頁籤選單縮合
題 名 | Topological Flow Structures of Annular Swirling Jets |
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作 者 | Tsai,Feng Chin; Huang,Rong Fung; | 書刊名 | The Chinese Journal of Mechanics |
卷 期 | 17:3 2001.09[民90.09] |
頁 次 | 頁131-138 |
分類號 | 440.137 |
關鍵詞 | Swirling wake; Vortex breakdown; Recirculation bubble; |
語 文 | 英文(English) |
英文摘要 | The effects of blockage and swirl on the macro flow structures of the annular jet past a circular disc are experimentally studied through the time-averaged streamline patterns. In the blockage-effect regime, the flows present multiple modes, single bubble, dual rings, vortex breakdown, and triple rings, in different regimes of blockage ratio and swirl number. The topological models of the flow structures are proposed and discussed according to the measured flow fields to manifest the complex flow structures. The single bubble is a closed recirculation bubble with a stagnation point on the central axis. The dual-ring flow is an open-top recirculsation zone, in which a pair of counter-rotating vortex rings exists in the near wake. The fluids in the dual rings are expelled downstream through a central jet-like swirling flow. A vortex breakdown may occur in the central jet-like swirling flow if the exit swirl number exceeds critical values. When the vortex breakdown interacts with the dual rings, a complex triple-ring flow structure forms. Axial distributions of the local swirl umber are presented and discussed. The local swirl number increases with the increase of the exit swirl number and attains the mzximum in the dual-ring mode. At large exit swirl numbers where the vortex breakdown occurs, the local swirl number decrease drastically to a low value. |
本系統中英文摘要資訊取自各篇刊載內容。