Profile: OPENCHANNELFLOW mainly focuses on measurement, conditioning, and control of flow of water. There are many types of open channel flow measuring devices available. Of these, flow measuring flumes are one of the most commonly used. Flumes are specially shaped, fixed hydraulic structures, that under free-flow conditions force flow to accelerate in such a way that the flow may be characterized by a known relationship between the liquid level (head) at a single specified location & the flow rate. Acceleration is provided by converging the sidewalls, raising the bottom, or a combination of both. Flumes range in size from very small to very large, with throat widths ranging from 1 inch [2.54 cm] to 50 feet [1,524 cm]. Measurable flows can range from 0.03 to 3,000 cubic feet per second (ft3/s) [0.849 to 84,960 l/s]. Some flumes have calibrations available for submerged conditions where the critical depth has been nearly drowned by downstream backwater either purposely or by later increase of downstream flow resistance.