Numerical study on the effects of air valve characteristics on pressure surges during pump trip in pumping systems with air entrainment

摘要

An improved numerical model and computational method are proposed here for the study of the effects of air valve characteristics on pressure surges during pump trip in fluid systems with air entrainment. Numerical experiments have shown that airvalves with higher inflow characteristics installed at peak locations of a fluid system may reduce the magnitude of the extreme negative pressure surges. However, for near zero air entrainment levels in the fluid system, air valves with higher outflowcharacteristics tend to result in higher positive pressure surges. The results of the numerical simulations seem to be in qualitative agreement with available field observations [T.S. Lee and H.F. Cheong, Teck Hock Pumping Station: Flow Rate and PressureTransient Measurements, Johnson Pacific, Singapore, 1994].