Responsive image
博碩士論文 etd-0808116-095932 詳細資訊
Title page for etd-0808116-095932
論文名稱
Title
兩接觸表面之吸附油膜對乳化液潤滑特性的影響
Effects of Adsorbed Films on Two Contact Surfaces on Lubricating Characteristics of Emulsions
系所名稱
Department
畢業學年期
Year, semester
語文別
Language
學位類別
Degree
頁數
Number of pages
126
研究生
Author
指導教授
Advisor
召集委員
Convenor
口試委員
Advisory Committee
口試日期
Date of Exam
2016-07-26
繳交日期
Date of Submission
2016-09-08
關鍵字
Keywords
彈塑液動潤滑、吸附油層、熱彈液動潤滑、滾滑比、冷軋加工、乳化液
slide/roll ratio, TEHL, adsorbed layer, EPHL, emulsion, cold rolling
統計
Statistics
本論文已被瀏覽 5728 次,被下載 1
The thesis/dissertation has been browsed 5728 times, has been downloaded 1 times.
中文摘要
本研究提出一含兩吸附油層之乳化液的混合油膜模型,推導及求解兩相混合物之修正雷諾氏方程式與能量方程式。使用此模型進行一系列模擬分析,在等溫彈液動潤滑方面,首先確認兩吸附油層合併與否之「臨界速度」,亦即在轉速大於此臨界速度時,兩吸附油層會被乳化液層分開,中央油膜厚度會隨著轉速與供給之油相濃度增加而變厚,這是因為更多的乳化液會被夾帶進入赫茲接觸區。當轉速小於此臨界速度時,則兩吸附油層之總厚度會大於中央油膜厚度然後合併進而形成連續油相,若轉速繼續降低,此連續油相之位置將會往上游移動並且形成油池。最後與實驗互相比較,成功估算奈米級的進口吸附油層厚度,然而其厚度會隨著轉速降低而變厚,這是因為有足夠時間讓油滴吸附於滾子軸承表面。
在熱彈液動潤滑方面,結果顯示由於乳化液層是最主要熱量的來源,因此最大溫昇發生在乳化液層,速度較快的上吸附油層與乳化液層之界面吸收熱量之時間較下界面短,所以其溫昇小於下界面之溫昇。在平均轉速小於3 m/s之條件下,熱彈液動與等溫彈液動之最小油膜厚度非常的接近,但隨著平均轉速增加,熱彈液動之溫昇漸漸變大而使得乳化液層之黏度慢慢下降,因此熱彈液動與等溫彈液動之最小油膜厚度則愈差愈大,此結果之趨勢與純油相同。吸附油層之油膜方向溫度會由界面至固體表面漸漸遞減,因此較薄之吸附油層會有較短之距離降溫,所以較薄吸附油層之固體表面溫度會大於較厚吸附油層之值。與純滾動比較,低油相濃度在高滾滑比時的最小油膜厚度比高油相濃度減少較少,除了其溫昇較小之外,最主要原因是乳化液層中之水相含量太多而使得黏度僅微小下降。與最大赫茲壓力0.284 GPa比較,低油相濃度在1.421 GPa條件下的最小油膜厚度比高油相濃度減少較少,其主要原因也是乳化液層中之水相含量太多所造成。
在冷軋加工之彈塑液動潤滑方面,結果顯示在低輥輪速度或吸附層合併之條件下,存在一個不需施加前向張力就能提供充足摩擦力之範圍。當輥輪速度較高時,兩吸附油層會被乳化液層分開,壓力丘會因為作用於薄板之剪應力變小而消失,使得輥軋將無法繼續進行,除非有施加前向張力。較大的前向張力會伴隨著較快的薄板進口速度以及較大的油膜厚度。兩吸附油層被乳化液層分開之情形下,吸附油層之速度輪廓幾乎維持常數,雖然乳化液層有較大的剪應變率,但作用於薄板之剪應力僅受吸附油層影響,所以此情形之薄板剪應力非常的小。進口油膜厚度會隨著降低等效彈性模數或增加前向張力而變厚。
Abstract
A mixed-film model with two adsorbed layers on the solid surfaces and an emulsion layer between them is proposed. The modified Reynolds and energy equations of binary mixtures are derived and solved for this model. A series of simulations using this model are carried out. For the isothermal EHL (elastohydrodynamic lubrication), “the critical speed” is firstly identified, based on which the adsorbed layers can be merged or separated. The two adsorbed layers are separated by the emulsion when the rolling speed is greater than the critical speed, and the central film thickness increases along with the rolling speed and supply oil concentration, because more emulsion is entrained into the Hertzian contact zone. When the rolling speed is less than the critical speed, the total thickness of the two adsorbed layers is greater than the central film thickness, and thus they merge to form the continuous oil phase. If the rolling speed continues to slow down, the position of the continuous oil phase moves upstream, and finally an oil pool is formed. Compared with the experimental results, the nano thickness of the adsorbed layer at the entrance can be successfully predicted. However, the adsorbed layer thickness increases with decreasing rolling speed, because there is enough time to replenish the adsorbed film.
