本研究藉由數值模擬方法研究兩道相鄰、平行且等速的二維噴流在不同間隔時的流動型態與流場特性。二維噴流出口之寬度d = 4 mm，改變兩道噴流出口中心之間的距離s，使其與噴流出口寬度d 的比值為s/d =5、10、15，分析噴流出口低雷諾數Rej =200~1600 的雙平面平行噴流特徵。模擬結果發現兩噴流之間迴流區的鞍點，其形狀與結構不受噴流出口間隔距離及雷諾數Rej 變化的影響，而大小與噴流出口間隔距離成正比。噴流於進入匯合區迅速後內縮，同時速度下降，當兩噴流不再內縮而平行前進時，速度開始上升。合併點隨噴流出口間隔距離增加而位置往下游移動，但不受雷諾數影響；結合點則隨噴流出口間隔距離及雷諾數增加而位置往下游移動。相同噴流間隔距離下，隨著雷諾數增高，結合點高度位置越高。中心軸噴流通過結合點後形成結合噴流時，流速與噴流出口速度比值（ujc/uec）於較低雷諾數(200~1200)時大致一致，對於高雷諾數(1400~1600)時比值則明顯較低雷諾數(Rej =200~1200)為高。噴流於匯合區時，兩噴流峰值中間渦度趨近於零；相同噴流出口間隔距離下，高雷諾數(1400~1600)整體渦度變化較低雷諾數(200~1200)為高。

In this study, the flow pattern and flow field characteristics of two-dimensional jet issuing from two adjacent, parallel with constant velocity at different intervals are analyzed by 2D-CFD. The widths of the jet exits were 4 mm. The ratios of the spacing between the two jets to the width of the jet exits were 5, 10, and 15. The Reynold number range were between 200 and 1600. The CFD results show that there is a saddle point in the recirculation zone between the two jets. The saddle points have similar-shaped structures but are not affected by the different Reynold number and the ratios of the spacing between the two jets to the width of the jet exits. The jets approach each other in the converging region, and velocity is rise. When the two jets are no longer approached each other and advance in parallel, the velocity are decreased. The merge point moves downstream as the nozzle exit spacing increases, but is not affected by the Reynolds number. The combined point moves downstream as the nozzle exit spacing increases or the Reynolds number increases. The ratios of the combined jet velocity and the outlet velocity are the same between Reynolds number 200 and 1200, but are different between Reynolds number 1400 and 1600. In converging region, the vorticity between two jet approaches zero. At the same two jets to the width of the jet exits, the overall vorticity change of Reynolds number between 1400 and 1600 is higher than the Reynolds number of 200 to 1200.

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