An advanced CFD model to study the effect of non-condensable gas on cavitation in positive displacement pumps

An advanced transient CFD model of a positive displacement reciprocating pump was created to study its behavior and performance in cavitating conditions throughout the inlet stroke. The “full” cavitation model developed by Singhal et al. was utilized and a sensitivity analysis test on two amounts (1.5 and 15 parts per million) air mass fraction content was carried out to study the influence of the air content in water on the cavitation phenomenon. The model was equipped with user defined functions to introduce the liquid compressibility which stabilizes the simulation and to handle the two-way coupling between the pressure field and the inlet valve lift history. Estimation of the pump performance is also presented in both cases