The project researches how underwater turbines perform in laminar flows when tubercles of varying orientations are applied to the leading edge of each turbine blade. Research was done into how the flow of the current will be analyzed and how performance from the turbine will be determined. Reynolds numbers calculations will have to be made to ensure that the flow is laminar; the equation for determining the turbulence of the liquid or gaseous flows is (Density* Velocity*Length)/(Pascals*sec). Turbulent flow is very fast and disturbed, typically characterized by bubbling in the flow and vortices. Laminar flow is slow, smooth and undisturbed, typically characterized by clear water and no vortices. Laminar flow is the flow trying to be achieved, this is because research is being done to improve turbine performance in lower velocity waters. Laminar flow has the property of fixing itself within two to three radii of the initial disturbance, in this case, the turbine blade's foil striking the flow. Hopefully, the tubercles being applied do not produce vortices and increase the turbulence relative to a blade with no tubercles.
Performance of the turbine will be determined by utilizing ohms law. The law states that an electrical flow under a load produces wattage dependent on the load, in ohms, and the voltage being produced by the power source (in this case, the turbine). Therefore, if the turbine is placed in a consistently laminar flow, and a controlled load is applied, a specific voltage will be produced by the turbine depending on the torque applied by the turbine blade. Varying loads can also be applied to simulate varying velocities and produce a power curve. A power curve is a chart that displays power in wattage along the x-axis and velocities across the y-axis, so that performance of the turbine blades can be compared at varying velocities to find the truly optimal design. So, if the loads are controlled and the flow is controlled, voltages produced by the turbine will be measured to determine how well the turbine blade is transforming kinetic energy from the current into electrical power under the specified loads. Ultimately, this allows for quick, efficient and highly controlled tests that give a good idea of performance across different situations.
Finally, the turbulence generated by altering the leading edge of the turbine blade will be examined by placing grids behind and in front of the laminar flow. The grids will had strings attached to them to map how the water is moving after hitting the blade. If the disruptions experienced do not dissipate within 3 radii of having stricken the blades surface, then a notable increase in turbulence can be examined to determine environmental impact.
Materials for construction:
Alumilite Silicon Mold and Polyeurathane Resin Kits
PVC tubing
Stuffing box (homemade)
PMG generator