Study of a Tesla turbine efficiency and performance

Abstract

Since its invention, the Tesla turbine has had little industrial application and relatively few investigations have been carried out in order to achieve a machine which can be very useful in some fields where other machines have difficulties. Nowadays, the available technology permits to build this sort of turbine in a way which was not possible in 1913. Since recently, the interest on the Tesla’s first design has grown and new experimentations have been started and performed. It is the goal of this study to run tests on a functioning Tesla Turbine provided by the ITSM at the Stuttgart University in order to learn about its performance and to reach conclusions about the efficiency and power of this model. Basically, the constructive parameter inlet nozzle diameter has been modified twice in order to determine its impact on the turbine’s functioning and experimental results, which are presented in this study. Prior to the experiments, some modifications have been done to the test stand, in order to adapt it to the current necessities of this study: improvement of the needle for the lever to increase accuracy in the measurement of the weight, substitution of old bearings for new and improved ones for the turbine and the DC dynamo, connection of two thermocouples and a universal transmitter in order to be able to record the temperature difference between inlet and outlet of the turbine so that the enthalpies and the isentropic efficiency can be calculated, implementation of a new measuring protocol for the balance, integration of a fourth power resistor in order to achieve lower loads, improvement of the device for the dissipation of the turbine output power by means of a ventilation directed to the power resistors and an integration of a metal plate to avoid overheating, calibration of the revolutions, the mass flow rate and the pressure and adaptation of all the changes to the existing data acquisition software.