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Open channel hydraulics for engineers. Chapter 3 hydraulics jump

In this chapter, the specific-energy concept is introduced and, then, the momentum principle is applied to open-channel flows. The hydraulic jump and its types are defined and classified. This chapter introduces how to determine the direct and submerged hydraulics jump; their characteristics are presented | OPEN CHANNEL HYDRAULICS FOR ENGINEERS ----------------------------------------------------------------------------------------------------------------------------------- Chapter HYDRAULIC JUMP _ 3.1. Introduction 3.2. Specific energy 3.3. Depth of hydraulic jump 3.4. Types of hydraulic jump 3.5. Hydraulic jump formulas in terms of Froude-number 3.6. Submerged hydraulic jump _ Summary In this chapter, the specific-energy concept is introduced and, then, the momentum principle is applied to open-channel flows. The hydraulic jump and its types are defined and classified. This chapter introduces how to determine the direct and submerged hydraulics jump; their characteristics are presented. Key words Momentum; hydraulic jump; specific energy; critical; Froude-number; direct and submerged jump _ 3.1. INTRODUCTION The most common application of the momentum equation in open-channel flow deals with the analysis of the hydraulic jump. The rise in water level, which occurs during the transformation of the unstable “rapid” or supercritical flow to the stable “tranquil” or subcritical flow, is called hydraulic jump, manifesting itself as a standing wave. At the place, where the hydraulic jump occurs, a lot of energy of the flowing liquid is dissipated (mainly into heat energy). This hydraulic jump is said to be a dissipator of the surplus energy of the water. Beyond the hydraulic jump, the water flows with a greater depth, and therefore with a less velocity. The hydraulic jump has many practical and useful applications. Among them are the following: Reduction of the energy and velocity downstream of a dam or chute in order to minimize and control erosion of the channel bed. Raising of the downstream water level in irrigation channels. Acting as a mixing .