Hydrokinetic Energy

Abstract

This proposal is for hydrokinetic energy research, construction, and generation. The primary energy producing device is a low disturbance design that is currently producing power and has UNC provisional patent IP protection. The budget includes support for multi-disciplinary and multi-university components covering the engineering, construction of a full scale test facility, lab and field testing, leveraging of funding, manufacturing, and jobs creation. 

The multidisciplinary participant researchers from UNC Charlotte will handle mechanisms, computational fluid dynamics (CFD), controls, construction, and marketing to the public.  Researchers from NC A&T will provide expertise in controls (but on a separate proposal). Researchers from NC State will be supporting the interaction with the off shore/sea floor foundations.

Chronologically, this proposal describes the construction and testing in the first year in detail and also proposes five year development and commercial production plans.

Introduction

This proposal is for the development, construction, and testing of a broad range of hydrokinetic energy generation systems.  The first design is currently in testing and has intellectual property (IP) protection with the US Patent and Trademark Office (USPTO). The PI has 35 years of industrial experience and believes that there is a potential to set up a factory to produce these devices employing several dozen North Carolina citizens.

The multi-disciplinary and multi-university budget includes support for:

  • a 1 meter recirculating water tunnel,
  • a completed device in testing,
  • intellectual property on the invention,
  • construction of a second device in the design stage,
  • mechatronics engineering, and power generation,
  • sea floor mooring, and environmental impact,
  • plans for a kW device and a MW device,
  • and plans for manufacturing and jobs creation.  

The multidisciplinary participant researchers from UNC Charlotte will handle mechanisms, computational fluid dynamics (CFD), environmental impact statement, and marketing to the public and to the government.  Researchers from NC A&T will provide expertise in automatic controls. Faculty from NC State will be supporting the off shore/sea floor foundations.  Chronologically, this proposal describes the first year construction plans in detail and also proposes five year development and commercial production plans. 

The Generation V, Off-shore Test Facility

The primary design goal is a device configured to generate power in high flow velocity and less confined environments such as a narrow inlet or river. 

The crux of the design is to have a wing in a flow of water that generates lift.  The lift force drives the wing upwards and the force times the velocity upwards is converted to electrical energy.  At the top of its stroke, the symmetric wing inverts and drives downwards also generating electricity. A cambering wing is being reviewed for performance.

Figure 1. Generation V facility being serviced in shallow water by scuba divers.

As per the artist’s rendition, the “Flying Wing” is mounted on a “Long Arm” with the generator up and out of the water thus leaving the complex electrical generation equipment out of the water where it can be more easily serviced.  This avoids the cost of complete sealing and the recurring cost of scuba diver support of the generation equipment.  In this design, the only things under water are the wires to the mainland.

In addition, and not shown is a counterweight system that allows raising the wing out of the water for easier servicing. This system allows the wing to be raised high enough to be put on the deck of a pontoon boat type service vehicle.  The 50 foot “long arm” can then be disconnected for shore based servicing if needed.

The Generation VI Wave Test Facility

Figure 2. Generation VI wave facility being serviced in shallow water by scuba divers.

The generation five design above was also adapted to handle a wave generation system and is referred to as the generation six design.  This configuration uses 90% of the tidal generation system in order to simplify the installation and save money on the construction.  This not only saves money in the installation but also speeds up the time needed to manufacture it for testing.  In the artist’s rendering, the floats are standard polyethylene 55 gallon drums mounted on steel pipes.

Like the tidal version, the wave test facility also has the ability to service without scuba divers and the removal of the long arm without getting (too) wet.

The current Generation I “Flying Wing” Test Facility

Figure 3. The Test Flying Wing system submerged in the UNC Charlotte Water Tunnel

 

Figure 4. Artists depiction of Flying Wing system mounted on the UNC Charlotte Water Tunnel

The first generation design was developed to generate power in high flow velocity-confined environments such as a narrow stream.  The system is shown in the figure below is mounted on the UNC Charlotte Water Tunnel in test mode.

The figure above shows details of the system with respect to the wing cambering system.  The overall length is just over 18 feet.

Figure 3 shows a close up of the flying wing in the water tunnel.  The frame is stainless steel and the aluminum wing is a NACA 0018 profile formed over seven wing spars and has an 18” stroke.

Performance results from the Generation I facility

The figure below shows the Particle Image velocimetry (PIV) streamline measurement results of the water tunnel tests.  As can be see, the flow is highly efficient and shows no trailing vortices in the wake of the wing.

