極音速載具為現今各國主力發展之一，而在極音速環境下所帶來的嚴峻挑戰也隨之而來，載具表面所承受阻力及熱負載成為一大關鍵。透過於鈍體前方添加入尖釘是一種簡單且有效降低阻力及熱負載的方法，故本研究使用數值模擬方式，針對具有尖釘之鈍體進行阻力及熱負載的評估，有利於未來設計極音速之外型及熱防護材料之依據。
本研究在流場模型驗證中，將模擬的密度圖、鈍體上之壓力分布及熱通量分布趨勢與實驗結果進行比對驗證，以確認所建置模型之可靠性。接著本研究透過改變尖釘的幾何外型，從中可以看出流場結構差異。研究結果顯示，增加尖釘之長度及角度，會增加有效體之形狀，有利於降低壁面壓力及熱負載。並且每當增加尖釘長度時，所降低之壓力及熱通量的差距也會逐漸縮小。而在建立化學模型之驗證分析當中，於流場中可觀測到因高溫產生之化學效應，氣體產生大量解離之現象，導致震波與鈍體間之溫度流場會隨之下降。而所模擬結果之流場現象及物理性質與實驗及文獻模擬結果相近，驗證本研究化學模型之有效性。最後，透過在不同馬赫數的模擬研究當中，可得出隨著馬赫數增加，造成整體流場所承受之壓力及熱負載更大之外，也可觀測到本研究在馬赫數13狀態下會產生顯著的化學效應，相對而言6.8及10馬赫狀態下化學效應並不顯著。並且透過熱通量分布圖可觀測到考慮化學效應後，熱通量會產生些許差距，這也說明在相同流場條件下，若要考慮更高之馬赫數，化學效應之重要性也會隨之提高。

Today, hypersonic vehicles are one of the main development projects of various countries. Nevertheless, the severe challenges posed by the hypersonic environment also need to be faced. The resistance and heat load that the surface of the carrier needs to bear becomes a key point in the design. It is known that adding Spike in front of the blunt body is a simple and effective way to reduce drag and heat load. This study uses numerical simulation to evaluate the resistance and thermal load of a blunt body with a Spike.
In the verification of the flow field model, this study compared the simulation results with the experimental values to confirm the reliability of the model. Then, this study observes the difference between the flow field structures through the change of the geometric shape of the Spike. The research results show that increasing the length and angle of the Spike will increase the shape of the effective body, which is beneficial to reduce the wall pressure and thermal load. And whenever the length of the Spike increases, the variation of pressure difference and heat flux difference will gradually decrease. Finally, through the simulation studies of different Mach numbers, it can be concluded that as the Mach number increases, the pressure and heat load on the overall flow field will be greater. In addition, significant chemical effects can also be observed in this study at Mach 13. Relatively speaking, in the state of Mach number 6.8 and 10, the chemical effect is not significant. Through the heat flux distribution diagram, it can also be observed that after considering the chemical effect, there will be a slight difference in the heat flux. This situation also shows that under the same flow field conditions, if a higher Mach number is considered, the representative importance of chemical effects will also increase accordingly.

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