Control of Transient Free - Surface Flow

A theory is presented to define methods of optimum gate operation for altering flow conditions in an open channel. The analytical procedure prescribes the motion of the control devices in the channel so the transient conditions are known and controlled during the period when the flow is being changed from one given situation to another desired flow condition. The method is applicable to cases of initiating flow, increasing flow, decreasing flow, or stopping flow in irrigation channels, power channels, forebay channels to pumping stations, etc. The theory is developed from the basic differential equations for unsteady flow in a prismatic channel, including frictional losses. Two examples are detailed in this study.