船型試験水槽で発生させたTransient Water Waveの特性について
1968 年 1968 巻 124 号 p. 113-124
詳細
1968 年 1968 巻 124 号 p. 113-124
Testing ship models in transient water waves is considered to one of the useful methods which measures or predicts the ship frequency response functions in waves. On ship-wave-systems, testing or calculating techniques of transient water waves have been discussed by some authors. In this paper, the properties of wave-wave system and wavemaker-wave system in transient water waves are investigated by experiments and analysises.
Transient water waves used in this experiments are classified two groups. First group are called concentrating transient waves, these waves are generated in conditions that the wave frequency are uniformly swept from high to low. The concentrating transient wave produces the pulsive water wave at some position of the model basin. Second group are called diffusing transient waves, these waves are formed in case that wave frequency are inversely swept from low to high.
In consequence of the present investigation, next properties on these transient water waves ware obtained.
1) So-called linear response system can be applied to next cases.
a). diffusing transient waves, b). concentrating transient waves before the concentration, c). wavemaker-wave systems in the cases a) & b).
2) Concentrating transient waves after the concentration can not be explained by the linear response system.
3) wavemaker-wave system are also considered to one of the linear system. But the phase lag between motions of the wavemaker and the generating waves at the position of wavemaker is complex. The amplitude ratio calculated from the transient experiments coincides with that measured from regular wave tests.
