Modelo numérico para cálculo de transitório hidráulico com separação de coluna e interação fluido-estrutura

Abstract

Pump power failure, sudden valve actions, and the operation of automatic control systems are all capable of generating high pressure waves called hydraulic transients (HT). The severity of the phenomenon, as well as the damage caused, can be such that this becomes a point of attention in fluid transport projects. This work deals with the study of the phenomenon and the development of a numerical computational code, of HT with fluid-structure interaction (FSI) and column separation (CS) in one dimension in fluid transport piping systems. The FSI model was considered as a problem of initial and boundary conditions, represented by a system of hyperbolic partial differential equations that simultaneously describe the propagation of pressure waves in the liquid and of axial force waves in the structure. Column separation is treated as a boundary condition. The method of characteristics (MOC), associated with linear interpolations, was used to solve the system of hyperbolic partial differential equations. The proposed numerical model was validated with experimental data based on the article (BERGANT, ANTON et al., 2005) provided by author. for a system consisting of a reservoir with constant level at upstream with a single, straight pipe and a rigidly fixed downstream coupled valve. The one-dimensional numerical model (1D) based on mathematical formulations proposed by (TIJSSELING, 1993) and (BERGANT, ANTON et al., 2008) was implemented in the Python® language to analyze FSI and column separation in a reservoir-pipe-valve system.