Flow structure, air entrainment and turbulence characteristics in a classical hydraulic jump, a review.

In the last two decades, the hydraulic jump has been extensively studied. In this article, attempt is made to have a comprehensive look at different characteristics of this complicated phenomenon. The aim of the present work is classification, comparison, and analysis of many research works on hydraulic jumps during the past years. It was found that there was no significant difference between jump characteristics such as the sequent depth and surface profile with developed or undeveloped approach flow, but air–water characteristics such as void fraction and bubble count rate are significantly affected. The present study also discusses the research results on pressure fluctuations, velocity field, turbulence characteristics, and air–water properties in a hydraulic jump. Investigating previous studies shows that most of the relationships presented for different characteristics of the hydraulic jump such as velocity or air concentration are dependent on other variables which are not available without measurements. The length of the stilling basin is considered equal to the length of the jump. Various definitions are given for the jump length. The results show that using the decay rate of pressure fluctuation, the stilling basin length could be calculated by less than 5% difference compared to the defined USBR I standard stilling basin length. [ABSTRACT FROM AUTHOR]