Nonlinear PLS Method for Side Weir Flows

Side weirs are flow-regulating devices commonly encountered in hydraulic engineering. In the past, the discharge coefficient for flow past a side weir was investigated experimentally by many researchers. In this study, a modified discharge coefficient Cd for side weirs in rectangular channels and circular channels is defined. The multivariable nonlinear partial least square (PLS) method is used to determine the empirical equations relating Cd with the dimensionless weir parameters F1 , S∕ Y1 , and L∕D . Compared to the previous studies, the procedures to calculate the discharge of the side weirs is simplified. The discharge predicted using the empirical equations based on the nonlinear PLS method is in good agreement with the measured discharge. The nonlinear PLS method can also be applied to many other hydraulic flow configurations characterized by a large number of variables.