Energy dissipation in a launch channel focused on increasing the dissipation of
initial water flow energy to protect against hydraulic structure failure. This was
achieved by using rectangular baffle blocks placed within the launch channel,
varying in angles and flow rates. The aim of this study was to determine the
impact of different angles of the rectangular baffle blocks on flow energy
dissipation downstream of a spillway structure. A two-dimensional experimental
research method was employed to assess the water energy dissipation by varying
the angles of the baffle blocks in the launch channel. The results of this study
indicated that in the rectangular baffle block type with an angle variation of 300,
the relative energy dissipation was directly proportional to the upstream and
sequential Froude numbers. In contrast, for the baffle blocks with an 1800 angle
variation, the relative total energy dissipation decreased as the upstream and
sequential Froude numbers increased. The maximum value of the relative total
energy dissipation occurred when the water level above the crest was high, but
the minimum value happened when the water level above the crest was low. One
key finding of this study was that the rectangular baffle blocks with a 300-angle
variation and a relative water surface height of 2.5 cm above the crest provided a
maximum total relative energy dissipation of 53.66%. The advantage of using
rectangular baffle blocks was in their ability to gradually slow down the flow
velocity through the gaps between the angled blocks, preventing the formation of
back momentum in the flow.
Keywords: Launch Channel, Spillway, Baffle Block, Flow Energy