本研究利用氣動力數值模擬計算固態火箭發動機噴焰熱流場之熱負荷，嘗試耦合適當的熱防護材料燒蝕邊界條件，進行所需耦合燒蝕邊界條件的外掛程式開發。初步燒蝕物理模型假設是熱防護材料因熔化相變化而燒蝕，首先當衝擊壁面上的熱邊界條件是等溫壁面 (本研究設定為銅熔點溫度1358K)下，計算火箭噴焰對於衝擊面的熱通量，假設進入壁面之熱通量部分由擋板沿厚度方向熱傳，剩餘的熱通量全部用於熔化所需要相變化潛熱下計算衝擊面的燒蝕退縮量後，利用動網格移動衝擊面進行耦合燒蝕邊界條件的模擬計算；其次為更接近真實情況，本研究考慮衝擊壁面初始溫度為常溫下，利用一維及一維/二維暫態熱傳進行壁面升溫計算，當壁面溫度達到熔點時再進行相變化燒蝕，目前已初步完成及驗證上述之耦合燒蝕邊界條件的外掛程式開發。最後在固態火箭發動機中，粒子在燃料中約佔有16%的比重，若忽略粒子效應相則會與實際有所偏差，當加入粒子時，高動能及高溫粒子會對於衝擊壁面除了熱燒蝕效應外，還有機械能沖蝕效應，因此本研究針對雙相流流場中對於衝擊壁面之燒/沖蝕進行評估分析，考慮粒子效應後研究結果發現，雙相流於衝擊擋板的熱通量明顯高於單相氣流，另外本研究使用Oka沖蝕模型計算粒子對於衝擊壁面之累加沖蝕厚度，並初步完成外掛程式開發及驗證。

In this study, computational fluid dynamics (CFD) coupled with thermal erosion model is used to simulate the thermal erosion process of supersonic jet impinging on thermal protection material with aims to develop the suitable user defined function (UDF) for thermal boundary condition in Thermal Protection Material (TPM) ablation problem. The preliminary ablation physical model assumes that the thermal protection material is ablated by phase change latent heat due to melting processes, and the boundary condition on the impinge surface is initially assumed as the isothermal wall condition at material melting point (ex, the copper melting point temperature 1358K), and calculate the heat flux of the supersonic jet on the impinging surface. The heat flux on the surface is used to calculate the ablation thickness of the impinge surface under the latent heat phase change. In addition to isothermal wall condition, in order to get closer to the real situation. This study considers that the initial condition of the impinge surface is at room temperature, and uses the one-dimensional and one-dimensional/two-dimensional transient heat transfer to calculate the rise of the impinge surface temperature. When the impinge surface reaches the melting point, phase change ablation will be performed. Finally, the actual solid-propellant rocket alumina particles (about 16% of the plume) is considered in the present CFD model. The results show the thermal loading effects of particles on the impinge surface is very significant. If the particle effects is ignored, the wall heat flux is one order of magnitude less than the results with the particle thermal loading consideration. Therefore, high temperature particles will affect the impinge surface when the particles are taken into account. In addition to the thermal erosion effects, there are also the mechanical erosion effects on the impinging surface. Therefore, this study will also evaluate and analyze the ablation/erosion of the impinging surface in the two-phase flow.

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