Viscosity and Surface Tension Effects on Weir Flow

Abstract

Weirs have been in use for a number of decades for the measurement of discharge in channels. The existing discharge relations for weirs predict the discharge reasonably well at high heads; however, the accuracy of these relations is questionable at low heads. This is mainly due to the fact that the effects of viscosity and surface tension of the liquid are important at low heads and these have not been properly considered in deriving the discharge relations.