Study and dimensioning of a Tesla turbine using computational tools

• Autor(a) principal: Simões, João Henrique Bernardo
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/30393
• topic: Tesla turbine; Computational fluid dynamics; Power conversion; Numerical simulation; Thermodynamics; ANSYS/Fluent

The Tesla turbine was invented in the beginning of the XX century but only after almost a century the scientific community began to show some interest for this Nikola Tesla invention. The Tesla turbine sets itself apart from other turbines by the fact that it has discs instead of blades. The mechanisms by which this turbine can generate power from a flow is unique, the available torque is a result of the viscous forces exerted by the fluid on the discs. The purpose of this dissertation is to study the Tesla turbine and analyze its performance under different configurations in order to develop a better understanding on how a Tesla turbine can be designed to promote power output. The Tesla turbine is tested with methane as the working fluid and fixed inlet and outlet pressures (60 and 30 bar respectively). In this dissertation, a parametric study is presented using computational fluid dynamic (CFD) tools. A 3D model of the turbine was developed. The model was meshed, and the mesh was tested and validated using mesh independence test and Richardson extrapolation method. Energy and turbulence models were selected, and the fluid was defined as a real gas through the Redlich-Kwong equation of state. Proper solution methods were selected, and different runs were performed. The Tesla turbine was tested with different values for the disc diameter, the inter-disc gaps, the rotor angular velocities and the number of discs. From this study it is concluded that the turbine generates more power with large discs. When the diameter of a disc is increased, its angular velocity should decrease to promote power. The mass flow rate increases as the angular velocity decreases. Thin inter-disc gaps perform better for small discs at low angular velocities while for large discs or high angular velocities thicker disc gaps are recommended.