This feature lets you select the design of a Reg-U-Flo ® Vortex
Valve as manufactured by Hydro International. See
www.hydrointernational.biz for details and the locations of
licensees and distributors throughout the world.
There are four types of device as illustrated below, known by the
four letter codes ‘CH’, ‘CX’, ‘SH’ and ‘SXH’
These devices are designed to operate
in two modes depending on the driving head. Initially, with low heads
the device acts in a similar fashion to an orifice, but as the head
increases, the swirl at the entrance creates a vortex that restricts
the outflow. The result is that the stage discharge curve is S-shaped
and exhibits two turning values. A typical stage-discharge curve is
The discharge at the lower turning
point is called the Flush Discharge. The reduction of discharge
between the two turning points is called the ‘kick-back’. In general,
the outlet control should be designed to operate within the stable
region between the two head values shown in the plot.
In operation with a typical inflow
hydrograph the operating point will migrate upwards through the three
portions of the S-curve as the inflow increases This is illustrated
Tutorial lesson 25 which describes the response of a simple
detention pond to three inflow hydrographs of different peak flow
MIDUSS comes with a wide
variety of pre-defined valves and curve files however it is likely you
will need a customized valve and curve to make your detention pond
MIDUSS includes a tool
named Make Vortex File which helps you create a file that describes
the stage-discharge curve of any of the four types of vortex valves.
This file is then used within the detention pond design as a special
form of outflow control.
Below are example screen
shots of the file being generated.
The Initial ‘Make Vortex File’
Data values computed after defining Qflush