DRG presentation at Pressure Surges Dublin

25 Aug 2015

New cavitation experiments compared with surge analysis software BOSfluids and Wanda

The presentation describes the comparison of cavitation experiments with numerical results obtained with the pressure surge analysis software BOSfluids®. Together with Deltares, Dynaflow Research Group has conducted a series of experiments using the Deltares Alpha Loop. The Alpha Loop is a recently commissioned multiphase flow loop (DN200 PN16).

The focus of this series has been the generation of cavitation and column separation to extend the validation experience by using the cavitation modules of numerical surge analysis software packages like BOSfluids® (DRG) and Wanda® (Deltares). The amount of generated cavitation is varied by means of a fast closing flow control valve.

The experimental results are compared to the numerical results obtained by means of a transient analysis, with the additional option to simulate cavitation and column separation using several numerical models such as the Concentrated Air Pocket method and the Vapor Cavity Model. When the pressure in a line drops to the vapor pressure a portion of the liquid will vaporize. This can lead to situations where voids of gas form between fluid columns. When the pressure recovers (rises again above the vapor pressure) these fluid columns may collide with each other creating pressure waves traveling through the system. The results of the experiments are compared with the BOSfluids® and Wanda® results for different valve closure times.