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題 名 | 多維向量推力噴嘴動態性能之數值研究=Numerical Investigation of the Dynamic Performance of the Multi-Dimensional Vectored Thrust Nozzle |
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作 者 | 戴昌賢; 厲復霖; 苗志銘; 孫維新; | 書刊名 | 力學 |
卷 期 | 15:1 1999.06[民88.06] |
頁 次 | 頁13-23 |
分類號 | 447.5533 |
關鍵詞 | 向量噴嘴; 動態格點; 側壁長度; 偏折角; Vectored thrust nozzle; Moving grid; Side wall length; Deflection angle; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究之主要目的在於利用數值方法,廣泛的探討向量噴嘴在動態狀況下推力之 響應。截至目前為止,不論是實驗或是數值方法,皆只針對某些特定中度的偏折角加以計算 , 因此本研究嘗試對此進行深入之研究。 研究方式係採用上風 TVD ( Total Variation Deminishing )數值法以求解無黏性 Euler 方程組,在空間通量計算方面, 採用人工耗散 項最小的 Roe's 算則,並搭配 Kappa 高階 MUSCL 算則; 在時間積分計算方面,則採用具 二階精度的 Hancock 法則進行時間積分,並配合動態格點技巧, 成功模擬二維向量噴嘴之 內部流場現象,以及向量噴嘴之動態性能。並將此數值方法加以推廣,延伸至三種不同側壁 長度之向量噴嘴三維流場計算方面。將數值模擬結果與實驗值相比對,可確定此數值方法之 可靠性並可引為設計上一有效之參考工具。同時發現,在出口速度為超音速的條件下,噴嘴 之內部流場特性只與出口面積比及偏折角度有關,與外界流場的變化並無直接的關連性,在 動態性能模擬上,則成功地觀測到推力隨偏折角度改變之歷程圖。此外,在三維流場計算方 面,不同的側板長度會造成不同程度的推力損耗表現。基本上,在本研究範疇中發現推力損 耗值與側板長度成正比例之關係。 |
英文摘要 | The aim of present study is to investigate both the steady-state and dynamic deflection angle effect on the output thrust of the vectored thrust nozzle with numerical method. In the literature, only a few experimental of numerical approaches on the behavior of vectored thrust nozzle with specified deflection angle had been analyzed. A deeply insight into the dynamic behavior of nozzle with different deflection angles is achieved. For simulating this complex problem, a finite-volume numerical code with TVD upwind method is adopted to solve the multi-dimensional Euler Equations. In spatial discretization, the least artificial viscous Roe's solver with high-order kappa MUSCL interpolation is used. In temporal discretization, the second-order explicit Hancock method is employed for time integration. Those methods coupled with dynamic grid generation technique show a great success in simulating the multi-dimensional inside and outside flow fields of the steady and dynamic vectored thrust nozzle. Moreover, the effect of side wall length to the thrust of three-dimensional vectored nozzle is also concerned. The present developed code can be sensed as an effective tool in design stage, as compared with present numerical results with published experimental data. For steady-state cases with supersonic outlet conditions. the prediction results show that the performance of the vectored nozzle is strongly related to the inlet-outlet area ratio and deflection angle. The outside flow field exhibits less effect on the performance. For cases of dynamic modeling, the time history of deflection angle wdth output thrust can be obviously observed from predicted results. For the three-dimensional simulations, tested vectored nozzle with different length of the side wall will induce different thrust loss. Basically, the shorter of the side wall length, the more thrust loss for the vectored nozzle. |
本系統中英文摘要資訊取自各篇刊載內容。