Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Validation of a CFD code with LBM approach with experimental data from a Tesla turbine
Submission Author:
José Filipe Trilha de Carvalho , RS , Brazil
Co-Authors:
José Filipe Trilha de Carvalho, Paulo Smith Schneider
Presenter: José Filipe Trilha de Carvalho
doi://10.26678/ABCM.ENCIT2022.CIT22-0477
Abstract
Tesla turbines are equipment used mainly in the generation of electric energy. In these turbines, the internal discs rotate due to the friction caused by the contact with the working fluid, hence generating power. Another characteristic of these turbines is the sonic flow, developed when the fluid get out of the convergent nozzle. for the design of a Tesla turbine in order to reach a satisfactory operation. In this context, this paper presents an analysis of a Tesla turbine subjected to various inlet pressures. A comparison with experimental existing data was performed to calibrate the numerical approaches used. The Tesla turbine prototype was composed by a volute, the convergent nozzle, and rotor discs in a shaft. Simulations of the air flow inside the turbine were conducted using the computational fluid dynamics (CFD) technique, considering the Lattice Boltzmann method (LBM). The aim was to evaluate the characteristics of the flow, such as the pressure and velocity profiles, developed in the single-phase flow. To determine the inherent error due to the mesh refinement in the CFD study, three different sizes of the Lattice grid were considered. The Mach number was checked in the model, regions with a Mach number of 1 were observed, confirming the presence of a compressible flow, in which compressibility effects can not be disregarded. The Reynolds number obtained through experiments agrees well with the literature, indicating the occurrence of a turbulent flow. Simulated results enabled to estimate the performance of the Tesla turbine. The torque results of the prototype were compared against experimental results, in the same Pressure and mass flow intervals, with a variation in relation to the physical experiments in Tesla turbine prototype ranging from 4 % to 9 % using a configuration with only one disk.
Keywords
tesla, CFD, LBM, Turbine
