RBC Flume Design

Two design goals determined the shape of the RBC Flume:  ease of manufacture and conformance to the typical shape of irrigation ditches and furrows.

As a result, the RBC Flume has a flat, constant trapezoidal cross-section and a flat-sided ramp rising up in the throat.  

The trapezoidal cross-section makes the RBC Flume easier to adapt to existing channels (unlike the Parshall).  The shape eliminates the need to either set the flume above the channel floor or modify the downstream channel.

RBC Flume Dimensions

RBC Flumes are scale models of each other, with the base width the determining factor for all other dimensions.  

Note that the dimensional tolerances of the throat are critical as a difference of 1% error in throat cross-section will cause an error in the discharge measured of 1%  

The dimensions for the RBC Flume can be found in:

• Clemmens, A., Bos, M., and Replogle, J., Portable RBC Flumes for Furrows and Earthen Channels, Transactions of the ASAE, Vol. 27, No. 4, July/August 1984 

Throat length and ramp length have more margin for dimensional tolerance, but the intersection between the flume floor / ramp / throat must be distinct.

RBC FLUME MASTER DIMENSIONS