Caltech Library System

About | Browse | Search | Caltech Student Instructions

Type of Document	Dissertation
Author	Kennedy, John Fisher
URN	etd-06222006-153051
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-06222006-153051
Title	Stationary waves and antidunes in alluvial channels
Degree	PhD
Option	Civil Engineering
Advisory Committee	Advisor Name Title Norman H. Brooks Committee Chair Vito A. Vanoni Committee Member
Keywords	none
Date of Defense	1960-01-01
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A theoretical and laboratory investigation was made of antidunes and associated stationary waves. The objectives were to determine the factors involved in the formation of antidunes, the characteristics of the stationary waves, and the effects of antidunes and waves on the friction factor and sediment transport capacity of streams. In the potential flow solution for flow over a wavy bed it was hypothesized that the flow shapes the erodible sand bed by scour and deposition to conform to a streamline of the flow configuration for which the energy is a minimum. Under this hypothesis, flow over antidunes is the same as the segment of flow above an intermediate streamline of the fluid motion associated with stationary gravity waves (waves with celerity equal and opposite to the flow velocity) in a fluid of infinite depth. For a velocity V the wave length, [lambda] is given by [lambda] and waves break when their height reaches 0.142[lambda]. Laboratory and field data for two-dimensional antidunes confirmed these relations. Forty-three experimental runs in laboratory flumes were made for different depths and velocities and bed sands of two different sizes (0.55 mm and 0.23 mm). No general criterion for the formation of antidunes or the occurrence of breaking waves could be formulated because of inadequate knowledge of the complex sediment transport phenomenon. Qualitatively, it was found that for a given sand, the critical Froude number for the occurrence of breaking waves decreased as the depth was increased. Over a certain range of depth and velocity it was found that the flow formed waves and antidunes or was uniform depending on whether or not the flow was disturbed to form an initial wave. Waves that did not break had no measurable effect on the transport capacity or friction factor, but breaking waves increased both of these quantities.
Files	Filename       Size       Approximate Download Time (Hours:Minutes:Seconds)     28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access    Kennedy_jf_1960.pdf 12.33 Mb 00:57:04 00:29:21 00:25:41 00:12:50 00:01:05