在空蝕模型中有許多可調經驗係數的存在，其中控制空蝕強度的為蒸發及凝結係數，然而文獻中可以發現各學者即便用相同空蝕模型，所使用的蒸發、凝結係數卻不盡相同，這顯示係數的選取可能受到很多因素的影響，如幾何的改變、紊流模型選用的不同，都有可能造成係數選取的不同。此外，在空蝕模型中的係數若為有因次的，當流場中的特徵尺寸變動，這些可調參數可能就會造成空蝕模型產生無法保持動態相似的問題。一般來說，非穩態的空蝕流場對於係數的敏感性又比穩態流場來得高。在此研究中，將針對不同之空蝕模型透過使用不同的幾何，以分析蒸發及凝結係數的敏感度。並利用動態相似的概念，將係數全調整為無因次觀察這些係數的敏感度，希望在不同幾何、空蝕強度或是紊流模型之下，規範出係數之合理使用範圍。

The cavitation models are used to predict the dynamics of cavitation phenomenon. There are many tunable constants which is empirical-based in the cavitation models such as evaporation and condensation coefficient. Because of dynamic similarity issue, geometry change, turbulence models and other numerical details, there are various constants in different researches. In this paper, the dynamic similarity issue will be investigated and the sensitivity of the empirical constants and the interplay with turbulence models will be assessed by multiple steady attached and unsteady cloud cavitation problems in terms of experimental validations. The goal of this paper is to show the sensitivity and generality of the adjusted constants of different cavitation models.

審定書 i
摘要 ii
Abstract. iii
目錄 iv
表次 vi
圖次 vii
第一章 緒論 1
1.1 研究背景 1
1.2文獻回顧 3
1.2.1實驗 3
1.2.2空蝕模型 4
1.2.3紊流模型 9
1.3研究目的 11
第二章 研究方法 12
2.1 數學模型 12
2.2空蝕模型 13
2.3 紊流模型 17
2.4 數值方法及邊界條件 18
第三章 研究結果 19
3.1流場配置及網格測試 19
3.2 研究流程 22
3.3 Singhal 空蝕模型 25
3.4 Zwart空蝕模型 36
第四章 結論與建議 50

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