Desenvolvimento de modelo computacional para simulação de transiente hidráulico em linhas de recalque

Abstract

The phenomenon of hydraulic transient, also known as water hammer, can cause serious problems in hydraulic installations as well as disturbances to public supply. The underpressures and overpressures resulting from the sudden closing of valves or interruption of pumping can cause damage to hydraulic installations, hence the need to know the magnitudes of these events. Thus and so, the objective of this dissertation was to develop a computational model to calculate the pressures resulting from the hydraulic transient in settlement lines, using the Characteristics Method, based on models generated by the Epanet software. The computational model was written in Visual Basic language under the Visual Studio 2010 platform. The results obtained from the simulations were compared with the pressure load data measured in a 1606.00m extension line, 350mm diameter in Cast Iron, and with a manometric height of about 50 mH2O. The pressure profiles simulated over time next to the check valve resulted in adherence to the values measured in the field, mainly in the first period of the pressure curve. The results simulated by the developed model were corroborated when compared with the results obtained with the Allievi ® software. The amplitudes observed in the first period of the pressure waves were compatible with the theoretical predictions obtained by the Jouguet Equation. The computational model developed also simulated the pump stop condition by setting a voltage ramp to slow down the pumping. The simulation results were compared with the data measured in the field and did not result in good adherence.