Alternative Linear Weir Design

Abstract

Weirs are devices installed in channels by means of which flow may be measured within a given degree of accuracy. Linear weir flow‐measuring devices introduce less relative error in discharge measurement. The design of a linear weir is such that the base approaches infinity; this makes its theoretical design physically unrealizable. Various attempts have been made to achieve a practical weir profile by cutting off the infinite bottom wings and providing base weirs of different shapes. Furthermore, all these designs use a constant discharge coefficient, whereas there is a considerable variation in the discharge coefficient with the head/weir‐height ratio. A linear weir profile that includes the variation of discharge coefficient and does not require base and datum corrections is presented herein. A design example has also been included.