Pakistan Research Repository

HYDRAULIC JUMP CONTROL AND ENERGY DISSIPATION

Bhutto, Hussain Bakhsh G. (1987) HYDRAULIC JUMP CONTROL AND ENERGY DISSIPATION. PhD thesis, Mehran University of Engineering & Technology, Jamshoro.

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Abstract

In many types of hydraulics structures a considerable portion of the kinetic energy in supercritical flow must be dissipated to prevent scour of the mobile boundary channel downstream from the structure. Various methods of energy dissipation have been used to achieve tranquil flow conditions as the flow enters the downstream channel. The primary purpose of all such methods is to convert as much as possible the kinetic energy of flow into turbulent energy and ultimately into heat energy. This objective is most effectively accomplished by means of a local phenomenon known as a hydraulic jump which may assume several distinct forms depending on the geometry of channel and tailwater conditions. Thus hydraulic jump is a phenomenon well known to hydraulic engineers as a useful means of dissipating excess energy and thereby prevent scour below overflow spillways, chutes and sluices. The value of relevant hydraulic data in the design of such process has initiated many experimental investigations, so that the dimensions and characteristics of a hydraulic jump in a rectangular channel may be predicted within practical limits. To fill the needs for upto-date hydraulic design of stilling basins involving formation of hydraulic jump, a research program on this subject is undertaken with a study of the hydraulic jump, observing all phases as it occurs in open channel flow. With a broader understanding of this phenomenon it is then possible to proceed to the more practical aspects of stilling basin design. The work reported in this thesis is an attempt to investigate theoretically and experimentally the characteristics of hydraulic jump under different situations, and to bridge the gaps existing in the research work already done in this regard. The text comprises of seven Chapters, viz. Introduction, Free Hydraulic Jump on Horizonta1 Bed, Submerged Hydraulic Jump on Horizonta1 Bed, Free Hydraulic Jump on Sloping Bed, Submerged Hydraulic Jump on Sloping Bed, Jump Control and Conclusions and Suggestions. Chapter-I deals with the fundamental aspects and basic equations governing the characteristics of hydraulic jump. Chapter-II deals with the important dimensions of free hydraulic jump in a rectangular horizontal channel. Experimental data have been collected and some analytical and empirical equations have been developed and verified. In Chapter-III qualitative and quantitative aspects of sub-merged hydraulic jump forming on horizontal bed has been investigated. Relatively simple and elaborated empirical equations for important parameters have been developed. Chapter-IV deals with experimental evaluation of some vital factors, viz. Jump factor and shape factor for free, hydraulic jump on sloping bed. Besides this important characteristics of free hydraulic jump forming on sloping bed have been quantified analytically and empirically. Chapter-V dealing with entirely a new topic which is also the core of this research work is the submerged hydraulic jump on sloping bed. In this chapter the phenomenon has been studied theoretically and experimentally and some useful analytical and empirical equations pertaining to dimensions of the jump are derived. Chapter-VI deals with the study for ensuring the formation of the hydraulic jump and to control its position. Sills of different designs and an abrupt drop in channel, bed have been used to ensure jump formation and control its position under all the operating conditions. Some necessary modifications in analytical treatment have been made to investigate the performance of control structures. Chapter-VII deals with conclusions and Suggestions of the research work explained in the fore going chapters.

Item Type:Thesis (PhD)
Uncontrolled Keywords:Energy Equation, Momentum Equation, Hydraulic Jump, Jump Efficiency, Kinetic Energy, Supercritical Flow,
Subjects:Engineering & Technology (e) > Engineering(e1)
ID Code:180
Deposited By:Mr Ghulam Murtaza
Deposited On:28 Sep 2006
Last Modified:04 Oct 2007 21:00

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