A turbine is a rotary engine that extracts energy from fluid or air flow and converts it into useful work. The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving air or fluid acts on the blades, or the blades react to the flow, so that they move and impart rotational en
The new Fuller turbine is actually based on a century old design, the Tesla steam turbine, a bladeless centripetal flow turbine patented by Nikola Tesla in 1913. The original turbine used the boundary layer effect in order to distort surrounding nonviscous flow or air. Now, it is being used once more for the same purpose, but since engineering has evolved during the last 100 years, so has the design of the turbine.
Howard Fuller (who named the new turbine), explained the mechanics behind the new turbine: “Closely-spaced discs trap the motive fluid molecules (in this case air) in a laminar flow adjacent to the disc surface. This provides aerodynamic drag, which imparts force to the disc surface. By using multiple discs, the turbine then provides considerable torque to accelerate the rotation of the central driveshaft, which is directly coupled to an alternator, typically located at the base of a tower, or alternatively co-located on a rooftop.”
The major benefits of this technology are less noise, reduced radar interference (making vehicles that use this kind of turbine to be practically invisible to most radar), minimal visual pollution, and zero wildlife injuries, thanks to the absence of sharp rotating metal blades.
Currently the turbine is only in its pre-prototype stage; however, Solar Aero anticipates that units will be available in different sizes. The smallest unit would be likely to produce about 5kW at 15 knots, and it is likely to have a cut-in speed of about 3.5 knots with optimum speed of approximately 20 knots. Moreover, its near-transparency to radar microwave transmissions is completely feasible, as long as the proper construction materials and techniques are implemented.
According to experts, the maintenance costs should be relatively cheap (comparing to coal-fired power generation). Estimations are that these costs should be around $0.05 per kWh. This is a good ratio even when compared to bladed turbines; since the up-tower turbine is supported solely on zero maintenance magnetic bearings, there will be no friction to impede acceleration and no routine lubrication required. When used in conjunction with a suitable energy storage device, this should provide reliable, inexpensive power in either residential or commercial applications.
TFOT has also covered the Swift Wind Turbine, the first quiet rooftop turbine that generates electricity by harnessing the power of the wind, and StatoilHydro’s Hywind, the world’s first full scale floating wind turbine. Another related TFOT story is HYmini, a handheld hybrid mini green power station which uses renewable wind power, solar power, and the conventional electric power outlet to provide constant power supply.
For more information about the bladeless turbine, see Solar Aero’s website.