臺灣博碩士論文加值系統

我們透過求解納維-斯托克斯方程和能量方程來對液壓軸承熱效應進行數值模擬分析。對液壓軸承來說，眾所皆知溫度影響潤滑油的粘度和軸承的負載能力。因此，本研究的主要目的是提出在不同潤滑油粘度及偏心比下，軸承的溫度與壓力分佈。在這項研究中，結果包括軸頸軸承索末菲數的驗證，以及人字形軸承、人字形軸承結合止推軸承與人字形軸承結合溝槽結構止推軸承的溫度與壓力分佈。結果顯示當潤滑油薄膜溫度升高，其軸承負載能力下降。偏心比增加，軸向速度和壓力差變大。人字形軸承有效地將高壓分散於溝槽尖端，增加穩定性。此外，結合人字形軸承與溝槽結構止推軸承，運作時也會產生額外作用力穩定軸的運轉。這些發現將有助於了解液壓軸承的最佳工作環境以便未來軸承設計。

We numerically analyzed a hydrodynamic bearing with thermal effects by solving Navier-Stokes and energy equations. For a hydrodynamic bearing (HDB), it is well known that high temperature affects the lubricant viscosity and the bearing load capacity. Therefore, the main objective of this study is to present temperature and pressure distribution of a hydrodynamic bearing under different values of lubricant viscosity and eccentricity ratio. In this study, the results include the verification of Sommerfeld number for a journal bearing, pressure and temperature distribution for herringbone-grooved journal bearing (HGJB), HGJB with thrust bearing, and HGJB with grooved thrust bearing. The bearing characteristics such as load capacity and eccentricity ratio are also discussed. Results show that the load capacity of the bearing decreases as temperature increase. Also the axial velocity and pressure difference rise as the eccentricity ratio increase. HGJB concentrates the pressure distribution on the groove tip. Also, the HGJB with grooved thrust bearing can be used to stabilize the journal. These findings may help and facilitate the bearing design for a suitable operating environment in the future.

摘 要 ................................................................................................. ii
ABSTRACT ................................................................................................. iii
Ackonwledgements ...................................................................................... iv
Contents ......................................................................................................... v
List of Tables ................................................................................................ vi
List of Figures ............................................................................................. vii
Nomenclatures .............................................................................................. xi
1. Introduction ............................................................................................ 1
2. Numerical Model ................................................................................... 5
2.1 Problem Descriptions ...................................................................... 5
2.2 Governing Equations ....................................................................... 6
2.3 Boundary Conditions ...................................................................... 7
2.3.1 Case 1: Journal bearing ........................................................ 7
2.3.2 Case 2: HGJB ....................................................................... 8
2.3.3 Case 3: HGJB with thrust bearing ....................................... 8
2. 3.4 Case 4: HGJB with grooved thrust bearing ........................ 9
2.4 Grid Independence .......................................................................... 9
3. Results and Discussion ......................................................................... 11
3.1 Case 1: Journal bearing ................................................................. 11
3.2 Case 2: HGJB ................................................................................ 13
3.3 Case 3: HGJB with thrust bearing ................................................ 14
3.4 Case 4: HGJB with grooved thrust bearing .................................. 15
4. Conclusions and Future Work .............................................................. 17
4.1 Conclusions ................................................................................... 17
4.2 Future work ................................................................................... 18
References ................................................................................................... 19

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