Aiming at the cavitation phenomenon of valve port in the flow distribution process of ball valve,a 3D computational fluid dynamics model of the flow domain was established.The Zwart-Gerber-Belamri cavitation model and the renormalization group κ-ε turbulence model with turbulence viscosity correction were integrated to numerically simulate the cavitation phenomenon.In a typical condition,volume fraction contours and gas iso-surface were used to reveal the periodic evolution of cavitation intensity and bubble shape near the valve port.Relevant flow characteristics in this process were elucidated by analyzing the velocity and pressure fields.Additionally,the influences of valve opening,inlet pressure and back pressure on cavitation flow field were also investigated.The results show that the cavitation characteristics in the ball valve are affected by its opening.As the opening increases,the cavitation range and intensity decrease,and the periodic evolution of the cavitation flow disappears when the opening exceeds 0.3 mm.Increasing back pressure prevents the cavitation tail from extending towards the outlet,reducing both the cavitation range and the frequency of the flow evolution.Higher inlet pressure accelerates the initial formation of cavitation at the valve port.However,after the opening exceeds 0.4 mm,the inlet pressure seldom affects the cavitation intensity.