臺灣博碩士論文加值系統

本研究旨在以液滴撞擊金屬鈑及衝擊火苗觀察其撞擊後之動態行為及火苗壓制，在液滴撞擊金屬鈑部分是以高速攝影及實驗量測，有系統的研究液滴衝擊一壁面時，其液滴流動性質與壁面表面性質對液滴之流體動力行為之影響；實驗參數主要為液滴衝擊前之雷諾數、韋伯數、表面材質(熱擴散係數)以及表面溫度等包含液滴流動性質與壁面特性。本研究採用兩種具有不同流體性質的工作流體；分別為純水與酒精，兩種具有不同熱物理性質之靶鈑；分別為鋼與銅。有關於液滴之流體動力行為的特性，主要是觀察其飛濺，延展或者反彈之流體動力現象；另外在飛濺部份主要還包含觀察其碎裂型態。
第二部分則是有關液滴對火苗抑制或熄滅部分，以可視化攝影的方式觀察液滴對煤油燈芯火苗抑制現象，期望建立本土之水霧滅火效果之數據庫，其主要內容為以實驗量測及放大攝影，觀察相同顆粒大小之液滴流，改變實驗操作之參數（例如流量、液滴顆粒大小、火苗大小等）觀察火苗抑制與滅火效果。實驗技巧主要採用電子耦合裝置(CCD)之相機配合放大鏡頭進行顯微或放大攝影。實驗結果顯示火燄被熄滅之原因可能肇因於液滴對火苗周圍空冷卻及干擾，而此一效應與液滴大小、頻率與衝擊火苗速度有關。

The objective of the study is to observe phenomenon of impacted metal surface and fire suppression and fire extinguishment by droplet impingement. The first part is to observe phenomenon of impacted metal surface by droplet impingement. The objective of the present work is systematically to study the effects of flow property and surface characteristic on the fluid dynamic by employing the high-speed CCD camera techniques and experimental measurements. The experimental work is unique in that the droplet impact factor is systematically rated in different non-dimensional numbers and parameters such as Reynolds number, Weber number. The parameter study includes the effects of the Reynolds number, Weber number, surface material (thermal diffusivity) and temperature. The dynamic behavior of droplet impingement will be mainly characterized by the splash, spread, rebound.
The second objective of the study is to investigate the phenomenon of fire suppression of a kerosene lamp by water droplet impinging on the flame. The macro- and micro-photographic was used in this experimental work to obtain quantitative data. The main part of the experimental setup is the CCD camera assembled with micro- or macro-photographic. A monodisperse water droplet generator was used to generate a droplet stream. The stream was used to extinguishing the flame. The concerned parameters were flow rate, droplet size and flame size etc. The results show that the suppression of a flame without touching the lamp core could be related to the droplet size, frequency and velocity, which could cool down the flame and interfere in the structure of the flame.

1.緒論 1
1.1 前言 1
1.2 文獻回顧-液滴撞擊金屬鈑之實驗研究 2
1.3 文獻回顧-液滴衝擊火苗之實驗研究 5
1.4 研究之動機 8
1.5 研究之目標 9
1.6 研究主要貢獻 10
1.7 論文架構 10
2.液滴撞擊金屬鈑之實驗研究 12
2.1 研究構想 12
2.2 研究方法 12
2.2.1 誤差分析 14
2.3 結果與討論 14
2.3.1 壁面溫度對液滴衝擊壁面流體動力行為的影響 32
2.3.2 靶鈑材質對撞擊型態分佈的影響 37
2.3.3 流體性質對液滴撞擊型態分佈的影響 37
2.3.4 液滴撞擊速度影響 39
2.3.5 靶鈑材質對液滴衝擊壁面最大延展量的影響 40
2.3.6 流體性質對液滴衝擊壁面最大延展量的影響 43
2.4 結論 44
3.液滴衝擊火苗之實驗研究 49
3.1 研究構想 49
3.2 研究方法 49
3.2.1 誤差分析 51
3.3 結果與討論 51
3.3.1 大液滴對火苗(燄)抑制的實驗 51
3.3.2 微小液滴對火苗(燄)抑制的實驗 52
3.3.3 液滴流之流動特性對火苗熄滅效應之實驗 54
3.3.4 液滴流之液滴大小對火苗熄滅效應之影響 55
3.3.5 有效水流通量對火苗熄滅效應之影響 56
3.4 結論 57
4.總結與未來展望 59
4.1 總結 59
4.2 未來展望 59
參考文獻 113
自 傳 118

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