Volume 34 • Number 3 • 2011   • Free-Surface Flow Under a Sluice Gate from Deep Water L. H. Wiryanto, J. Widjaja and H. B. Supriyanto Abstract. Fully nonlinear solutions of free surface flow under a sluice gate are presented in this paper. The fluid upstream is assumed to be infinite in depth, and it flows under the gate forming a uniform stream far downstream. The problem is solved numerically by a boundary element method derived from the integral equation along the free surface. The numerical procedure is able to obtain solutions for upstream Froude number $F\geq 0.192$. A free surface with back flow near the edge of the gate is indicated for $F\leq 0.317$. As the limiting case, free surface flow with a stagnation point at the edge of the gate can be computed for $F=0.192$. 2010 Mathematics Subject Classification: 76B07, 76M15. Full text: PDF