NO. 47 - July 1954 



I-A "Stability of Oscillatory Laminar Flow Along a Wall" by 

 F Huon Li 



Results are reported for a laboratory study of the 

 transition from laminar to turbulent flow in an 

 oscillatory boundary layer near the solid bottom 

 caused by a surface wave. For experimental convenience 

 observations were made at a plate oscillating in still 

 water. The relationships between the two flow condi- 

 tions are discussed, and experimental results including 

 observations for both smooth and rough surfaces are 

 given. 



NO. 48 - August 1954 



I-A "Sand Movement by Waves" by Theodore Scott 

 C 



A series of two-dimensional experiments were carried 

 out in a laboratory wave flume using waves of both 

 high and low steepness ratios to investigate the move- 

 ment of sand along the bottom. Results presented are 

 primarily on the effect of long and short period waves 

 on beach and bar formation and onshore-offshore trans- 

 port of material. Importance of relative amplitudes 

 of vertical and horizontal components of orbital wave 

 motion on sand movement and bottom ripple formation 

 is discussed. Information is also presented on the 

 mechanics of ripple formation and their relation to 

 onshore-offshore movement. 



NO. 49 - August 1954 



II-B "Bore Hole Studies of the Naturally Impounded Fill at Santa 

 C Barbara, California" by Parker D. Trask and Theodore Scott 



A series of 7 bore-holes were drilled in the accumulated 

 fill area west of the breakwater and the cores analyzed. 

 The fill area overlays areas formerly covered by sea 

 water and thus information was obtained as to how sand 

 accumulates both offshore and on the beach. Analysis 

 and results of the study are presented. 



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