本實驗採用液滴自由落下方式撞擊親水性平板，並分為雙顆液滴撞擊冷板以及單顆液滴撞擊熱板。其中雙顆液滴撞擊主要以雙顆不同間距 (Δt)之液滴撞擊不鏽鋼板和石英板並探討改變間距對撞擊行為的影響而液滴撞擊速度 固定控制在 2.75 ± 0.05 m/s，韋伯數約為 98。 根據撞擊兩種平板的結果間距改變對撞擊行為影響甚大。其結果顯示當尾隨液滴追撞正擴展至最大擴展直徑的領導液滴時， 追撞後液膜所達到之最大擴展直徑 (dw*,max) 為最大值 。另外，本實驗也針對撞擊瞬間所產生的環狀液膜和撞擊後的震盪幅度進行分析 ，並發現在尾隨液滴撞擊回縮中之領導液滴時，有最大振幅發生 。 最後， 在比較雙顆小液滴 (di = 930 μm, Δt = 0.4 ms) 和單顆大液滴 (di = 1170 μm) 撞擊平板的條件下，結果顯示兩者之無因次化擴展直徑變化幾乎一致，其表示擴展直徑的變化主要由液滴體積與撞擊速度大小所主導。
在單顆液滴撞擊熱板中，撞擊面板同樣採用不鏽鋼和石英熱板 ，並將液滴 We分別控制在大約 50, 98, 150，主要探討液滴撞擊不同板溫之平板的撞擊行為變化 。 實驗顯示，液滴撞擊板溫在 25° ~ 260°C的平板上之撞擊行為共可分類為三種型態分別為 deposition, deposition (bubbling), deposition (atomizing)。實驗過程可觀察到隨著 We的增加，液滴撞擊出現 deposition (atomizing)的臨界值會隨之下降。而從液滴擴展過程的分析可發現 ，液滴從接觸平板後到最大擴展直徑的歷程時間受到 We和板溫的影響非常微小 ，但在撞擊後所達到的最大擴展直徑則隨著 We和板溫的增加而增加。 另一方面，實驗顯示在撞擊石英板板溫約 100°C和撞擊不鏽鋼板板溫約 100 ~ 150°C，液滴在回縮過程中出現二次擴展的過渡現象，其擴展的範圍隨著板溫增加而逐漸減小。

The experiment is conducted using the free-falling drops impinging onto the hydrophilic plates, and is classified into two parts. First part mainly investigates two water drops with the specific time interval (Δt) impacting the stainless-steel and quartz surfaces at the room temperature. The objective has focused specially on the influence of varying the Δt on the impact behaviors of the drop. Notably, the impact velocity of the drops is controlled in 2.75 ± 0.05 m/s. From the results, it shows that the maximum value of the maximum spreading diameter (dw*,max) occurs in the case that the trailing drop collides with the leading drop which just spread to the maximum spreading. Also, the results indicate that the circular liquid film that occurred instantly at the impact moment and the oscillation amplitude after the drop impact are also significantly influenced by varying the Δt. The results show that the maximum amplitude occurs in the case that the trailing drop impact the leading drop which was retracting the center of the film. In the comparison of the two special cases between a single drop (di = 1170 μm) and two drops (di = 930 μm, Δt = 0.4 ms), the evolution of the spreading diameter (dw*) is almost the same, which indicates that the evolution of the dw* is primarily governed by the total volume of the drop and the impacted velocity.
Another part of experiment studied a water drop impinging on the heated stainless-steel and quartz surfaces with various surface temperature (Tw). The We of the drop are controlled in 50, 98, 150. The results showed that the impact behaviors of drop impact on the heated surface at Tw = 25° ~ 260°C could be categorized into three types: (I) deposition, (II) deposition (bubbling), (III) deposition (atomizing). It indicates that the threshold from type II to type III decreased with the increases in We. In the analysis of the spreading process, the result show that the influence of varying the We and Tw on the elapsed time for the drop spreading to dw*,max is negligible. However, the value of the maximum dw*,max increases with the increases in We and Tw. On the other hand, the transition phenomenon during the drop retraction, the secondly spreading, is performed in the case that the drop impinges on a quartz surface at Tw = 100°C and a stainless-steel surface at Tw = 100 ~ 150°C. As the Tw increasing, the extent of the secondly spreading decrease gradually.

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