Prof. Dr. Aminuddin Ab Ghani

Specific Energy &

Hydraulic Jump

Reference

Chapter 13OPEN-CHANNEL FLOW

Lecture slides byMehmet Kanoglu

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fluid Mechanics: Fundamentals and Applications2nd EDITION IN SI UNITS

Yunus A. Cengel, John M. CimbalaMcGraw-Hill, 2010

SPECIFIC ENERGY

The specific energy Es of a liquid in an open channel is the total mechanical energy (expressed as a head) relative to the bottom of the channel.

SPECIFIC ENERGY

The specific energy reaches a minimum value Es, min at someintermediate point, called the critical point, characterized by the criticaldepth yc and critical velocity Vc. The minimum specific energy is also called the critical energy.

Hydraulic jump

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Schematic and flow depth-specific energy diagram for a hydraulic jump (specific energy decreases).

The energy dissipation ratio represents the fraction of mechanical energy dissipated during a hydraulic jump.

The fraction of energy dissipation ranges from just a few percent for weakhydraulic jumps (Fr1 < 2) to 85 percent for strong jumps (Fr1 > 9).

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