Power tests were run with the first generation system resulting in a maximum 3.02 watt

Figure 5. Generation I Hydrokinetic Power vs. Flow Speed

 

Figure 6. PIV Experimental Results of Flow Streamlines and Velocity Past Wing

output.  Power was produced by a DC gear motor/generator via nylon coated stainless steel cable wrapped four times around a Æ2” (Æ50.8 mm) x 40” (1016 mm) long drum transverse to the flow direction.  To avoid torquing the “long arm”, two cables were used, one at the near side and one at the far side of the “flying wing”.  The motor/generator was fixed to the frame whereas the cables were attached top and bottom the “long arm” (getting wet at the bottom).  An alternate approach where the cable stayed dry and the drum-motor/generator moved up and down was ruled out due to the stress on the “long arm” counter weight.

The power generated came from a DC Motor/Generator and produced positive DC power on each up-stroke and negative DC power on the down-stroke.

The Large Recirculating Water Tunnel

The Large Recirculating Water Tunnel is a test facility constructed by the PI for the purpose of research on fluid flows.  Of the hundreds of water tunnels in the US, the facility at UNC Charlotte is ranked fifth (by flow rate).  Since the PI built this facility, it is permanently available for use and is currently in use for hydrokinetic energy extraction research.  The advantages are not only availability to a great test facility, but that it also allows for full scale testing of the original prototype at speeds up to 1 m/s.

 

Figure 7. The Large Recirculating Water Tunnel at UNC Charlotte

The performance of the facility is multi-fold.  Since it is a recirculating water tunnel, it can run continuously and (for example) is sometimes left running overnight to assist in the filtration system cleaning up settled debris.

The test section is at the exit of a boundary layer reducing nozzle and is 3 meters long by 1 meter deep and 1 meter wide and as shown in some of the images, is completely surrounded by viewing windows.  The top is open although it has removable Lexan debris covers.  The Hydrokinetic Energy device accesses the water via a small slit in the covers.  The Large Recirculating Water Tunnel is located in the Alan Kulwicky Motorsports Shop on the campus of the University of North Carolina at Charlotte.

Instrumentation Associated with the Test Facility

The most powerful instrument associated with the water tunnel is a Dantech 3D Particle Image Velocimetry system (3D-PIV).  This $250,000 system allows measurement of the flow at all locations simultaneously in a plane defined by a powerful laser.

Normally, a computer controlled two axis traverse moves the object of interest around in the laser sheet measurement plane; however, it is also configured to move the Laser back and forth around a stationary flow object.  In addition, observing the flow patterns is supported by both Hydrogen bubble and Oxygen bubble generation stingers using an electrolysis system.  Normally only Hydrogen is used; however, at the very high speeds, Hydrogen becomes too faint for observational use and the larger Oxygen bubbles are better suited.

Figure 8. Generation II wave test facility for testing in the hole at Jenette’s pier.

The Generation II Wave Test Facility for Jenette’s pier (in year one)

To validate the efficacy of the Generation II Wave test device, a simple frame will be constructed in the first summer and will mount in the hole in Jenette’s pier.  This device will take advantage of the cable drive mechanism developed for the first water tunnel test.

This system will allow power generation measurements in a controlled environment and validate some of the reliability questions with respect to the components.  Furthermore, this system will allow a review of several of the corrosion solutions being developed for the collection of devices.

The floats are standard 55 gallon polyethylene drums mounted on steel pipes at their center.

Unlike the offshore devices, the application at Jenette’s pier will allow servicing via the motor/generator.  That is, power can be applied to the motor/generator to drive the floats up out of the water and up to the pier.

The Generation III & IV Bridge Pier Test Facility

Figure 9. Generation III tidal facility tied to bridge pier

The second generation design was also configured to be able to attach to a bridge pier.  This not only saves money in the installation but also speeds up the time needed to manufacture it for testing.  In the artist’s rendering, the most complex addition is the clam shell mounting bearing.  The power generated would initially be dissipated in warning lights.  It should also be noted that due to its proximity to land (or bridge) maintenance would be streamlined due to the improved access.

Figure 10. Generation IV wave facility tied to bridge pier

One final note is that this bridge pier mounting also could be set up with the wave energy system (Gen VI) and be used on a bridge pier or at the Jenette’s pier.

The Generation VII Test Facility

Figure 11. Generation VII facility being serviced in deeper water by scuba divers (seen at the base of the left leg).

