Enhanced Physically Based Models for Pressure Characteristics at Plunge Pool Bottoms

AbstractPredicting the characteristics of the dynamic pressures at plunge pool bottoms due to the impact of plunging jets is essential in designing and assessing the stability of lined or unlined plunge pool bottoms. In this article, by developing a large-scale physical model, the generated dynamic pressures at plunge pool bottoms are measured in different plunging jet conditions and pool water depths. The validity of the existing empirical formulations in predicting the dynamic pressure mean (CP) and pressure fluctuations (CP′) is assessed based on the experimental data. The comparison of the predicted results through existing empirical models with the observed experimental data indicates that the recently developed models have acceptable accuracy in predicting the CP coefficient, but not the CP′ coefficient. By running a parametric analysis through dimensional analysis, the dimensionless parameter of plunge pool Froude number [FrP=Vj/(gY)0.5, where, Vj = jet velocity at pool surface, g = acceleration due to gravity, and Y = plunge pool water depth] is introduced as an alternative to Y/Dj, (where, Dj is jet diameter at pool surface) to simultaneously consider the effects of pool water depth and jet velocity. The results indicate that at FrP≤2, the CP′ coefficient is negligible and = 0.10. At 2