Experimental study on flow characteristic through flexible vegetation

• Main Authors: Ming-cheng Wu, 吳銘城
• Other Authors: Jhen-mou Lyu
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/93219510240102713463

碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 96 === In Taiwan area often have typhoon attracting during summer times. Typhoon brings abundant rainfall and the rainfall concentrates to the river, naturally washes out the main channel and the river high alluvion. When flood retreat, the exposed high alluvion can be widely used. Agriculture, plant and wetland, these places can increase zoology. On the other hand ,they baffle current of water flow. So this research focuses on different arrangement of flexible vegetation. An experiment set up to analyze the gradually varied flow through flexible vegetation. In this experiment including two parts, one is no plants at the central of the channel (group A) , and another is no plants at the side of the channel (group B), the density of plant group is 66 stem/ m2. All discharge in the test is 0.0357cms.Using side-looking ADV to measure the part above plants and main channel, and down-looking ADV to measure the part between two plants. Based on these measurement，we can analyze the flow characteristic and realize the discharge distribution at the experiments. After calculating the data, when flexible plant grow on the smooth channel, at the same plant density, about 50% of the discharge in the channel will be concentrated to the main channel, 40% of the discharge upon the plant group and the discharge above the plant group is less than 10%. In these two groups of experiments, the distribution of the discharge are almost the same , the error will prove in the article. On the other hand, there have circulation occurred at the transition zone between plants and main channel, this has shown momentum exchange in this area.