穿音速流通過機翼釋放具鰭片彈體之參數效應數值研究

Numerical Study of Parametric Effects for Transonic Flows around a Store with Fins Released from a Wing

楊世英(Shih-Ying Yang) ； 連振傑(Chen-Chieh Line) ； 廖偉廷(Wei-Ting Liao)

《航空太空及民航學刊.系列B》 44卷2期 (2012/12) Pp. 99-108

https://doi.org/10.6124/12-0803-700

摘要

本文使用商用軟體CFD-RC FASTRAN研究穿音速流通過機翼釋放具鰭片彈體之參數效應，在卡式座標下求解三維非穩態歐拉方程式，採用雙區塊Chimera網格系統，不同區塊網格系統重疊部分相互自動傳遞資訊，彈體重心瞬間軌跡與翻滾、俯仰、偏航角度、向下速度、俯仰率計算結果與實驗值比較後，得知趨勢相當接近，驗證本文計算的正確性，進而改變流場馬赫數、前後施力同時倍增、僅前施力倍增與飛行攻角等四種參數值以探討分離彈體非穩態物理現象。欲增加彈體重心向後移動量可增加馬赫數、前後施力同時增加或讓飛行攻角、僅前施力變小。欲讓彈體重心往翼尖方向偏移可將馬赫數提高至1.2、增加飛行攻角、前後施力同時增加。在彈體姿態部分，以駕駛者角度來看，欲增加順時針翻滾角可讓馬赫數增加或讓攻角變小。

關鍵字

彈體 ； 分離 ； 歐拉 ； 參數效應

並列摘要

In this article, the commercial software CFD-RC FASTRAN is applied to study the parametric effects of transonic flows around a store with fins released from a wing. The three-dimensional, unsteady Euler equations are solved in the Cartesian coordinate. The Chimera two-block grid system is utilized, and grid communication among two blocks are automatically implemented. After comparing the calculated instantaneous trajectory of center of gravity of store, angles of roll, pitch and yaw, downward velocity and pitching rate with those of experimental data, the satisfactory agreement is achieved. The accuracy of the present calculation is validated. Then, computations of different values of Mach number, both forward and rearward forces applied on the store, single forward force applied on the store, and angle of attack are carried out to investigate the unsteady physical phenomena of separated store. The position of center of gravity of store will be moved longitudinally backward if the Mach number, both forward and rearward forces applied on the store are increased, or single forward force applied on the store and angle of attack are reduced. As for the lateral direction, it will be moved toward the wingtip if the Mach number is raised up to 1.2 or the angle of attack, and both forward and rearward forces applied on the store are increased. Regarding the attitude of store, the angle of clockwise roll will be increased in the pilot's view if the Mach number is increased, or angle of attack is decreased.

並列關鍵字

Store ； Separation ； Euler ； Parametric effects

參考文獻

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