Exit Loss Equation

The exit loss, h
o
, is a function of the change in velocity at the outlet of the pipe as shown in Equation 10-37.
EquationObject314376
Equation 10-37.
where:
  • v = average outlet velocity (fps or m/s)
  • v
    d
    = channel velocity downstream of the outlet (fps or m/s)
  • C
    o
    = exit loss coefficient (0.5 typical).
The above assumes that the channel velocity is lower than the outlet velocity. Note that, for partial flow, where the pipe outfalls into a channel with water moving in the same direction, the exit loss may be reduced to virtually zero.