境水道の水位変動に関する水理模型実験(1)

Abstract

This is a report of the preliminary test of hydraulic model experiment on theoscillation of the water level in Sakai Channel, which connects Nakaumi with MihoBay.First, in order to examine the scale effect, some experiments for semi-diurnaltide and 130 minutes oscillation are carried out under constant horizontal scale, 1/500, and five different distortions, that is, 2, 4, 6, 8, and 16. The term "distortion"means the ratio of Vertical scale to horizontal. As the result, it is found out thatthe scale effect seems rather large on the oscillation of longer period as semi-diurnaltide and very small on that of shorter period as 130 minutes oscillation. In spiteof the smaller reservoir and larger amplitude, the state of damping of amplitudein the channel with reservoir is similar to prototype when the distortion is 4.Then, I~I order to investigate the character of frequency response of the modelchannel, two series of experiments are carried out for sinusoidal waves of variousfrequencies, one is that for the channel with reservoir and the other withoutreservoir. After these experiments it is clarified that the character of frequencyresponse of the channel without reservoir is considerably different from that withreservoir, therefore the effect of the area of reservoir on the character of frequencyresponse is of much importance.