methods for providing visual identification of wind turbine airflow that addresses the aforementioned issues.
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one aspect, the present disclosure is directed to a method for providing visual identification of a flow field across one or more wind turbines. The method includes releasing at least one tracer material from at least one predetermined location near the one or more wind turbines. The method also includes synchronizing the releasing of the tracer material with at least one of one or more operating parameters or one or more wind parameters of the one or more wind turbines. Further, the method includes monitoring, via one or more sensors, a resultant flow pattern of the tracer material.
In one embodiment, the method may include releasing the tracer material(s) in a continuous stream or one or more bursts. In another embodiment, the method may include releasing a plurality of tracer materials having a plurality of different colors. In further embodiments, the method may include releasing the tracer material(s) in a vertical line, a horizontal line, a grid pattern, or combinations thereof, or any other suitable pattern.
In additional embodiments, the step of releasing the tracer material(s) from the predetermined location(s) may include releasing the tracer material(s) from a first unmanned aerial vehicle (UAV) flying uptower, an uptower location on the one or more wind turbines, and/or one or more aircrafts. More specifically, in one embodiment, the method may include releasing the tracer material(s) from a tracer generator secured to a tether extending downward from the first UAV.
In several embodiments, the method may include receiving, via the first UAV, a remote triggering signal from an operator and releasing the tracer material in response to receiving the triggering signal.
In certain embodiments, the step of monitoring, via the one or more sensors, the resultant flow pattern of the tracer material may include providing a second UAV at an upstream location from the first UAV and monitoring, via at least one second sensor mounted to the second UAV, the resultant flow pattern of the tracer material.
In particular embodiments, the method may include directing the second sensor mounted to the second UAV downward toward a nacelle of one of the one or more wind turbines and adjusting, via the first UAV, at least one of a vertical position or a lateral position of the tracer material to target a desired area near the one or more wind turbines.
In yet another embodiment, the step of monitoring, via the one or more sensors, the resultant flow pattern of the tracer material may further include monitoring, via at least one of an additional UAV separate from the first and second UAVs or an additional sensor mounted to or near the one or more wind turbines, the resultant flow pattern of the tracer material.
In further embodiments, the method may include monitoring the resultant flow pattern of the tracer material from one or more uptower locations and/or one or more ground locations. In such embodiments, the uptower location(s) may include an upstream position relative to a rotor of the one or more wind turbines, a downstream position relative to the rotor, above a nacelle of the one or more wind turbines, below the nacelle, from a side of the nacelle, below the predetermined location, or another other suitable position uptower of the one or more wind turbines. In additional embodiments, the operating parameter(s) may include a turbine speed, a yaw angle, a pitch angle, a power output, a torque output, or similar. Further, the wind parameter(s) may include wind speed, wind turbulence, wind gust, wind shear, wind direction, or similar.
In specific embodiments, the tracer material may include solid particulates, liquid particulates, or combinations thereof.
In another aspect, the present disclosure is directed to a system for providing visual identification of a flow field across one or more wind turbines. The system includes at least one tracer material, a first aircraft at a first uptower location for releasing the at least one tracer material from at least one predetermined location of the one or more wind turbines, one or more sensors for monitoring a resultant flow pattern of the tracer material from one or more uptower locations, and a controller communicatively coupled to the one or more sensors. Further, the controller is configured for receiving data relating to the monitored resultant flow pattern and implementing a control action based on the resulting flow pattern.
In one embodiment, the first aircraft may include an unmanned aerial vehicle (UAV) or drone, an airplane, a helicopter, a rocket, a tethered balloon, a kite, or similar. In another embodiment, the system may also include a tracer generator and at least one tether secured to and extending downward from the first aircraft. In such embodiments, the tracer generator is configured for releasing the at least one tracer material.
In additional embodiments, the first aircraft may include a stabilizing device for stabilizing the predetermined location. For example, in such embodiments, the stabilizing device may include a parachute, a vertical stabilizer, a horizontal stabilizer, a kite tail, a wind screen, a mechanical tether connected to the ground, a gyroscopic mechanism, or any other suitable device for stabilizing the predetermined location (i.e. the release point of the tracer material).
