As I understand it, a tesla turbine runs by injecting steam, or some other gas onto the outside of several disks mounted parallel to each other on a shaft. The gas is directed roughly tangent to the outside of the disks and it exits through openings in the center of the disks. Seems straight forward and all, but somewhat counter intuitive that expanding steam/air/whatever has to squeeze into a smaller space as it migrates towards the center. If it speeds up to compensate for the smaller space, it is 'fighting' against a slower turning surface towards the center of the disks. - I have thought about a similar turbine but instead of having preheated steam injected at the outside the whole disk assembly is heated to the point that it will boil water injected at the center. The steam that is boiled off after hitting the hot disks will not do a whole lot as I have described it so far. What I envision is having 'stators' between each disk. These stators would be spiral shaped from the center out to direct the steam in a manner to cause the disks to turn from the friction of the steam against them. The stators would be shaped in a way to take advantage of the steams expanding volume as it migrates towards the outside. Functionally doing the same thing that a conventional steam turbines stator and rotor blades do by changing shape to take advantage of expanded steam as it gets closer to the exhaust. As for sealing between the stator and rotor? So far my only idea is simply a close fit that does not contact. Efficiency may be ridiculously low, but I just am wondering about concept. - Am I missing something in a conventional tesla turbine? I see reports of efficiencies that are all over the place but you cannot really believe what you read on Nikola Tesla since there are alot of nut-cases out there that worship anything connected to him.