Development of facilities for Control of pack ice movement and their design method

在本研究项目中，我们得到了以下结果：a)得到了从形阻力分量中分离出来的剪切力系数。在冰堵塞的情况下，当l/H （l：浮冰长度，H：冰厚）大于450时，形式阻力可以忽略不计，因为它小于剪切力的1%。b)通过观察在Saroma泻湖,当浮冰是完全被困在冰热潮中,分离的液体力作用在浮冰上通过冰的浮冰传播繁荣,和其余的液体由于拱形的浮冰,法案固定structures.c)两种类型的冰繁荣(水槽和浮子式冰繁荣和推翻类型冰繁荣)是在这个项目中,他们能够控制浮冰的运动。d)传统的冰栏和新型的冰栏能够控制易碎冰的移动。e)模拟了三种不同条件下的缺陷情况：泻湖不结冰、泻湖结冰、泻湖结冰并冰栏结冰。当形成冰塞时，一个循环后的缺陷率降低到无冰表面条件下的70%。冰塞似乎阻碍了水的交换。f)精度发展了三维流体运动的高精度数值模拟方法，并将该方法应用于结构附近的流体运动，具有足够的精度。g)利用EMMA估算地下水河水流量，预测农区河水NO3-N浓度。

In this research project, we obtained the following results :a) The coefficient of shearing force separated form the component of form drag force is obtained. In the case of ice jam, the form drag force can be ignored when l/H (l : length of ice floes, H : ice thickness) is mare than 450 because it is lero than 1% of the shearing force.b) Through the observation at Saroma lagoon, when ice floes are completely trapped in the ice boom, apart of the fluid force acting on the ice floes is transmitted via the ice floes to the ice boom, and the remainder of the fluid force due to arching of the ice floes, act the fixed structures.c) Two typed of ice booms (sink and float type ice boom and overturning type ice boom) were developed in this project, and they were able to control the movement of ice floes.d) Traditional type ice boom and newly developed ice booms were able to control the movement of fragile ice.e) Flaw conditions were simulated for three different conditions : no freezing on lagoon, lagoon frozen over, and lagoon frozen over and ice jam at ice boom. When an ice jam forms, the flaw rate after one cycle decreases to 70% of that under the condition of ice-free surface. The ice jam seems to hinder water exchange.f) Accuracy the method of high accuracy numerical simulation for the three dimensional fluid motion was developed and the method was applied to the fluid motion near structure with sufficient accuracy.g) River flow derived from ground water was estimated from EMMA to predict NO3-N concentration in the river water in the agricultural region.