In further embodiments, the system may also include a second aircraft adapted with one of the one or more sensors for further monitoring the resultant flow pattern of the tracer material.
In additional embodiments, the system may include an additional aircraft separate from the first and second aircrafts and/or an additional sensor mounted to or near the wind turbine for further monitoring the resultant flow pattern. It should be further understood that the system may further include any of the additional features described herein.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
In general, the present disclosure is directed to a system and method for providing visual identification of the flow field in proximity to a wind turbine using a combination of remotely-triggered pyrotechnic or aviation smoke tracers and one or more aircrafts, such as semi-autonomous unmanned aerial vehicles (UAVs). More specifically, in one embodiment, the method releasing the smoke from a consistent, repeatable point in space, regardless of the height above ground level, monitoring the resultant flow patterns from a variety of positions (e.g. downstream, above, to the side, and below the release point, and synchronizing the release of the smoke with the wind turbine operating parameters and/or the met mast data recorder or other atmospheric and/or wind data (e.g. from SODAR or LIDAR sensors).
Thus, the present disclosure provides many advantages not present in the prior art. For example, the flow field of the wind turbine can be easily visualized without the use of large, expensive cranes, man-baskets or cherry pickers. In addition, the GPS-based position-hold mode of the UAVs (when combined with image-stabilized, gimbaled cameras) provides a steady platform for data gathering. Moreover, the UAVs and tracer generators of the present disclosure are versatile and can be easily repurposed for different types of tracer release.
Referring now to the drawings,
As shown, the wind turbine 10 may also include a turbine control system or turbine controller 26 centralized within the nacelle 16. However, it should be appreciated that the turbine controller 26 may be disposed at any location on or in the wind turbine 10, at any location on the support surface 14 or generally at any other location. The turbine controller 26 may generally comprise as any suitable processing unit configured to perform the functions described herein. Thus, in several embodiments, the turbine controller 26 may include suitable computer-readable instructions that, when implemented, configure the controller 26 perform various different actions, such as transmitting and executing wind turbine control signals, receiving and analyzing sensor signals, and/or generating message signals. By transmitting and executing wind turbine control signals, the turbine controller 26 may generally be configured to control the various operating modes (e.g., start-up or shut-down sequences) and/or components of the wind turbine 10.
Referring now to
During operation of the wind turbine 10, it may be beneficial to monitor various operating and/or wind conditions of or near the wind turbine 10. For example, such parameters may be monitored and then utilized by the turbine controller 26 to implement a corrective action. Such corrective action may in turn reduce loads acting on the wind turbine 10, thereby increasing the operating life thereof. In one embodiment, it may be beneficial to visually detect a flow field of the wind turbine 10 as the flow field is generally indicative of wind turbulence, wind speed, and/or other wind parameters affecting operation and/or components of the wind turbine 10.
Accordingly,
In a preferred embodiment, as shown in
The tracer material(s) 42 described herein may include any suitable material having, for example, solid particulates, liquid particulates, or combinations thereof. More specifically, example tracer materials 42 may include, but are not limited to pyrotechnic smoke, aviation smoke, natural particles (e.g. fog, snow, sand, dust, etc.), foam or aerogel particles, as well as other extremely low-density materials such that the particle follows streamlines, retroreflective particles for which photogrammetry can be used for motion capture, steam or smoke utilizing any source of heat energy, chemiluminescent or fluorescent particles, soap bubbles or soap film, neutrally-buoyant weighted helium balloons or other neutrally buoyant objects, a plurality of micro-drones relaying position versus time telemetry, and/or any other suitable materials or particles.
In addition, the tracer material(s) 42 may also be suspended or released in several different ways. For example, in one embodiment, the tracer material(s) 42 may be release in a continuous stream or one or more bursts. Further, the tracer generator 45 may be suspended upstream, downstream, or in the rotor plane. Alternatively, the tracer generator 45 may be suspended from kites, balloons, or aerostats. Further, the tracer generator 45 may be suspended from strings or cables from the nacelle 16, such as between various objects/structures to create an array. As such, the tracer material(s) 42 can be released from the tracer generator at any suitable location, including for example, at the met mast, from the rotor blades 22, tower 12, nacelle 16, or a manned helicopter. Alternatively, as shown in
It should be understood that the tether(s) 47 described herein may have any suitable length depending on a desired release height of the tracer material(s) 42. For example, in one embodiment, the tether 47 may be long enough to remove the tracer source from the influence of drone prop wash. More specifically, in particular embodiments, the tether(s) 47 may be about ten (10) meters, but can vary with the drone type and payload weight. As such, in further embodiments, the tether(s) 47 may have a length that is less than 10 meters or greater than 10 meters.
