取水施設の流入量に関する研究

This head work is the water-intake structure, by which irrigation water has been carried to the reservoir constructed in the other catchment basion. We always have intaken water from the river by this head work, even at the time of flood. To design such structure, we have to know the rerationship between the gate opening and the discharge of water or the discharge coefficient which varies widely according to the river water level. That orifice formula could be used in calculation to obtain the amount of discharged water from the gate has experimentally been confirmed by Toch, Honma and others. The discharge coefficient of the intake gate Cq is shown in its relationship to parameters expressing the gate geometry. Any agreement between actual gate discharge and Toch's experimental results could never be found when the gate geometry is different. Therefore, we can only obtain Cq value through a specific model study for a particular project. Specially in this intake mention should be made here to the fact that the loss of head Ф in the uniform flow sections upstreams and downstreams from the gate is ignored, and the value of Ф related to the Cq value. Relation between Cq and Ф can be obtained by the following equation using the Bernoulli's energay theorem, in which ψ. Ф are head loss parameters, Cq H1･H2 /√H12 (1+ψ) + H32 (Ф-l) and Cq value can be obtained by calculating head loss. On the other hand, if the systematic graphical representation of the relationship between the value q and the elements is obtained by the experimental measurements of hydraulic model tests, q-H1/h～H3/h, in which H1,H3 are the depths of flow in the upstream and downstream from the gates, should be considered applicable to the practical work and useful in checking up the experimental values with theoretical solution.