PREFACE 



This Symposium is the sixth in a series each of which has been concerned 

 with various aspects of Naval Hydrodynamics . The first (held in September 

 1956) presented critical surveys of Hydrodynamics that are of significance in 

 naval science. Subsequent meetings were to be devoted to one or more topics 

 selected on the basis of importance and need for research stimulation, or of 

 particular current interest. 



In keeping with this objective, the second symposium (August 1958) had 

 for its subject the areas of hydrodynamic noise and cavity flow, the third 

 (September 1960) was concerned with the area of high performance ships, the 

 foxirth (August 1962) emphasized the topics of propulsion and hydroelasticity, 

 and the fifth (September 1964) addressed itself to coverage of the areas of 

 ship motions and drag reduction. 



Still continuing with the original plan, a threefold theme was selected for 

 the present symposium, thus emphasizing, among other things, the interest in 

 the current problems and latest accomplishments associated with physics of 

 fluids , ocean waves , and maneuverability and ocean platforms. Important 

 progress has been made in various aspects of ship maneuverability, and this 

 meeting served to stimulate further effort and to emphasize a relatively little 

 documented field of endeavor. The broad field of waves covers many aspects 

 of ship waves and wave resistance and ocean or wind- generated waves. Physics 

 of fluids covers many fundamental aspects of ship problems: cavitation, visco- 

 elastic flows, turbulence, and turbulent boimdary layers. 



The international flavor of these meetings continues to be an outstanding 

 feature and, in this case, has been enhanced by the large percentage of authors 

 and chairmen from foreign countries. 



The address of welcome by Dr. Davis and the speech opening the sym- 

 posium by Captain Melson more than adequately describe the background and 

 objectives of this meeting, thus leaving little more to be said other than to 

 express our gratitude to all those who contributed so much to the success of 

 this symposium. However, taking the liberty of speaking both for the Office 

 of Naval Research, as well as the international scientific community of hydro- 

 dynamicists, I should like once again to express our deepest appreciation to 

 Dr. J. P. Breslin,Mr. D. Savitsky,and Mr. J. S. Welker of the Davidson Lab- 

 oratory, Stevens Institute of Technology, and to Mr. P. Granville of the Office 

 of Naval Research for their outstanding efficiency and care in managing the 

 many varied aspects of this symposium. 



UA^ & 



RALPH D. COOPER 



Head, Fluid Dynamics Branch 



Office of Naval Research 



111 