The third generation facility was designed to generate MW power in the Gulf Stream.  The artist’s rendering shows a giant version of the Generation II facility; however, it is thought that this will probably need to be changed to be moored to the sea floor with cables due to the extreme depths associated with the Gulf Stream.

Intellectual Property

The PI has a track record in protocols of the US Patent and Trademark Office, (USPTO) and is listed as an inventor eight times  He has also written a patent application (still pending) singlehandedly.  With this skill set, he has performed a patent search on the above described hydrokinetic energy device. 

The result is a Provisional Patent application protecting the rights of the University of North Carolina system with regard to the invention.  Of the hundreds of patents reviewed, approximately 43 patents were felt to be similar enough in scope to be included in the research area of this invention.

With the help of the Office of Technology Transfer in the Charlotte Research Institute (CRI), (who also funded the hydrokinetic prototype), the PI has constructed a prototype for testing and produced power.

Siting and Permitting

The second generation test facility will require expertise in siting and permitting.  Since the PI is neither an expert on this nor currently knows of an expert, experts will be brought in to assist in this task in the second year.

Mammal and Fish Interaction

Since one of the beneficial features of the Flying Wing design and the wave energy system are their low impact interaction with water born mammals and fish, a study of that interaction is included.  The goal of this study is to evaluate and minimize the interaction.  This may include adding features such as lights or acoustic markers or may find that nothing is needed.

Public Engagement and Outreach

The PI plans to promote the hydrokinetic energy device with the general public.  The PI enjoys and has considerable experience with public engagement and outreach.  He currently manages an NSF program that includes outreach to high school students and is focused on recruitment into engineering.  As a result, the PI has had several public outreach open houses in the Alan Kulwicky Memorial Race Shop housing the Water Tunnel.  These typically include inviting prospective families to the shop and grilling up lunch.

In addition, the PI has reached the broader public through stories in Road & Track magazine, the Charlotte Business Journal, and with Reuters.

Testing Marine Mammals and Fish interaction

The testing at a facility like Jenette’s Pier would also allow testing of any interaction with fish and marine mammals.  One of the key features of the Flying Wing and the wave energy designs are their presumed low impact presence of marine life.  That is, they are different than rotating turbines (similar in concept to the ubiquitous wind turbines).  However, since this has not been verified, a team of zoologists will study the interaction with a lookout for ill side-effects.

Sea Floor Foundations

Any generation facility will eventually need to be tied to the sea floor.  Although essentially a bridge pier, the foundation of the hydrokinetic energy system will be carrying a continuously oscillating load and thus require special consideration.  A civil engineering professor from NC State has been tasked with the analysis of sea floor attachment types.

The proposed Flying Wing will require at least two separate mooring system designs: one for near-shore installations and another for off-shore installations. In both cases, the Flying Wing will be affixed to the seafloor with a rigid pile foundation, but stabilization in each case will vary. For the near-shore installation, it is expected that anchored guy wires may be sufficient for base stabilization, so this option will be investigated first. Off-shore installations will likely require either bipedal or tripedal foundation installations, possibly including suction caissons, driven plates, and/or fluke anchors.

Matching Funding

It should be mentioned that in the last three years, the PI (Dr. Tkacik) has made 22 research Grant Proposals with 10 awards.   From this, a case can be made that the PI (Dr. Tkacik) plans to and will be making proposals to the NRCS Conservation Innovation Grants (CIG), the National Science Foundation, the Department of Energy, the Department of the Navy, and to nongovernmental entities. 

Jobs Creation

Also from a credibility standpoint, the PI spent thirty years in industry prior to becoming a professor.  In his last role, he spent ten years as VP of engineering with responsibilities for 53 plants (mostly in the southeastern US). Putting one plant together to make these devices is within his range of abilities.  Since the designs are expected to prove highly efficient and cost effective, a manufacturing facility is also planned. 

Initially, this would be for the production of farms of generators; however, the program is scalable for major production.  It is envisioned that an initial production facility of 30,000 ft2 employing ten NC workers while using trucking services of NC based firms will avoid the leasing costs of tractors and trailers.  An evaluation through the NC Commission on Workforce Development of employment rates will be used to determine the greatest need and the easiest location for hiring (greatest unemployment rate) in the state.

Summary

This proposal is for hydrokinetic energy research, construction, and generation. The primary energy producing device is a high efficiency design that is currently producing power and has UNC provisional patent IP protection. The budget includes support for multi-disciplinary and multi-university components covering the engineering, construction of a full scale test facility, lab and field testing, leveraging of funding, manufacturing, and jobs creation.