本研究針對單/兩相流衝擊流流場對材料之熱燒蝕進行分析，對強耦合單/兩相衝擊流對銅板燒蝕模擬建立熔化模型，利用Fluent內建之固化/熔化模型進行材料燒蝕計算。當銅板達到1358K並吸收相變化潛熱後搭配外掛程式控制燒蝕邊界動網格退縮，使用流體域之時間尺度來同時直接求解流場、固體熱傳以及邊界燒蝕退縮，強耦合算法為最準確，但同時其計算成本也是相當高。對於實際工程應用而言，不僅僅需要符合工程要求，還需滿足其他條件如成本及可行性等。
在考慮高昂計算成本及可行性的條件下，本研究提出弱耦合算法來彌補強耦合昂貴計算成本的弱點，所謂弱耦合算法可以以較少的計算成本來分別對不同計算域使用不同時間尺度大小求解流場與固體熱傳，故本文也針對在單/兩相衝擊流對銅板燒蝕模擬方面建立三種弱耦合燒蝕方式的熔化模型，並且都加入燒蝕外掛程式以增加模型的靈活度，討論各種燒蝕模型之特性，每種熔化燒蝕模型都有其各自代表的物理機制，選擇合適的模型是模擬成功的關鍵。
本文將探討強/弱耦合之計算成本、單/兩相之流場熱負載影響及其貢獻度分析、單/多粒徑對熱通量及燒蝕影響之討論、熱負載在燒蝕退縮平/凹面上之敏感度分析、各種熔化模型之優缺點及燒蝕耦合時間尺度建議分析。本文Method 3模型考慮衝擊凹面後的各種效應，將會與實驗情況接近，而模擬結果會與實驗交互驗證以確保模擬的準確性及其應用價值。

Previous literatures show that the computational cost of supersonic two phase flow is very high, which is caused by the small time step size of the flow. First of all, considering many order of magnitude disparity of time scales between supersonic flow and structure heat transfer, three different weak coupling methods are proposed to simulate the thermal ablation process of supersonic jet impinging on a thermal protection material (TPM) in this study. The weak coupling method is found to provide significant computational savings by using different time scale sizes for fluid and solid domains. Then, this study also develops user-defined function (UDF) for boundary ablation dynamic mesh. Since there are many factors that affect thermal ablation, this study investigates the contribution of thermal loading in single/two phase flow, particle sizes, particle trajectory, coupling time scale and wall surface profiles due to thermal ablation. Numerical results show that particle heat flux is the main parameter that determines the magnitude of the ablation thickness, 80% of the total heat flux is contributed by particle impinging. Moreover, when selecting coupling time scale, the coupling time step 0.2 second is suggested in this this study. Furthermore, Method 3 model in this thesis considers a variety of effects after the particles impact the concave surface, which is expected to be close agreement with the experimental findings, and the simulation results will be validated with the experiments to ensure the its accuracy.

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