AFT Application Topics
Weirs are often used to measure flow rates in low head, high flow situations, often on rivers and other open-channel flow applications. In addition to allowing a relatively easy, accurate, and inexpensive means to measure flow rates, they can alter the steady-state and transient characteristics of the entire flow path.
While AFT products are primarily intended to be used in closed and liquid full systems, there are some instances where the inclusion of a Weir in an AFT Fathom or AFT Impulse model is desirable. It is therefore possible to hydraulically model Weirs, accounting for the effects they create in a piping system.
Weirs can have a dampening effect on changing flow parameters, which can be observed in the AFT Impulse or AFT Fathom XTS add-on module, depending on whether the changes are sudden transients or slow system changes.
The software allows flexibility in defining a rectangular, v-notch or Cipolletti Weir, allowing the user to fully specify the size of the notch, upstream basin, and downstream basin.