On the Static Water Surface Impact due to Rainfall

• Main Authors: Ching, Hung-hen, 簡宏亨
• Other Authors: Liu Chung-ling, Wu Jin
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/48568289447748841282

碩士 === 國立成功大學 === 水利及海洋工程學系 === 86 === A rainfall generator that produces uniformly distributed rain is used in these experiments. These studies use a High Frame Rate Area Scan Digital Camera to take photographs of water surface after raindrops impact, and the image technique analyze the height of crown water column and the process which develop. The result of experiments shows that the height of water column increasesas the average size of raindrops increases. However, the average size of raindrops up to 4mm, the height of water column will not increase. The resultsof difference between single rain drop and group raindrop which impact on the static water surface reach five points. (1) When group raindrop impact on the static water surface and happen splash and cavity, it can not sure to form thecrown water column. (2) The crown water column has inclined direction upward. (3) The width of crown water column changes from thick to thin in the process which develop. (4) No phenomenon of the crown coalescence can be seen. (5) Theheight of crown water column grows not going with a deep cavity. Thephenomenons are more conspicuous when the average size of raindrops is larger.On the other hand, above phenomenons of group raindrop impact on the staticwater surface are more significantwhen the wave of the water surface grows.