Cavitation flow pulsation mechanism of axial high-pressure plunger pump in the sea water desalination system

Numerical simulations and analyses were conducted through the comparison of Full Gas Model and the compressibility model with the multi-factor theoretical flow control equation. The physical mechanism of cavitation in the axial plunger pump of the seawater desalination system was revealed under the influence of “water hammer effect”. The cavitation flow was compared with the theoretical flow to screen out the factors that affect the flow pulsation. Influenced by the water hammer effect, the gas-phase volume fraction of the plunger chamber in the water suction area at the critical angle of 90° increased first and then decreased, which validated Kollek’s experiments (Kollek et al. in Arch Civil Mech Eng 7:61–73, 2007). The water hammer effect at the top of the plunger chamber had the largest pressure peak. The multi-factor theoretical flow control equation and flow pulsation characterization equation were proposed, and the cavitation flow pulsation of the axial plunger pump was much bigger than the theoretical flow pulsation. It was found that the cavitation and backflow of the plunger chamber are the two most important factors for the lack of flow in the axial plunger pump. This paper provided important guiding value for the design of seawater axial plunger pumps.