Referring to
In further embodiments, as shown in
It should be understood that the tracer generator 45 can be designed to accommodate any number of tracer materials 42 having any suitable colors and can be arranged in a vertical line, a horizontal line, or grid pattern for increased contrast and data collection. For example, as shown in
In yet another embodiment, the tracer generator 45 may be secured to one or more of the rotor blades 22 or the rotor 20 while the turbine is either stationary or in motion. For example, as shown in
Referring back to
Referring back to
Multiple additional cameras 55 may also be positioned on the wind turbine 10 and/or its various components (i.e. the nacelle 16, the rotor blades 22, the rotor 18, and/or the tower 12 as well as on other solid mounting points such as the ground, met mast, crane, aircraft, vehicle, or kite) for further monitoring the resultant flow pattern 52. For example, as shown in
In addition, as shown in
Referring now to
As used herein, the term “processor” refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s) 64 may generally comprise memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD) and/or other suitable memory elements. Such memory device(s) 64 may generally be configured to store suitable computer-readable instructions that, when implemented by the processor(s) 62, configure the controller 60 to perform various functions including, but not limited to, transmitting suitable control signals to implement control action(s) in response to the resultant flow pattern 52 as described herein, as well as various other suitable computer-implemented functions.
Referring now to
Thus, as shown at 104, the method 100 also includes releasing at least one tracer material 42 from at least one predetermined location near the wind turbine 10 in response to receiving the triggering signal. More specifically, as mentioned, the tracer material(s) 42 may be released from one of the aircrafts 44, 54, 58, a downtower location of the wind turbine 10, and/or an uptower location on the wind turbine 10. In certain embodiments, the uptower location(s) may include an upstream position relative to the rotor 20, a downstream position relative to the rotor 20, above the nacelle 16, below the nacelle 16, from a side of the nacelle 16, below the predetermined location, or another other suitable location. In addition, in one embodiment, the method 100 may include releasing the tracer material(s) 42 from the tracer generator 45 secured to the tether 47 extending downward from the first UAV 44.
As shown at 106, the method 100 may also include synchronizing the releasing of the tracer material(s) 42 with at least one of one or more operating parameters or one or more wind parameters of the wind turbine 10. For example, in certain embodiments, the operating parameter(s) may include a turbine speed, a yaw angle, a pitch angle, a power output, a torque output, or similar. Further, the wind parameter(s) may include wind speed, wind turbulence, wind gust, wind shear, or similar.
As shown at 108, the method 100 includes monitoring, via one or more sensors 46, 48, 50, 55, a resultant flow pattern 52 of the tracer material(s) 42. As such, the method 100 of the present disclosure enables the visualization of the flow field in proximity to a utility-scale wind turbine or wind turbine model using multiple semi-autonomous UAVs.
In certain embodiments, the step of monitoring the resultant flow pattern 52 of the tracer material(s) 42 may include providing the second UAV 54 at an upstream location from the first UAV 44 and monitoring, via the sensor 48 mounted to the second UAV 54, the resultant flow pattern 52 of the tracer material(s) 42. In yet another embodiment, the step of monitoring the resultant flow pattern 52 of the tracer material 42 may further include monitoring, via the additional UAV 58 or the additional sensors 50, 55 mounted to or near the wind turbine 10, the resultant flow pattern 52 of the tracer material 42.
In particular embodiments, as shown in
In still further embodiments, the flow field of the wind turbine 10 may be observed using additional types of visualization. For example, lightweight streamers or ribbons can be deployed using all the methods described above. In addition, the visibility of the tracer material(s) 42 can be augmented with lasers or other focused light sources mounted to any portion of the wind turbine 10, UAVs, cranes, the met mast, and/or on the ground. The flow field may also be visualized using infrared cameras or film.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
