Abstract: Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. While a turbine transfers energy from a fluid to a rotor, a compressor transfers energy from a rotor to a fluid. Many different designs of turbomachines are in use of which Tesla turbomachine is one, whose design is different from conventional designs. A Tesla turbomachine utilizes the viscous shear forces of a fluid (boundary layer effect) passing near a disk on an axle to transmit torque to and from the fluid. Tesla turbomachines have found wide ranging applications that include handling of mixtures of solids, liquids and gases without damaging the machine. It can be designed to efficiently pump highly viscous fluids as well as low viscous fluids. It has been used to pump fluids including ethylene glycol, fly ash, blood, rocks, live fish and many other substances. This paper attempts to present the outcomes of research carried out by various researchers during the last four decades. A summary of the modeling, simulation, and experimental procedures used to understand Tesla machines is presented. The performance of Tesla machines is found to be influenced by a number of parameters including width of disks, the number of disks, gap between disks, jet angle at inlet, inlet pressure, load applied, Mach number, Reynolds number. The paper also outlines the results of investigations performed by the researchers and further identifies the deficiencies, which can serve as a future direction to research in this field.
Keywords: Turbomachine, viscous forces, boundary layer effect, Mach number, Reynolds number