The Tesla Turbine
The Tesla Turbine is a sort of bladeless turbine. A Tesla turbine is a type of turbine invented by Nikola Tesla in the early 20th century. As it is a series of flat disks aligned on a shaft that work by the effect of the boundary layer or fluid moving across the flat disc.
In a Turbine, you have a series of a flat disc with a very thin disc gap between them. The thin gap maximized the boundary layer and minimized the fluid flow around the boundary layer.
In a traditional Turbine from the front side, you have a series of blades. If you are looking from the side, you have a series of blades mounted along the shaft. So in the traditional turbine, the fluid flows across the blades, causing them to rotate around.
The Tesla Turbine instead uses a series of flat disks and with slots or holes in the center. Moreover, there is an inlet that fires a fluid towards the edge of the disk.
Working
So as the fluid moves across the disk due to the boundary layer effect. It clings the disk and causes the disc rotating transfers the kinetic energy that the fluid has to the disk causing to rotate a torque. As the disk rotates faster and faster, the air starts to spiral around the disk towards the center.
Once you get to a point, where the angular velocity is very great then you have a tight spiral that goes straight to the center and that where you experience high efficiencies in the Tesla turbine.
Improved Tesla turbine
In most traditional turbines, there are some problems that they have. As they can only be run in one way. Basically, you cannot reverse the direction of a traditional turbine. Moreover in a Traditional turbine, there are a series of machines blades and generally, when something breaks on the turbine, the entire thing has to be taken off.
Moreover, you have to machine a blade or part of the blade back on to there which is costly and time-consuming. In Tesla’s turbine, when you have a series of flat disks.
Disks are much easier to produce. Moreover, you have a series of slot or a series of holes in the center. As it’s a lot simpler to design, that is why it is used by scientists who like to experiment with this turbine.
Most modern turbines have the theoretical efficiencies of above 90%. When Tesla originally designed his turbine, he theoretically predicted that one could have the efficiencies of 97%.