Influence of temperature on transient flow with cavitation in copper pipe-rig

This article is particularly interested in the numerical modeling of water hammer in a hydraulic circuit, taking into account the prevailing water temperature. The study concerns the propagation velocity of the wave and the amplitude of unsteady phenomena encountered in the circuit, as well as the severity and collapse of cavitations that are also considered as major risks. To conjecture the consequences of these phenomena, we were led to simulate a single-phase and two-phase transient flows in a hydraulic copper pipe system in a temperature range of 4-95 degrees C. To do this, we have developed a solver for the dynamic and continuity equations' resolution. The method of characteristics is chosen for its capacities to solve these equations. Its application shows that it is robust and adapted to the problem studied. Two cavitations' models and column separation have been incorporated; in this case, the Discrete Vapor Cavity Model (DVCM) and the Discrete Gas Cavity Model (DGCM). Moreover, in addition to the classic models of quasi-stable friction, of which the models of unsteady friction have been included, like the one based on the instantaneous acceleration proposed by Brunone and the one proposed by Vardy & Brown based on the convolution integral. Although single-phase and two-phase water hammers do not behave in the same way, the results obtained with these models show that the temperature produces a great effect on the hammer.