Long-throated flumes and broad-crested weirs

Abstract

Vital for water management are structures that can measure the flow in a wide variety of channels. Chapter 1 introduces the long-throated flume and the broad-crested weir; it explains why this family of structures can meet the boundary conditions and hydraulic demands of most measuring sites.Chapter 2 records the history of these structures. It describes how the hydraulic theory of flumes and weirs, and their design, developed separately. The chapter concludes by reporting recent attempts to develop a generally valid theory for any long-throated flume or broad-crested weir in any channel. The remainder of the thesis explains the steps taken to develop a procedure that yields the hydraulic dimensions and rating table of the appropriate weir or flume. The major steps cover the hydraulic theory of flow through control sections of different shapes and dimensions, the theory and procedure of estimating the head loss required for modular flow, the boundary conditions of the channel, and the demands placed on the structure regarding the range and accuracy of its flow measurements