Avaliação de modelos de atrito variável em transientes hidráulicos

Abstract

The purpose of this paper is establish a comparison between two unsteady friction models, the Brunone et al.’s model (1991) and the Vardy et al.’s model (1993), and the elastic model, in order to identify the most appropriate approach for description of hydraulic transient in valve closure scenarios. For this, a computational routine was developed to simulate the models. In this simulator the parameter values of the variable friction models were defined. For the Brunone et al.’s model (1991), were used the equations of Brunone and Karney (1999) and of Vardy and Brown (1996), for their decay coefficient. For the Vardy et al.’s model (1993) calibrated parameters by the authors were used. The models were evaluated by experimental data extracted of the researches of Pezzinga and Scandura (1995) and of Bergant and Simpson (1994), who conducted experiments in the Reservoir-Pipe-Valve systems with transient generated by a valve closure. The Brunone et al.’s model (1991), with a damping coefficient given by Karney and Brunone (1999) describe with better precision the effects of attenuation of the pressure wave.