Alternative energy production is an important part of our future energy resources. Every effort to optimize efficiency is needed to meet the goal set by the president during the 2011 State of the Union Address of nationally consuming 80% clean energy by 2035.
After researching common water turbine designs, I found that the traditional designs are largely semi-submersed and consequently unable to be used in many situations. These situations include the capturing of ocean currents, for example, or for areas such as third world countries where it might be cost-prohibitive to build a dam. I considered that these problems would be alleviated and hydro-turbines would become more economical if they were able to work completely submersed under water, and could also be more efficient.
I decided that to make a turbine be able to work while being completely submersed, the fin on a turbine would have to change to be a different shape when going with the water than going against the water flow. To make the fins of a turbine change, I decided to rotate them. In this way, I came up with the idea of a fin as a sail. And by mathematically testing a range of angles and their corresponding theoretical torque, I discovered a surprising gear ratio that theoretically delivers the optimum efficiency.
To test this design, I built a scale model out of household supplies. I also built a control model using a traditional fixed fin design of the same size. I tested these turbines at the University of Minnesota, St. Anthony Falls Laboratory (SAFL) using their 20 inch flume. I measured the power produced by each turbine using a motor attached to the turbine above the water. I used the following experimental variables:
Independent Variables: Turbine Design and Method for Energy Harvesting
Dependent Variable: Power = Voltage2/Resistance
Based on the comparative data collected, I concluded that the new alternative water turbine would provide a viable option for increased energy collection and could expand the opportunities for extracting hydroelectric power.