NO. 115 - June 1959 



" Suspended Sediment Sampling in Laboratory Wave Action " 

 by J. C. Fairchild 



Data and some analysis on the quantity of sediment placed 

 in suspension by wave action are presented. The data 

 were obtained in laboratory wave tanks and concern the 

 collection and analysis of wave-induced suspended sediment 

 using waves of both small scale (2 to 6-inch heights) and 

 relatively large scale (2 to 6-foot heights). Quantita- 

 tive analysis relates principally to the effect of water 

 temperature on concentration and size characteristics of 

 suspended material. However, considerable discussion is 

 devoted to procedures and techniques for sampling sus- 

 pended material and the physical procedures governing 

 its behavior. 



NO. 116 - July 1959 



"On the Theory of the Highest Waves " by J. E. Chappelear 



As suggested by Michell, properties of the highest periodic 

 gravity waves which can exist in steady two-dimensional 

 flow, neglecting viscosity, are calculated. The "highest 

 wave" is defined as one satisfying the criterion of Stokes 

 that the particle velocity at the wave crest be equal to 

 the wave velocity. The theory is valid for all values of 

 the parameter d/T 2 greater than 0.2 ft/sec 2 . The highest 

 wave in deep water, whose properties were first calculated 

 by Michell and by Havelock, is obtained as a special case. 



NO. 117 - August 1959 



" The Damping of Oscillatory Waves by Laminar Boundary Layers " 

 by P. S. Eagle son 



Results of an analytical and experimental investigation 

 of the shearing stresses exerted on a smooth bottom by 

 passage of oscillatory water waves are presented. Force 

 measurements including time-history of instantaneous force 

 during passage of waves and simultaneous measurements of 

 instantaneous wave characteristics were made and corrected 

 for pressure and inertia forces to obtain net tangential 

 forces. Average resistance and damping coefficients 

 were derived in terms of wave properties. Analysis of 

 experimental results using these coefficients consistently 

 showed experimental bottom shearing stresses greatly ex- 

 ceeded those predicted by theory. The boundary layer was 

 than assumed to be disrupted each half circle due to flow 



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