Contraction and expansion losses are typically small compared to friction losses but become more significant around culvert and bridge openings. Channel Studio evaluates these losses using the following equation:
Where:
hce = The energy loss from expansion or contraction
C = The contraction or expansion coefficient (See Project Settings for default values)
This method assumes that a contraction is occurring whenever the velocity head downstream is greater than the velocity head upstream. Likewise, when the velocity head upstream is greater than the velocity head downstream, it is assumed that a flow expansion is taking place.
