Transitional Expanding Hydraulic Jump

Abstract

This note presents the general features of velocity and variation in length scales of the transition expanding jump, free jump, and wall jet in the rectangular horizontal open channel. The experiments were performed for a range of Froude numbers from 2 to 6 and at an abrupt expansion ratio of 2. The results indicate that the postdepth y2 required to form an expanding jump is distinctly smaller than that for the corresponding classical jumps. The expanding jump length was 1.25 times the corresponding free jump length. The velocity profiles for the transition jumps were similar to those for the wall jet. For the transitional expanding jumps, the boundary layer thickness δ , normalized by the supercritical flow depth y1 , grows more rapidly relative to the free jumps. The normalized boundary layer thickness δ in terms of the length scale of b equal to the flow depth y , where the velocity u is equal to half of the maximum velocity um , against the longitudinal direction x normalized by y1 , which was stabili...