Tesla turbine

The Tesla turbine is a bladeless centripetal flow turbine patented by Nikola Tesla in 1913. It was his 100th patent. Nozzles apply a moving fluid to the edges of a set of discs. The engine used smooth discs rotating in a chamber to generate rotational movement due to the exchange of momentum between the fluid and the discs. The discs were arranged in an orientation similar to a stack of CD's on a pole. The Tesla turbine uses the boundary-layer effect, instead of the method employed by more conventional turbines, wherein fluid turns the blades. The Tesla turbine is also referred to as the: Bladeless turbine, boundary-layer turbine, cohesion-type turbine, and Prandtl-layer turbine. The latter of these names is after Ludwig Prandtl. Bioengineering researchers have additionally referred to the Tesla turbine as a multiple-disk centrifugal pump. One of Tesla's intended implementations for this turbine was for the generation of geothermal power, which he described in his work Our Future Motive Power. In the pump, the radial or static pressure, due to centrifugal force, is added to the tangential or dynamic (pressure), thus increasing the effective head and assisting in the expulsion of the fluid. In the motor, on the contrary, the first named pressure, being opposed to that of the supply, reduces the effective head and the velocity of radial flow towards the center. Again, the propelled machine a great torque is always desirable, this calling for an increased number of disks and smaller distance of separation, while in the propelling machine, for numerous economic reasons, the rotary effort should be the smallest and the speed the greatest practicable. In standard steam turbines, the steam has to press on the blades for the rotor to extract (kinetic) energy from the steam. In the bladed steam turbine, the blades must be carefully oriented in the optimal speed regime of the turbine's work, as to minimize the angle of attack to the blade surface area.