Numerical Analysis of Cavitation Development in a Single-Blade Slurry Pump

Abstract

Cavitation is a harmful phenomenon in pumps, as it can cause performance degradation, pressure pulsations, vibration and erosion damage. Single-blade slurry pumps are commonly used for transporting wastewater, slurry and liquids containing solid or fibrous particles due to their high passage capability and reduced risk of clogging. In this study, cavitation development in a single-blade slurry pump was investigated using CFD. The numerical model was created in ANSYS CFX and included the complete hydraulic domain of the pump. Cavitation was modelled using the Zwart-Gerber-Belamri model and turbulence was described by the SST k-ω model. The simulations were performed at a fixed flow rate and decreasing inlet absolute pressure. The results were analysed for three inlet absolute pressures: 70 kPa, 35 kPa and 19.5 kPa. Vapour-dominated regions were identified using the criterion of water vapour volume fraction α v > 0.5. The results showed that decreasing inlet pressure led to a substantial increase in cavitation extent. The mean volume of the vapour-dominated region increased from 2.83×10 −6 m 3 at 70 kPa to 1.33×10 −4 m 3 at 19.5 kPa. The pressure fields confirmed that vapour formation occurred in regions of reduced absolute pressure.