• 沒有找到結果。

(1) 流場會因為攪拌葉片的傾角不同而改變,傾角越小,流場越接近軸向流場,

傾角越大越接近徑向流場。

(2) 逐漸改變攪拌葉片的傾角,發現到有一臨界角度,當角度在臨界角以下時,

流場屬於軸向流場,只要一超過此臨界角度時,流場就轉為徑向流場。

(3) 功率數與ε*在臨界角度以後有快速增加的情形,而κ*沒有此現象。

(4) 攪拌數在臨界角度以後會迅速降低,顯示在葉片旋轉區域範圍內的流體交換 速度降低。

(5) 每一個葉片間隙都有臨界角度,C=T/2 為 49 度,C=T/3 為 75 度,C=T/4 為 86 度,而且間隙越小,在臨界角以後轉為徑向流場的變化越明顯,間隙越大則 越不明顯。

(6) 葉片間隙越小,會使功率數與ε*會在臨界角度以後快速增加的幅度越大,葉 片間隙越大在臨界角度以後快速增加的幅度會越小,而間隙對κ*的曲線變化 影響不大。

(7) 葉片間隙越小,攪拌數就越大,間隙越大攪拌數則越小。

(8) 流場會因攪拌葉片間隙的不同而改變,在相同角度時攪拌葉片越接近槽底(間 隙越小),流場越接近軸向流場,攪拌葉片越離開槽底(間隙越大),流場越接 近徑向流場。

(9) 葉片直徑大小會改變臨界角度,使得本來 C=T/2 的臨界角度從 49 度(葉片直 徑 D=T/3),改變為 39 度(葉片直徑 D=T/2),兩個角度相差為 10 度範圍。C=T/3 的臨界角度從 75 度(葉片直徑 D=T/3),改變為 69 度(葉片直徑 D=T/2),兩個 角度相差為 6 度範圍。但是在間隙 C=T/4 時不管葉片直徑是 D=T/3 還是 D=T/2,臨界角度同樣為 86 度,可知當葉片直徑增加時,間隙越大臨界角度 改變越大,間隙越小臨界角度改變越小。

(10) 功率數與ε*會因葉片直徑增大而使得在臨界角度以後快速增加的幅度減

小,而葉片直徑對κ*的曲線變化影響不大。

(11) 攪拌數在葉片直徑加大後,在臨界角度以後快速減少的幅度變大。

(12) 轉速並不會影響流場型態,也不會影響功率數、ε*、κ*的大小,對攪拌數 的影響也不大。

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