Abstract
Model experiment of Tsunami or seismic sea wave requires to satisfy the law of similitude. However it is generally im_??_ossible when the effect of viscosity is taken into consideration and it has been considered that this effect is a serious problem to the model experiment of Tsunami. This erroneous idea comes from the fact that we have been concerned only with the molecular viscosity of water of which coefficient of viscosity is considered to be equal in both cases of molecular and turbulent viscosity. In these cases, however, turbulent viscosity predominates the molecular viscosity and its coerficient for sea water is considerably larger than that of water in the model. Thus even when the viscosity is taken into consideration we can satisfy the law of similitude by adjusting the size of model adequately. Furthermore the author obtained a formula expressing the height of wave in a bay in the case of viscous fluid and compared it with that of ideal fluid. Details of the research will be found in English in the “Science Report of Tohoku University”, series 5, Vol. 2.
