Parallel vs. perpendicular area orifice orientation in composite outlet structures


  Applies To     
  Product(s):
SewerGEMS, CivilStorm, PondPack
 
  Version(s): All  

Problem

When choosing 'Area Orifice', what is the difference between a parallel and perpendicular orifice orientation in the composite outlet structure?

Solution

The orientation of the orifice is with respect to the water surface. A parallel orifice therefore means that the orifice is on the bottom of the pond, like a drain in a tub.

A perpendicular orifice means that the location is on the side of the pond (or riser). The shape of the orifice is unimportant since it is using the orifice equation to find the flow. The perpendicular orifice is unique in that the flow may vary depending on the elevation of pond. The program first finds the flow at the top of the orifice (meaning that it is fully submerged). It assumes the flow at the bottom is zero and uses linear interpolation for points in between.

 

Parallel Orientation

Perpendicular Orientation