Wave Excitationless Ships Forms 



3. To bring the excitationless frequency into low-frequency range such as 

 ordinary wave encounter frequency, it will be necessary to make the underwa- 

 ter volume large enough in relation to the water plane area. The underwater 

 volume can be replaced by a flat plate which has the same amount of added mass 

 as the underwater body. 



4. Wave-damping also vanishes as the heaving force vanishes. Therefore, 

 it will be necessary to give damping other than wave-damping to a body to re- 

 duce heaving or pitching motion. 



5. In the case of a two-dimensional body, for a segment of unit length, 

 heaving force due to beam seas is almost equal to that due to longitudinal waves. 

 Therefore, strip method can be applied for three-dimensional bodies. It will 

 also be possible to apply the present technique to the pitching motion. 



6. It is also possible to extend this technique to the three-dimensional 

 problem. 



REFERENCES 



1. F.Ursell, "On the Rolling Motion of Cylinders in the Surface of a Fluid," 

 Quart. Journal of Mech. and Applied Math., Vol. II (1949) 



2. T. Hishida, "A Study on the Wave-Making Resistance for the Rolling of 

 Ships II," Journal of Zosen Kokai, Vol. 85 (1952) 



3. W. McLeod and T. Hsieh, "Experimental Investigation of Ursells Theory of 

 Wave Making by a Rolling Cylinder," Schiffstechnik Bd. 10 (1963) 



4. M. Bessho, "On the Wave-Free Distribution in the Oscillation Problem of 

 the Ship," Journal of Zosen Kiokai, Vol. 117 (1965) 



5. J. N. Newman, "The Exciting Force on Fixed Bodies in Waves," Journal of 

 Ship Research, Vol. 6 (1962) 



6. S. Motora, "Stripwise Calculation of Hydrodynamic Forces Due to Beam 

 Seas," Davidson Lab. Note No. 656 (1962), Journal of Ship Research, Vol. 8 

 (1964) 



7. J. R. Paulling and R. K. Richardson, "Measurement of Pressure, Forces, 

 and Radiating Waves for Cylinders Oscillating in a Free Surface," Report of 

 Institute of Eng. Research, Univ. Calif. (1962) 



8. W. Cummins, Trans, of Symposium on Ships and Waves Council on Wave 

 Research, SNAME (1954) 



9. Y. Yamamoto, "On the Oscillating Body under the Water Surface," Journal 

 of Zosen Kiokai, Vol. 77 (1955) 



10. F. Tasai, "On the Damping Force and Added Mass of Ship's Heaving and 

 Pitching," Journal of Zosen Kiokai, Vol. 105 (1959) 



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