GC: n

CT: There are many types of open channel flow measuring devices available. Of these, flow measuring flumes are one of the most commonly used.
How a Flume Operates
Flumes are specially shaped, fixed hydraulic structures that under free-flow condtions force flow to accelerate in such a way that the flow may be characterized by a know relationship between the liquid level (head) at a single specified location and the flow rate. Acceleration is provided by converging the sidewalls, raising the bottom, or a combination of both.
Sections of a Flume
A flume normally consists of a three sections: a converging section, a throat section, and a diverging section. Examples of this configuration include: Parshall, Trapezoidal, Cutthroat, and RBC flumes – although technically the Cutthroat flume omits the throat section as it has no length in that style of flume.
Styles that omit the discharge section include: Palmer-Bowlus, HS / H / HL and Montana flumes.

S: OPENCHANNEL – http://www.openchannelflow.com/products/flumes (last access: 31 December 2012)

N: 1. late 12c., “stream,” from Old French flum “running water, stream, river; dysentery,” from Latin flumen “flood, stream, running water,” from fluere “to flow” (see fluent). In U.S., used especially of artificial streams channeled for some industrial purpose.
2. Man-made channel with clearly specified shape and dimensions which may be used for the measurement of discharge.
3. An artificial channel, with clearly specified shape and dimensions, which may be used for measurement of flow. (Definition standardized by ISO.)
4. flume: term standardized by ISO.
5. Advantages Over Weirs: Flume head loss is less than about one-fourth of that needed to operate a sharp-crested weir having the same control width. Another advantage compared to most standard weirs is that for a properly designed and installed flume, the velocity of approach is a part of the calibration equations. Unauthorized altering of the dimensions of constructed flumes to obtain an unfair share of water is difficult and, therefore, not likely. Unlike weirs, most flume styles allow for the ready passage of sedimentation and floating debris – reducing the time and effort associated with maintaing a flume.

S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=flume&searchmode=none (last access: 31 December 2014). 2. GDT (last access: 31 December 2014). 3 & 4. TERMIUM PLUS (last access: 31 December 2014). 5. http://www.openchannelflow.com/products/flumes (last access: 31 December 2014).

SYN: 1. measuring flume. 2. control flume, rating flume.

S: 1. TERMIUM PLUS (last access: 31 December 2014); GDT (last access: 31 December 2014). 2. TERMUM PLUS (last access: 31 December 2014).

CR: weir