Annular Tesla turbine

The invention provides an annular Tesla turbine. A rotor of the ring-shaped Tesla turbine is made into a circular ring; a stator is arranged inside the rotor; the stator has bigger diameter at one end and smaller diameter at the other end; the bigger end of the stator is provided with a spray nozzle; the smaller end of the stator and the rotor have a bigger gap to form an exhaust port; annular thin sheets are fully distributed at the internal side of the rotor; the annular thin sheets close to the spray nozzle have small gaps and the annular thin sheets close to the exhaust port have big gaps; the spray nozzle injects the air toward the rotor along the tangent line direction of the circular ring; an airflow can form a vortex flow under the guide action of the internal side of the circular ring and drive the circular ring to rotate together, so that the rotation of the rotor is realized. The annular Tesla turbine disclosed by the invention can replace a thin circular tray of the traditional Tesla turbine by using the annular thin sheets at the internal side of the circular ring; the annular thin sheets can be integrated with the circular ring into a whole or are supported and fixed from the ring, the rigidity of the annular thin sheets is better than that of the thin circular tray, and the thin sheets are not easy to deform, so that the diameter of the rotor can be bigger and rotor are not easy to deform, accordingly, the power is increased, the efficiency is improved and the operation process is stable and reliable.