Question

Derive the formula for discharge for a sharp crested rectangular weir

Answer 1

Sharp-crested rectangular weirs are commonly used as discharge measuring facilities in open channels and laboratories. Weir plate height and width are two key elements in shaping the head-discharge relationship. The experiments demonstrate that for a certain range of discharge over the weir, height of the plate is no longer affecting the discharge. Average velocity over the weir plotted against the weir head has a unique behavior. This behavior can be used in such a way that can define a weir velocity to estimate the discharge rather than using the discharge coefficient. Hence a more accurate outcome and a more compact and short form of expressions are expected to be obtained. The present study focuses on the experimental investigation of various possible formulations of the weir velocity for available weir heights and widths