本研究使用實驗方法對圓管噴流撞擊壁面並受到橫流影響時的流場特性進行研究。在一拖曳式水槽中安裝噴流與壁面設備，改變噴流出口與壁面間的距離對噴口直徑的比值(s/d = 5 - 25)與噴流對橫流速度比(Ru ≡ uj /u∞ = 3 - 58)，使用雷射光頁輔助質點軌跡流動可視化技術觀測橫流中衝擊噴流的行為；再以質點影像測速儀量測速度場，轉換成流線，進行流動拓樸分析，並計算渦度及紊流強度。受橫流影響下之衝擊噴流流場，在垂直對稱面呈現三種模態：無衝擊、輕微衝擊及衝擊效應主宰模態。在相同噴流對橫流速度比的條件下，隨著衝擊距離的增加，噴流對壁面的撞擊減弱。當衝擊距離固定時，若速度比增加，噴流對壁面的撞擊影響增強。在衝擊效應主宰模態中，橫流接近衝擊噴流所形成的界面與壁面交界的上游處會產生一至兩顆渦旋(較小的Ru產生一顆渦漩；較大的Ru產生兩顆渦漩)。水平面流場觀察與量測顯示，於無衝擊與輕微衝擊模態時，在噴流出口與壁面之間並無特殊流場結構；但於噴流圓管的下游有渦漩逸放產生。於衝擊效應主宰模態時，在距離壁面較近的水平面會產生馬蹄狀的渦旋；在距離壁面較遠的水平面則無馬蹄狀渦漩產生，於噴流圓管的下游亦有渦漩逸放產生。渦度與紊流強度分佈顯示，於衝擊效應主宰模態時，因橫流對衝擊噴流影響而產生的渦流附近會呈現較大的渦度與紊流強度。

The flow characteristics of an impinging jet in crossflow was studied experimentally in a towing water tank. The water jet flow was provided via a system composed of a pump, a small water tank, a rotameter, a needle valve, and a stainless-steel tube. The wall subject to the impingement of the water jet was an acrylic flat plate installed at a distance under the exit of the water jet. The tube and acrylic plate were linked together and immersed in the water of the towing water tank. The towing motion applied to the tube and flat plate induced the crossflow which would influence the flow field of the impinging jet. Two dominant physical and geometric nondimensional parameters were varied: (1) the jet-to-crossflow velocity ratio (Ru ≡ uj /uc = 3 - 58) and (2) the impingement distance to jet diameter ratio (s/d = 5 - 25). The laser-light sheet particle tracking flow visualization method and particle image velocimetry (PIV) were respectively used to probe the qualitative and quantitative flow characteristics. The velocity vectors, streamlines, topological patterns, vorticity distributions, and turbulence intensities were calculated and analyzed. Three characteristic flow modes: no impingement, slight impingement, and impingement effect dominated modes were observed in the domain of s/d and Ru in the vertical symmetry plane. No specific flow structures were found in the no impingement and slight impingement modes. In the impingement effect dominated mode, one or two vortices might appear in the vertical symmetry plane near the wall around the upstream area of the interface between the jet and the crossflow. These vortices were induced due to the interaction between the impingement of the jet on the wall and the crossflow at mid to high values of Ru. The primary flow feature appeared in the horizontal plane near the wall when the vortices presented was a horseshoe flow structure. The vorticities and turbulence intensities revealed notably high values around the area of the vortices.

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