A Crump weir is a standard design weir for moderate flow rates.
Note: When the downstream level of water in the river should be taken into account for backwater correction, use the crumpWeirBackwater transformation instead of the crumpWeir transformation.
Furthermore, one to three crests can be defined. The first crest is mandatory and only contains the relativeLevel attribute. The relativeLevels are the required head level adjustments for each crest of the weir. Each relativeLevel is subtracted from the headLevel to give a true indication of what the actual head level is over each crest. This is required as each crest at a particular weir may have different heights.
The second and third crests also must contain the width attribute. User has the choice between entering one of the following:
Calculates discharge of a triangular profile or Crump weir. The flow calculations are done using measurements taken at the weir.
The following formula is used:
Parameters:
Q = Cg . Cd . b . H1^(3/2)
Cg = sqrt(g)
Cd = 0.633
The modular limit h2/h1 = 0.75.
If this value is exceeded a missing value will be entered for the discharge. Further limiting conditions are:
P >= 0.06 m
b >= 0.30 m
h1/P <= 3
b/h1 >= 2