Basic Hydraulic Concepts

Abstract

The design of a hydraulic structure requires prediction of the relationship between flow characteristics, especially discharge and local flow depths, and the geometry of the structure. A classification of associated flow types is presented, followed by application of the laws of conservation of mass, energy and momentum for describing steady uniform and nonuniform flow conditions. Steady uniform flow is used as an instance to develop the commonly-used resistance relationships (Darcy-Weisbach, Chézy and Manning). Steady rapidly varied flow is described through applications of specific energy and the momentum function, leading to exposition of the key concept of controls. The classification of steady gradually varied water surface profiles is presented, followed by computational methods for their quantitative description.