Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Francis Generating Unit Modelling Through High-fidelity CFD Simulations
Submission Author:
Leandro Jose Lemes Stival , PR
Co-Authors:
Leandro Jose Lemes Stival, Leonardo Sicchieri, João Marcelo Vedovotto, Aldemir Ap Cavalini Jr
Presenter: Leandro Jose Lemes Stival
doi://10.26678/ABCM.COBEM2023.COB2023-0081
Abstract
The development of Computational Fluid Dynamics (CFD) has expanded to problem application complexes involving fluid-structure interaction. Numerical modeling has been used in energy projects to solve the properties of turbulent flows in detail. In particular, the use of Large Eddy Simulation (LES) has increased for rotor simulations due to the increased computational power available. Because of that, the application of LES by renewable energy research groups is increasing and stimulating the evolution of the methodology. LES is based on a spatial filtering process of the governing equations, which allows an explicitly solution to the largest turbulent structures on computational meshes and to model only the smallest scales. This method, in conjunction with the Immersed Boundary (IB) method, is the state-of-the-art approach to simulate flows with high Reynolds numbers, with fluid-structure interactions involving complex and moving geometries. The approach is known as immersed type methods, in which the immersed boundary method (IB) is a classical example. The IB method arose as a strong and effective simulation tool for dealing with complex flows, because of its capacity to take care of complex structures without the need for expensive and complicated dynamic meshing techniques. Due to the meshing flexibility, the IB approach has acquired significant popularity over the past two decades for several problems, especially for heavy movements in solids or large deformation in the fluid. In this article, the results of three-dimensional simulations of the complete system will be presented, considering the flow through the spiral case and the rotor (Francis turbine) in motion. Thus, the concepts involved in the mathematical formulation over a generating unit virtual machine (UG). Moreover, details about the mechanical, electrical, and hydraulic forces that act on the system and a previous sensitivity analysis will be presented to demonstrate the development of an innovative project on the dynamic responses of a UG. In the simulations, the rotor and the upstream and downstream flow will be instrumented with virtual pressure and velocity probes to evaluate the intensity of turbulence and determine information such as emission frequencies and vortex passage in specific regions of interest. The numerical framework used in the simulations performs LES under a Cartesian block-structured mesh that is dynam ically refined via an adaptive mesh.
Keywords
Large Eddy Simulation, Francis Turbine, Immersed Boundary Method, Adaptive mesh refinement
