| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
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| Research Abstract |
The purpose of this study is to develop a new drainpipe with vortex chamber in order to free from danger of engulfing the human body in the drain-port of swimming pool. The proposed drainpipe can control the suction force with the working of vortex flow. It is worthy of note that the control action is performed with water flow itself without any mechanical equipment. At first, the reduction effectiveness of the suction force was confirmed in experiment, and fundamental data concerning about flow property were obtained. Then, the author analyzed the effects of shape parameters of the vortex chamber, such as thickness of the chamber, diameter of discharge pipe, and so on, on the flow property. And, theoretical model of flow in the drainpipe was also investigated.
Results obtained here are as follows :
1.It was evident that the suction force of the proposed drainpipe can be reduced drastically compared with usual one. In addition to that, the flow resistance of the drainpipe was smaller than the value of usual drainpipe.
2.The point of design for drainpipe is to reduce the suction force at stick state. And, it is also important that the flow resistance should be small in normal flow state. For those purpose, the appropriate value of the ratio of discharge pipe diameter to vortex chamber one was nearly 0.22. And the ratio of chamber thickness to chamber diameter showed good tendency at about 0.3.
3.The analytical model of the flow in the vortex chamber consists the free vortex in the outer area and forced vortex in the central area. And the mode can analyze the effect of the vapor cavity generated at the center of vortex.
4.The author investigated the swimming pool accident happened in 2002, and obtained data concerning with the shape of drain-port and the specification of circulation pump.
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