The annular flume was designed for use in sediment transport experiments. The flume consists of two primary parts, an annular U-shaped bottom channel with a mean diameter of 130-cm, a width of 20-cm and a depth of 45-cm, and a plexiglass lid that recesses inside of the annular bottom channel. The lid can be raised or lowered on this shaft allowing flow depths between 20- and 40-cm. Three holes on the lid allow the insertion measuring devices into the flow. A wooden shelf is mounted on the lid support arms to hold the data logger of the measuring devices and other equipments.
The bottom channel and lid rotate independently and in opposite directions in order to minimize the effects of secondary re-circulatory currents on the flow. A control system composed by two magnetic sensors, two motor controllers and control software implemented in Labview can be used to set the direction and the speed of rotation of the lid and channel The maximum turning speeds are +/-16 RPM and +/-10 RPM for the lid and channel respectively.
Previously, the annular flume has been used to examine the settling and sediment oxygen demand of combined sewer overflow sediments1 and the erosional characteristics of mine tailing deposits.
1 Briskin, Brigid and Marcelo H. García. 2002 August. “Investigation of Settling and Oxygen Demand of Resuspended Combined Sewer Overflow Sediments Using an Annular Flume – McCook Reservoir Studies.” University of Illinois at Urbana-Champaign. Civil Engineering Studies, Hydraulic Engineering Series No. 72.