Stilling
basins with dentiated or continuous sills are frequently
used as energy dissipaters downstream of hydraulic
structures. In this study, experiments are conducted to
evaluate effects of a single vertical continuous sill and
its position on control of depth and length of a forced jump
in stilling basin without considering tailwater depth which
is variable and totally controlled by downstream river
conditions. A sill with five different heights was placed at
three different longitudinal distances along a scaled model
of a stilling basin. The hydraulic characteristics of the
jump were measured and compared with the classical hydraulic
jump under variable discharges. Results of experiments
confirmed significant effect of the sill on dissipation of
energy. A new relationship was developed between sill height
and position, sequent depth ratio, and length of stilling
basin. The advantage of the proposed relationship in
practice is its capability to design stilling basin where
tailwater depth is unpredictable
