Simulation Based Design of a Bladeless Centrifugal Flow Compressor
The bladeless centripetal flow turbomachinery or disc turbine was invented by Nikola Tesla with the aim to realize a turbine with higher efficiency and simplicity compared to the state of the art at that time. Unlike conventional turbines, the disc turbine does not use rotor blades. Instead, it consists of a series of thin discs arranged on a common shaft. By changing the principles’ direction, a bladeless centrifugal flow compressor can be realized. The function if such a compressor is based on the principle friction between two rotating discs and the fluid. The rotation of the disc is realized by applying an electric drive and the working fluid gets accelerated in a narrow gap between the discs towards the outer edge. This results in the increase of the fluids velocity at the outer diameter of the discs, leading to a compression effect. In this work, a simulation based concept design for a bladeless centrifugal flow compressor is presented. Based on two different promising materials, structural mechanics simulations using the Structural Mechanics Module were performed to derive the interactions between the rotational speed, the disc diameter and the mechanical loads. In a subsequent simulation model, fluid-dynamic parameters such as the pressure rise were calculated by using the CFD Module and evaluated on the basis of the maximum possible rotation speed while varying other relevant design parameters such as the gap width and disc diameter. As one example, it could be shown that the disc diameter and rotation speed have an significant impact on the fluid-dynamic parameters. Finally, a basic functional design for a bladeless centrifugal flow compressor/compressor could be derived based on the simulation results.