Estudio de mallado estructurado 3D rotativo en OpenFOAM para aplicaciones en turbinas tipo Francis

Abstract

The development of a methodology to study Francis turbines using the open source CFD software OpenFOAM along with a multiple reference frame and a structured moving mesh for steady and unsteady state cases respectively, was carried out in this research work. OpenFOAM offers clear advantages over others CFD packages, such as a better parallel calculation process, low cost, better control of simulation parameters and optimization of computational resources. The structured mesh used was obtained from previous studies, nevertheless, some modifications were done due to the presence of imbalance points in the numerical simulation. Two types of numerical simulations were performed together with turbulence models k-ε and k-ω SST, first using the SIMPLE algorithm for steady state cases, and the PISO + SIMPLE (PIMPLE) algorithm for unsteady state cases. The results obtained for the steady state simulations reproduce the phenomenon with a great approximation. Ten different operating points were studied in the steady state simulations, obtaining an error of 5.02% for the power when using the maximum value of flow. Due to the one revolution approach of the unsteady state simulations, the phenomenon was partially captured.