Cavitating flow through a Venturi using CFD: effects of inlet and outlet pressures

Hydrodynamic cavitation is a complex physical phenomenon that appeared in hydraulic systems (pumps, turbines, valves, Venturi tubes …etc.) when the fluid pressure decreases below the saturated vapor pressure. The works carried out in this study aimed to get a better understanding of the cavitating flow phenomenon. For this, we have numerically studied a cavitating bubbly flow through a venturi nozzle. The cavitation model is selected and solved using commercial code computational fluid dynamics (CFD). The numerical results are compared to the previous experimental and numerical data.The obtained results showed that the effect of the inlet pressure (10, 7, 5 and 2 bars) and outlet pressures (6.5, 6, 5, 4, 3.5, 1.5, and 1 bars) of the Venturi on pressure, velocity of the fluid flow and the vapor fraction formation. We found that the inlet and outlet pressures of the venturi are strongly affected on the evolution of the pressure, velocity and vapor fraction formation in the cavitating flow. The results presented in this study provide insight and useful guidance to the designer of hydrodynamic cavitation devices, identifying key geometrical and physical parameters of cavitation onset and intensification that can be manipulated to achieve the desired level of cavitation flow.