本研究在直徑0.38m之圓柱形攪拌槽中，透過粒子影像測速技術(Particle Image Velocimetry, PIV)觀察兩新型葉片在攪拌下產生的流動模式以及加裝PBCF (Propeller Boss Cap Fin)葉片後，觀察其對攪拌槽內之流動模式的影響。結果表明，推進式葉片之流動模式與軸流式葉片相近，而在加入PBCF葉片後葉輪下方區域之徑向方向速度增加，使流體得以流至壁面並在撞擊壁面後往攪拌槽中心流動在葉輪下方形成較小的環流，幫助底部流體更快到達液面。此外，最大剪切率在安裝PBCF葉片後提升19%。桶底葉片排出的流體主要沿著檔板向上排出，再受葉片旋轉吸引向下，形成環流，與推進式葉片組合後環流場高度從z/H=0~0.3變為z/H=0~0.8，顯著提升軸向循環能力，兩種Case之最大剪切率發生處皆在徑向速度最大的區域，而對於剪切率>1 s-1，安裝推進式葉片後比原先多出36%。還討論了根據混合時間及消耗功率定義的混合效率，其中加入PBCF葉片除了能增加混合效率以外所需消耗的功率也僅比無加裝PBCF葉片多出1~3%。

The particle image velocimetry technique was used to investigate the flow pattern generated by four cases of the impeller in a stirred tank. Case1 and Case3 were novel impellers designed by Metal Industries Research and Development Center. Case2 equipped the PBCF (Propeller Boss Cap Fin) on the impeller used in Case1, and Case4 was the impeller combination of Case1&3. Results showed that the flow pattern in Case1 was approximate to the axial impeller; the radial velocity component and shear rate under the impeller were increased and formed a circulation loop under the impeller after PBCF was mounted. The fluid discharged by Case3 mostly moved along the baffle and created a circulation loop in a stirred tank, the loop and the ability of axial recirculation enhanced after the combination in Case4. For both Case3 & 4, the maximum shear rate happened at the same location that had the highest radial velocity components, indicating that the radial velocity component dominated the shear rate in these two cases. The mixing efficiency rank of the four cases was as follows: Case2> Case1> Case4> Case3. Results showed that the mixing efficiency was higher after PBCF was equipped; however, the power consumption slightly increased.

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