Hydraulic jumps on adverse slopes

Abstract

The adverse hydraulic jump has been investigated and analyzed in order to derive the limiting design parameters for this type of jump. The limiting design condition refers to the adverse jump when it occurs entirely on the adverse slope; as such, this jump was difficult to establish at Froude numbers less than 9 and required continuous tailwater adjustment to maintain a stationary position for Froude numbers less than about 4. It was found that the sequent depth as well as the roller length for the adverse hydraulic jump is less than that for a horizontal jump with the same approach conditions. The results for the limiting adverse jump are compared with published results on a stabilized jump that starts on a positive slope and ends on an adverse slope. A momentum based theory is presented to determine the sequent depth ratio. An empirical equation is presented for the roller length.