Hydraulic Design of Flume Aqueducts

An aqueduct is a canal conveyance structure utilized to cross a river when the bed level of the canal is clearly above the river high flood level. One such aqueduct structure is a reinforced concrete rectangular flume having a width usually less than that of the canal for economic reasons. The ratio of the width of the flume to that of the canal is termed flume ratio. At present, the only criterion for choosing the flume ratio is that the Froude number of flow in the flume should not exceed a specified value in the subcritical range. Using the specific energy diagram, three approaches are described for hydraulic design of the flume. Equations are presented for prediction of flow conditions in the flume, bed elevation of the flume and head loss due to the structure. The three approaches have been compared for their use in actual practice.