Numerical Analysis on Cavitation Erosion of a High Pressure Differential Control Valve
The numerical simulation on the cavitation erosion of a high pressure differential control valve is conducted. The characteristic of cavitation flow is obtained by using full cavitation model and RNG k-ε turbulence model with actual operational conditions and fluid physical parameters. Results showed that: the flow velocity increases rapidly as the fluid passes through the gap between the valve spool and seat. Simultaneously the local static pressure decreases below the saturation pressure of the fluid, then the cavitation is formed. For the convergent - expansion structure, the flow separation occurs due to the pressure recovery, which leads to the formation of recirculation zone, where the cavitation cloud appears. The increases of fluid temperature and inlet pressure or the decreases of valve spool angle and valve opening result in the enlargement of cavitation area and enhancement of cavitation intensity. The numerical simulation results correlate well with actual failure morphologies, which proves that the method can be successfully applied in the cavitation prediction of a high pressure differential control valve.