For the TEHL (thermal elastohydrodynamic lubrication), the maximum temperature rise occurs at the emulsion layer because the emulsion layer is the main source of heat. The heat source transfers into the upper interface between the adsorbed and emulsion layers with higher speed in a shorter time, so that its temperature rise is less than the lower one. The minimum film thickness for the thermal case is close to the isothermal solution at the average rolling speed less than 3 m/s, but the difference between them increases along with the rolling speed because the viscosity of the emulsion layer decreases with increasing mean temperature rise. This trend is the same as the result of pure oil in thermal EHL. The temperature rise across the adsorbed layer gradually decreases from the interface to the surface. The surface temperature rise increases with decreasing adsorbed layer thickness due to the shorter distance for the conduction heat transfer. Compared with the results of the pure rolling, the decrement of the minimum film thickness for the lower supply oil concentration at high slide/roll ratio is less than that for the higher one, because the viscosity of the emulsion layer with more amount of water phase is decreased slightly besides the lower temperature rise. Compared with the results of the maximum Hertzian pressure ph = 0.284 GPa, the decrement of the minimum film thickness for the lower supply oil concentration at ph = 1.421 GPa is less than that for the higher one due to the same reason.
For the EPHL (elasto-plasto-hydrodynamic lubrication) of cold rolling, there existed a range of roll speeds which provided sufficient friction to perform the rolling process without front tension under the merged conditions and the lower roll speeds. At the high roll speed, the two adsorbed layers were separated by the emulsion layer, and the pressure hill disappeared due to the smaller surface shear stress acting on the strip, so that the rolling was no longer possible unless accompanied by a front tension. The greater the front tension, the greater the velocity of the strip in the work zone, and the thicker the emulsion layer. For the separated case, the velocity of the adsorbed layers along the z axis almost remained constant, and the shear strain rate due to the surface velocity difference between the roll and the strip mainly occurred at the emulsion layer. However, the surface shear stress acting on the strip was affected by the adsorbed layer, so that it was very small. The inlet film thickness increased with decreasing effective modulus of elasticity or increasing front tension.
