On the validity of the Hagen and Beverloo formulas for grains discharge through thin sidewalls of bins

In this work we show through experiments, by using cohesionless granular materials, that a simple formula proposed to estimate the granular outflow from orifices in thick sidewalls is also valid for thin sidewalls. The use of such a formula entails the approximate validity of the classical Hagen and Beverloo formulas for granular samples composed of small and large grains, respectively. Also, an estimation of the involved error when the wall thickness is left aside also is given.