建議

穴蝕氣泡破裂所產生的流場，甚為複雜，在實驗過程中有許多變因 與現象並未研究，下列建議供未來進一步研究之參考。

1. 本研究之試驗試管為單一管徑，若能有不同管徑之變化，可以比較其 相互作用之差異性。本研究為水平試管的探討，未來可以改變試管為 傾斜或垂直，探討不同方向上的流場狀況。本研究衝擊彈簧打入方向 為上下的垂直走向，因此震波是由垂直方向傳遞至管內，如衝擊彈簧 能與內管保持平行，即兩者保持水平方向應會降低管內的壓力消耗；

另應注意平台震動的問題，因氣泡非常小，易受外力影響。

2. 本研究在試管末端無固體邊界，後續可加上固體邊界去探討氣泡破裂 時在固體邊界上所發生的流場現象。壓力的測定只來自於尾端壓力感 測器的量測，如壓力感測器安裝於管壁上，可得到邊壁受壓力情形並 得到更多數據，且因更靠近穴蝕氣泡而能量到氣泡破裂造成強大壓 力。

3. 在定量實驗上，控制好光頁的厚度及角度以避免PIV影像過度曝光；

另質點顆粒數量多寡，是影像清晰度的關鍵，影像解析度高所計算出 的相關數據才有使用的價值。可將本研究之PIV量測方法提升為CPIV 之量測方法，提供彩色品質更好的影像，進行氣泡破裂過程之瞬間流 場、渦度場與壓力場等研究。在PIV演算時，折射產生於氣泡表面附 近之亮度帶區域，視為與一般影像亮度值分佈一樣，可用於互相關函 數之質點位移分析。改善光頁厚度與顯影質點更細化之搭配，可供PIV 在後續研究發展得到改善，以期更能呈現於中央截面上之氣泡破裂過 程。

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附錄一 Kelvin–Helmholtz instability 定理

由於各相流之間的剪應力作用使得不同流相因加速度差異產生不穩定 性，此現象稱為 Kelvin - Helmholtz 不穩定流動，產生流體層流流況穩定逐 漸轉化為紊流。因此，區分無旋運動和有旋運動是研究無粘流動必須遵循 的基本原則，Kelvin 速度環量守恆定理和 Helmholtz 關於渦量守恆的幾個定 理，為研究氣-液流動提供了重要的理論基礎。

分析說明：

分析說明：