Flat V weirs are used to calculate the flow of a river or stream. Predominantly, Flat V weirs are used where the flow rates are low and river sections quite narrow.
Input
- headLevel: is the upstream level of water in the river measured from the top of the crest at the bottom of the V.
- tailLevel: is the downstream level of water in the river measured from the top of the crest at the bottom of the V and can be positive or negative.
- type: type can be 'simple' or 'crest_tapping'. With 'crest_tapping' the pressure tapping measurements are taken and used for the flow calculation.
Coefficient set
- pUpValue: is the distance in metres from the bottom of the river to the top of the crest.
- width: is the width of the weir crest in metres. Note that there can only be one crest at a Flat V weir.
- cSlope: is the slope of the "V" at the crest. The slope is the ratio of the horizontal distance over the vertical distance one metre (1m) expressed as a number.
- sSlope: is the side slope of the weir. Most Flat V weirs don't have side slope. The slope is the ratio of the horizontal distance over the vertical distance one metre (1m) expressed as a number. There are two different calculation methods for Flat V weirs that are identified by either having the s-slope equal to 9999, or an actual value.
The figure below shows the relation between the input timeseries and coefficients, with an example for the cSlope value in case the slope of the weir is 15 degrees. Notice that headLevel and tailLevel are relative to the crestlevel (the point of the V).
Output
- discharge: discharge of the weir.
Description
Calculates discharge of a flat v weir with backwater correction. The flow calculations are done using measurements taken at the weir.
