頁籤選單縮合
題 名 | Influence of the Horizontal Top Plate on Cavity Shear Flow=水平上蓋平板對空穴剪力流特性之影響 |
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作 者 | 郭正雄; 黃士豪; | 書刊名 | 中國機械工程學刊 |
卷 期 | 19:2 1998.04[民87.04] |
頁 次 | 頁135-147 |
分類號 | 440.137 |
關鍵詞 | 水平上蓋平板; 空穴剪力流; Cavity flows; Self-sustaining oscillations; Shear layer; |
語 文 | 英文(English) |
英文摘要 | 本研究是以實驗方法探討外加水平上蓋平板對空穴剪力流特性之影響。探討之參 數包括平板之前緣與空穴之相對位置 (-1.0 < X0/L <2.0) 平板和空穴之高度 ( 1.2< H/D <2.8) 以及雷諾數( 82~291) 之變化。 實驗結果顯示:外加水平上蓋平板可以有效地增強 空穴中剪力流之震盪特性,其中剪力流震盪特性之增強程度和平板前緣與空穴前緣之距離有 關。亦即向下游移動時,其間距離愈遠則其震盪特性被增強之程度愈小;反之,則愈強。然 而,當平板前緣位置向上游方向移動時,除了震盪振幅減弱之外,平板邊界層之發展對於空 穴中剪力流震盪特性產生破壞性之貢獻,最後將使流場演變成紊流狀態。外加水平上蓋平板 和空穴前緣相對位置之遠近直接影響到空穴與平板間之流場開始加速之位置;而對於其間加 速度大小之影響較小。另外,上蓋平板之高度則決定空穴與平板間流場之加速度大小,而對 於其間開始加速之位置則較無影響。 aining oscillation within the cavity. As the leading-edge of the top plate is located right above the most sensitive region (or the upstream corner) of the cavity shear layer, self-sustaining oscillation of the shear layer is significantly enhanced. The effectiveness reduces when the leading-edge of the top plate moves downstream away from the most sensitive region. While the leading-edge moves further upstream of the most sensitive region, the shear flow structure gradually becomes three-dimensional and turbulent leading to diminishing of the self-sustaining oscillation. However, the change of H/D provides only mild influence on the oscillating amplitude. The leading-edge location of the top plate primarily determines the onset location of flow acceleration, whereas the height of the top plate above the cavity determines the magnitude of the flow acceleration across the cavity mouth. The Reynolds number mainly determines the most unstable frequency of the cavity shear layer. |
本系統中英文摘要資訊取自各篇刊載內容。