How to Maintain a Cutthroat Flume
For proper flow measurement, a Cutthroat Flume installation must be periodically inspected.
This inspection should include the channel in which the flume is installed, the flow entering / exiting the flume, and the flume itself.
Channel inspection
The upstream channel banks should be clear of vegetation or debris that could affect the flow profile entering the flume (upstream) or restrict flow out of the flume (downstream).
Inspect the upstream channel to make sure that flow is not bypassing the flume.
Inspect the downstream channel to make sure that scouring is not occurring.
Any hydraulic jump should be at least 30 times the maximum head (Hmax) upstream of the flume.
Flow inspection
Flow entering the flume should be tranquil and well distributed.
Turbulence, poor velocity profile, or surging should not be present.
The Froude (Fr) number should, ideally, be 0.5.
As the Froude number increases so does surface turbulence.
Flumes accelerate sub-critical flow (Fr < 1) to a supercritical state (Fr 1>).
Flumes experiencing flows greater than unit (Fr = 1) will not accurately measure flow.
Flume Direction
For first time inspections, make sure the flume is installed facing the right way.
The section with the shorter contraction must be upstream / the loner contraction section downstream.
Flume InspectioN
For first time inspects, make sure the flume is installed facing the right way.
The section with the shorter contraction must be upstream / the loner contraction section downstream.
Flumes must be level from front-to-back and from side-to-side.
Earthen installations are particularly susceptible to settling due to wet / dry and freeze / thaw cycles.
Flow surfaces are to be kept clean of surface buildup or algal growth. Scrubbing or a mild detergent can be used.
GALVANIZED SPECIFIC MAINTENANCE
Check for corrosion.
Any corrosion should be removed, the area dried, and then cold galvanization applied.
