RECENT RESEARCH ON SHIP WAVES 



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J. N. Newman "^ '^'^ ^\oa<j 



Massachusetts Institute of Technology 

 Cambridge 3 Massachusetts 



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ABSTRACT 



This paper is concerned with various aspects of the 

 far-field wave pattern generated by a ship or other 

 moving body in steady translation. Section II contains 

 a brief derivation of the classical Kelvin wave pattern, 

 based upon linear inviscid wave theory. In Section III 

 full-scale aerial photographs are presented for the 

 waves generated by the Ferry Boat UNCATENA, and 

 compared both with the theory and with photographic 

 observations of a small scale model of the same vessel. 

 In Section IV we discuss a towing tank experiment, 

 designed to compare the waves generated by a "wavy 

 wall" with the nonlinear theory for this hull form. 

 Finally, in Section V, a third-order solution is out- 

 lined for the Kelvin wave system, which indicates the 

 occurrence of a nonlinear instability on the cusp line. 



I. INTRODUCTION 



Ship waves are intriguing from several viewpoints. To the 

 observer of a moving vessel, either layman or professional, they 

 are a fascinating pattern on the free surface --in otherwise calm 

 water one might, in fact, regard them as a thing of beauty. To the 

 naval architect they are of primary interest as a source of energy 

 radiation, and hence of wave drag on the vessel. More generally, 

 to ship hydrodynamicists of all disciplines, they are a source of 

 complication, interacting with, and affecting the boundary conditions 

 of, such fields as viscous drag, propeller-hull interactions, sea- 

 keeping, and maneuverability. To a naval vessel ship waves are a 

 possible source of detection, visible for hundreds of wavelengths or 

 ship lengths downstream and to each side of the vessel's track. 

 Similarly, to the operators of all types of vessels, they are a source 

 of damage to property and of personal injury to persons, in or be- 

 neath the water surface, or on the shoreline. And, to the theoretical 

 hydrodynamicist, they are the source of seemingly endless challenges, 

 both analytical and computational. 



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