Generalized Rectangular Weir Equations

Abstract

Most of the existing weir formulas lose their significance as the ratios of head to height or head to width become large. A full range equation valid for all values of head-to-height ratio has been developed for a sharp crested weir. Also for finite crested weirs a full range equation valid for all values to head-to-width ratio has been presented. This equation covers narrow crested, broad crested and long crested weirs. Providing a smooth transition between sharp crested and finite crested weir equations, a generalized rectangular weir equation has been evolved. This equation is applicable to all head-to-height ratios and all head-to-width ratios or sharp crested and finite crested weirs. This equation is applicable to all types of rectangular weirs-sharp crested or broad crested, and sills. It is hoped that the equation will be useful for analysis and design purposes.