B-Jump in abruptly expanding channel

Motoyasu Ishikawa, Masayuki Takahashi, Youichi Yasuda, Iwao Ohtsu

Friday 3 july 2015

9:15 - 9:30h at Amazon (level 1)

Themes: (T) Water engineering, (ST) River and coastal engineering

Parallel session: 14E. Engineering - River

For a B-jump in abruptly expanding channels, both symmetric and asymmetric flows are observed. The hydraulic condition required to form a symmetric flow is necessary for design purposes. In this study, the flow conditions of the B-jump are classified into symmetric flow, periodically deflected flow, and asymmetric flow, according to the change of the tailwater level. An expression is presented for the formation of each flow condition, determining the hydraulic condition for the formation of symmetric flow. The relation of the sequent depths of the jump is derived from the momentum equation. Additionally, the expression for the length of the jump is determined by considering the physical meaning of the jump length.