由於環保問題，震波/渦漩交互作用所引起噪音是工程師和科學家們所感興趣的問題。此現象發生在汽車引擎排氣管中或是震波在建築物內運動時。本文旨在研究震波繞射時所產生之渦漩與反射震波交互作用的流場結構。震波繞射分別經過九十度轉角與一百八十度轉角兩種情況，分別探討所形成的渦漩結構與特性及其噪音產生的機制。所採用的方法為加權基本不震盪法搭配有限體積法求解二維可壓縮尤拉方程式。首先驗證程式之正確性，計算結果並與現存實驗結果相比較，相較結果令人滿意。其次對震波繞射問題做探討，並且對不同入射震波馬赫數之繞射震波所引發渦漩生成，以及為了捕捉反射震波與渦漩交互作用所產生的環形聲波，本文採用陰影法、紋影法、全像干涉三種方法做詳盡的報導。本文發現當入射震波馬赫數的強度達到一定的程度之後，在流場中間部份的反射震波會有滯留現象產生，兩旁反射震波則受到渦漩的影響加速向上游前進，滯留反射震波之臨界入射震波馬赫數約為1.4。本文涵蓋二維與軸對稱之結果，吾人發現，當反射震波與渦漩交互作用時，軸對稱問題所引發之渦漩中心壓力提升低於所對應的二維問題。

In this study, the problem of a planar reflected shock/vortex interaction near an open-ended duct is considered. The reflected shock is developed after exiting the duct and impinging on a flat plate that is downstream of the duct. Two cases associated with the shock diffraction around the duct end are investigated for understanding the detailed flow structure and noise production due to the reflected shock/vortex interaction. One is a 90-degree diffraction; the other is a 180-degree diffraction. An Euler solver with a high-resolution scheme of weighted essential non-oscillation is used to study these complicated flow problems. The Euler solver is validated for the accuracy of numerical solutions with experimental data. For the study of the reflected shock/vortex interaction, the techniques of computational shadowgraph, schlieren image, and interferography are used. Detailed flow structures of reflected shock/vortex interactions are reported for different incident shock Mach numbers. An interesting result of a stagnant reflected shock wave downstream of the duct end is found for an incident shock Mach number equal to or greater than 1.4. For the incident shock Mach number below this critical value, the reflected shock will eventually enter the duct. Finally, the corresponding ring vortex is included for comparison with the planar case. It is found that the pressure increase at the vortex center due to the reflected shock in the axi-symmetric problem is less than that in the corresponding planar case .

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