Hydricity Blog
Conceptual Designs
Conceptual Design 1: Vertical Design
The first design concept shown above consists of 4 collapsible tubes that oscillate back and forth as flowing water moves across them. The tubes are collapsible so that if the user wanted to move the device, he or she could collapse the tubes into being only 1 foot long as opposed to 3 feet long. There are also wheels attached to the bottom platform of the device so that the user can wheel the device to move it from one place to another. The top part of the device is made up of a very buoyant material so that it always stays above water to protect the electrical components sitting on top of it. The front part of the top piece has a “fin” , which is to redirect objects floating on top of the water from hitting the device head on and getting caught on something. It will also help mitigate the drag caused by the device from the flowing water. The bottom part of the device will be made out of a very dense material so that it will sink and extend the tubes once in water - either to the 3 foot max or the depth that the river allows. The top and bottom piece will house the magnets and coils needed to generate electricity from the oscillating tubes. They will also be connected via collapsible rectangular posts that remain stationary at each of the 4 corners. This ensures that the body of the device is supported and will remain stationary while the tubes are free to move along the tracks. Both platforms are 3 feet by 3 feet and are 3 inches thick.
Conceptual Design 2: Floating Design
The second concept above focuses on the need for portability as well as application in varied setup environments. Like some of the other designs, this concept uses cylindrical rods as “bluff bodies” to disrupt flow and create vortex induced vibrations, which in turn subjects the rods to lift forces, causing them to oscillate and generate electricity. In order for these VIVs to occur, the fluid flow must be normal to the surface of the cylinders, so it is crucial to have the device oriented in the correct manner. It is also important to note that users may be implementing the device in different bodies of water, which can vary in depth, floor composition, flow speed, flow direction and surrounding environment. This buoyant design addresses these concerns with several design features.
To allow for adaptability between environments, this concept is designed to float on the water's surface rather than rely on mounting to the floor. This is achieved with 4 buoyant panels that are connected to the top of the device. Hinges are incorporated on the bottom edge of each of the panels so that they can fold down for storage purposes. Once the device is placed in water, the panels lift up due to buoyant forces and the fin-shaped side walls force the device to orient correctly with the current. This feature allows users to implement the device in steady flowing currents and in currents that change due to tide or wind. The anchoring line attached to the carrying handle incorporates a swivel joint with three degrees of freedom so that the device can rotate freely into the correct orientation without the line getting twisted or tangled. The 3 degrees of freedom also enables the device to freely rotate when tethered to an elevated surface (such as a pier) or a ground surface (such as a dock cleat).
The internal electrical components are encased in a waterproof housing with a latch so that the user can open and remove the battery once fully charged. Incorporated in the housing is an LED charge meter to show the user if the device has reached appropriate charge. Four cylinder rods oscillate up and down on springs to generate electricity through magnets and coils, which are housed within the side walls. The electricity generated is converted to DC and stored in the battery. This adds an extra component as compared to a direct feed line but enables more versatility since the user may not have a source to connect the feed line to. Overall, this concept is similar to others in the way it generates electricity but is unique due to its versatility and ease of use.
Conceptual Design 3: Standing Design
As seen in the figure above, concept design three utilizes horizontal tubes in the same fashion as the second design, yet differs in its power generation method. In this design, the vertical supports act as the generator and are wrapped with copper coils which energize as the horizontal tubes push magnets up and down around them. On the top platform, the coils are wired to a DC battery circuit to store the produced electricity. While this design replaces the need for a top mounted DC alternator, it comes with its own series of setbacks. A main challenge associated with this design is determining a way to keep the coil and magnet system dry while below the waterline. With the top mounted DC alternator seen in concept two, waterproofing the vertical supports is not a concern as there are no electrical components submerged in the water. Additionally, a manufactured alternator may produce electricity with a higher level of efficiency than a coil wound by hand as concept three calls for.