Similarity criteria for the distorted harbor models with movable beds

Abstract

ABSTRACT Almost all harbor models are distorted geometrically or in other ways when the model studies consist of the movement of the bottom sediment materials, since the horizontal dimension of such prototype is very large with respect to the vertical one and the laboratory facilities are limited. For the establishment of the model-similarity laws a mixed approach is used; The similarity conditions of a distorted harbor model with a movable bed are derived from the semi-empirical and theoretical equations resting partly on dimensional analysis and partly on deductions from dynamic equations. The degrees of distor tions or scale ratios are given by a system of criteria which con tains 10 independent scale ratios satisfying 9 equations. By choo sing the critical scale ratio in the system the other independent scale ratios satisfying several conditions defined by the equations of criteria, can be obtained. The proposed method requires the case of a negligable bottom slope, long waves of deep water, and of nearly spherical material of uniform size. Its application is given by se veral examples satisfying certain critical conditions for the scale ratios. - vi