The Tesla turbine is a bladeless centripetal flow turbine patented by Nikola Tesla in 1913. It is referred to as a "bladeless turbine". The Tesla turbine, also known as the boundary-layer turbine, cohesion-type turbine, and Prandtl-layer turbine, (after Ludwig Prandtl) uses the boundary-layer effect instead of a fluid upon the blades as with a conventional turbine. Bioengineering researchers have referred to it as a multiple-disk centrifugal pump. One of Tesla's desired implementations of this turbine was for geothermal power, which he described in his work Our Future Motive Power. Theory In standard steam turbines, the steam has to press on the blades for the rotor to extract energy from the speed of the steam, due to the difference between the relative speed of the steam and the blades. 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. In their words, in the optimal regime, the orientation of the blades is trying to minimize the angle (blade pitch) with which the steam is hitting their surface area, as to create smooth steam flow, to try to minimize turbulence. These eddies are created in reaction to the steam impacting (although the minimized angle in the optimal turbine speed) the surface of the blades. In this dynamic, the first eddies a loss of the useful energy that can be extracted from the system, and second, as they are in opposite directions, they subtract from the energy of the incoming steam flow. In the Tesla turbine, considering that there are no blades to be impacted, the mechanics of the reaction forces are different. The reaction force to the steam head pressure builds relatively quickly, as a steam pressure "belt" along the periphery of the turbine. That belt is most dense, and pressurized, in the periphery as its pressure, when the rotor is not under load, will be not much less than the (incoming) steam pressure. In a normal operational mode, that peripheral pressure, as Tesla noted, plays a role of BEMF (Back Electromotive Force), limiting the flow of the incoming stream, and in this way, the Tesla turbine can be said to be self-governing. When the rotor is not under load the relative speeds between the "steam compressed spirals" (SCS, the steam spirally rotating between the disks) and the disks are