Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1496
標題: 高速主軸迷宮式軸封之壓力與流場分析
Analysis of Flow Structure and Pressure Distrubutions within Labyrinth Seal for High Speed Spindle
作者: 林宜慶
lin, yi ching
關鍵字: Static pressure;靜壓力;flow structure;labyrinth seal;non-contact sealing;流場結構;迷宮式軸封;非接觸式軸封
出版社: 機械工程學系
摘要: 
本研究係以實驗方法量測迷宮式軸封流道壁面上之靜壓力分佈,配合數值分析軟體(Fluent),探討迷宮式軸封中不同軸向間隙比(G/S2)、軸向位移比(d/W)、徑向位移(S)以及徑向間隙(h)等參數變化時,軸封流道間之流場結構及靜壓力分佈的關係,研究結果顯示:
對A模型而言,軸向間隙比在2≦G/S2<3的範圍時,空穴B的渦旋結構強度較強,其留置外來異物之能力較佳。其中又以G/S2=2.5配合徑向間隙h=0.1mm,對外來氣體或異物之阻隔能力最好。當軸向間隙比在G/S2<2時,該模型阻隔外來流體的能力較差。再者,徑向間隙(h)逐漸增大,流道中阻力降低,對外來異物之阻隔效果有降低的趨勢。
對於B模型而言,徑向位移為S=15mm者,在空穴B中所產生的阻隔能力比S=25mm者較佳。其中當軸向位移d/W<0.2時,空穴B中壓力差(ΔPB)較小,阻隔效果較弱。當d/W≧0.2時,則壓力差(ΔPB)較大,阻隔效果較好。此外,當徑向間隙h>0.2mm,流體容易通過軸封流道之間隙,亦即對外來流體的阻隔能力較差。反之,徑向間隙h≦0.2mm時,流道阻力增加,其阻隔外物之能力較佳。其中徑向位移(S)、軸向位移(d)以及徑向間隙(h)等三個幾何參數之影響是緊密相關的,因此,以模型B之軸封設計,必須同時考慮此三個幾何參數之最佳化,方能提升軸封效率。

The purpose of this study is to investigate the static pressure distributions along the wall and flow structures within the labyrinth seal by experiments and numerical analysis. Two aims are expected: (1) To cross-link the flow structures in the flow path and the pressure distributions along the wall of labyrinth seal.(2) To understand the influences due to changes of geometric parameters, such as clearance (h), axial width (G and d), and radial displacement (S). Some important results are found and concluded as follows:
For A models:
(1)In the range of 2≦G/S2<3,vortex strength in cavity B is
strong enough to effectively trap the undesirable substances.
(2)Among A models, the conditions of G/S2=2.5 and h=0.1mm leads to the best sealing effectiveness. However for G/S2<2, the sealing effectiveness reduce significantly.
(3)Increasing the clearance (h) from 0.1mm to 0.5mm results in significant decrease in the flow path resistance, thus, the sealing effectiveness reduces.
For B models:
(1)The sealing effectiveness in cavity B of S=15mm is better than that of S=25mm.
(2)For d/W<0.2, the trapping ability in cavity B is weak. However, for d/W≧0.2, the trapping ability in cavity B largely increases due to different strength of vortex structure.
(3)Increasing the clearance (h) results in significant decrease in the flow path resistance, leading to poor sealing effectiveness.
It is advised that the sealing performance of both models A and B be greatly improved by optimizing these geometric parameters.
URI: http://hdl.handle.net/11455/1496
Appears in Collections:機械工程學系所

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