Higher order critical flow condition in curved streamline flow

A new extended Bernoulli energy equation, which is valid for moderately curved channel flows, is presented. From this generalized energy equation, a higher order critical flow condition valid for curved streamline flow was developed. As a practical application, the flow over a circular-crested weir was studied. The proposed new critical flow theory improves the results of a previous lower order theory up to a dimensionless specific energy of 2, thus obtaining accurate results in situations in which the velocity is non-uniform, the pressure non-hydrostatic, and the conventional critical flow theory not valid.