Author(s): Patrick Donega Queiroz; Joao Lucas Dozzi Dantas; Felipe Santos De Castro; Felipe Araujo Da Mata; Gabriel Galvao Matos; Andre Mitsuo Kogishi

Linked Author(s): Felipe Santos de Castro, Gabriel Galvão Matos

Keywords: CFD; FEM; MATLAB; Numerical Tool; River Cleaning

Abstract: The development of society depends strongly on energy generation and, because of that, is not uncommon, mostly in Brazil, the installation of small hydroelectric power plants in rivers close to urban areas. The increase in energy availability promotes the occupation of space by people, intensifying pollution of these bodies of water, which is harmful in several aspects. In rivers with such plants, the debris presence interferes with their operation, reducing efficiency, time gap between maintenances, and causing damage of expensive structures installed. Given these issues, a system able to capture and remove great part of these debris from a river has been designed by the Institute for Technological Research, as part of an R&D project. The solution is composed by a floating structure close to the river central axis and trash boom lines, moored to this structure and margins, having the role of leading the floating debris to a conveyor belt, which takes them off water. To keep the floating structure in the designed position, mooring lines should be connected to the riverbed. The estimative of loads on both systems should be considered on the design phase. The present work has the objective to develop a numerical tool, based on MATLAB code, capable of calculating loads and the system final configuration. With a truss-based nonlinear FEM tool that calculates the load on the trash boom lines and, with the mooring coordinates and physical properties, all loads on the system and the floating structure displacement are iteratively calculated. For loads calculation in trash boom lines, the hydrodynamic coefficients of the modules composing the lines were calculated using the ANSYS FLUENT CFD tool. Given that the complete solver depends on the velocity field as an input, and that such velocity field varies with flow rate and water level, several hydrologic scenarios were calculated through numerical simulation using the software Delft3D. Different scenarios are simulated, providing valuable information on the system response to these velocity fluctuations. The tool has been used on project design phase, allowing a more suitable design of trash boom lines, mooring lines and the floating structure, given their interdependence. The numerical tool development not only benefited the present work, but will also be available to future similar projects and it can be improved along the way.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221143

Year: 2022