Simulations of bubbly two-phase flow in hydraulic jumps of relatively high Reynolds number.

Hydraulic jumps on a large scale are turbulent, with high Reynolds number. It has been proven difficult to achieve this in previous studies of jumps as two-phase flow. This paper aims to investigate the behaviours of two-phase flow and air entrainment in jumps at relatively high Reynolds numbers. Model predictions of both oscillating and steady jumps at multiple values of Froude number are reported, along with verifications of the predictions using air volume fraction (AVF) measurements, and analytical and empirical solutions for the height of jump, roller length, and free surface. The model captures the macroscopic characters of the two types of jumps and velocity structures. The predicted AVF distributions are consistent with the velocity structures. For steady jumps, AVF profiles are roughly bell-shaped, but are heavier-tailed upward than downward. For oscillating jumps, AVF profiles are even more asymmetrical. The Reynolds number affects air entrainment and transport in two-phase flow. [ABSTRACT FROM AUTHOR]