目次 Table of Contents
論文審定書................................................................i
誌 謝......................................................................ii
摘 要......................................................................iii
Abstract...................................................................v
目 錄......................................................................vii
圖 次......................................................................x
表 次......................................................................xiv
符號說明...................................................................xv
第一章 總論...............................................................1
1.1 研究動機與背景....................................................1
1.2 文獻回顧..............................................................2
1.2.1 乳化液潤滑之實驗研究........................................2
1.2.2 乳化液潤滑之理論分析........................................8
1.2.3 冷軋加工之相關研究...........................................13
1.2.4 吸附油層之相關研究...........................................15
1.2.5 熱彈液動潤滑之理論分析.....................................18
1.3 本論文之研究目的.................................................21
1.4 本論文架構...........................................................23
第二章 理論模型.........................................................25
2.1 雷諾氏方程式........................................................26
2.2 能量方程式...........................................................32
2.3 表面與界面之溫度.................................................39
第三章 乳化液在等溫彈液動潤滑接觸區之研究...............40
3.1 純滾動條件下之統御方程式....................................40
3.2 牛頓-瑞福遜法.......................................................43
3.3 結果與討論...........................................................44
3.3.1 油相濃度對油膜厚度之影響.................................45
3.3.2 吸附油層厚度對油膜厚度之影響...........................46
3.3.3 數值模擬與實驗數據比較之結果...........................50
3.4 結論.....................................................................53
第四章 乳化液在熱彈液動潤滑接觸區之研究..................54
4.1 黏度與密度公式....................................................54
4.2 結果與討論...........................................................55
4.2.1 油相濃度之影響.................................................55
4.2.2 吸附油層厚度之影響...........................................62
4.2.3 滾滑比與負荷之影響...........................................65
4.3 結論....................................................................71
第五章 乳化液的混合油膜模型應用於冷軋潤滑之研究....72
5.1 冷軋潤滑之理論分析.............................................72
5.1.1 進口區..............................................................76
5.1.2 加工區..............................................................76
5.1.3 出口區..............................................................77
5.2 結果與討論..........................................................79
5.2.1 數值模擬與實驗數據相互驗證之結果....................81
5.2.2 不考慮前、後向張力之兩吸附油層合併之結果.......84
5.2.3 輥輪速度與張力對油膜厚度之影響.......................90
5.3 結論....................................................................93
第六章......................................................................94
6.1 總結....................................................................94
6.2 未來展望.............................................................96
參考文獻...................................................................97
參考文獻 References
[1] Dowson, D. and Higginson, G.R., Elastohydrodynamic Lubrication. 1966, London: Pergamon P.
[2] Mang, T. and Dresel, W., Lubricants and Lubrication. 2001, Wiley.
[3] Wan, G.T.Y., Kenny, P. and Spikes, H.A., Elastohydrodynamic properties of water based fire-resistant hydraulic fluids. Tribology International 17 (1984) 309-315.
[4] Kimura, Y. and Okada, K., Lubricating properties of oil in water emulsions. Tribology Transactions 32 (1989) 524-532.
[5] Barker, D.C., Johnston, G.J., Spikes, H.A. and Bunemann, T., EHD film formation and starvation of oil in water emulsions. Tribology Transactions 36 (1993) 565-572.
[6] Zhu, D., Bireshaw, G., Clark, S.J. and Kasun, T.J., Elastohydrodynamic lubrication with O/W emulsions. Transactions of ASME, Journal of Tribology 116 (1994) 310-320.
[7] Ratoi-Salagean, M., Spikes, H. and Hoogendoorn, R., The design of lubricious oil-in-water emulsions. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 211 (1997) 195-208.
[8] Reich, R. and Urbanski, J., Experimental support for the dynamic concentration theory of forming an oil reservoir at the inlet of the roll bite by measuring the onset speed of starvation as a function of oil concentration and droplet size. Tribology Transactions 47 (2004) 489-499.
[9] Yang, H., Schmid, S.R., Reich, R.A. and Kasun, T.J., Direct observations of emulsion flow in elastohydrodynamically lubricated contacts. Transactions of ASME, Journal of Tribology 128 (2006) 619-623.
[10] Cambiella, A., Benito, J.M., Pazos, C., Coca, J., Ratoi, M. and Spikes, H.A., The effect of emulsifier concentration on the lubricating properties of oil-in-water emulsions. Tribology Letters 22 (2006) 53-65.
[11] Wilson, W.R.D., Sakaguchi, Y. and Schmid, S.R., A dynamic concentration model for lubrication with oil-in-water emulsions. Wear 161 (1993) 207-212.
[12] Wilson, W.R.D., Sakaguchi, Y. and Schmid, S.R., A mixed flow model for lubrication with emulsions. Tribology Transactions 37 (1994) 543-551.
[13] Schmid, S.R. and Wilson, W.R.D., Lubrication mechanisms for oil-in-water emulsions. Society of Tribologists and Lubrication Engineers 52 (1995) 168-175.
[14] Dow, T.A., A rheology model for oil-in-water. CASA-SME Technical Paper (1977) 77-339.
[15] Al-Sharif, A., Chamniprasart, K., Rajagopal, K.R. and Szeri, A.Z., Lubrication with binary mixtures: liquid-liquid emulsion. Transactions of ASME, Journal of Tribology 115 (1993) 46-55.
[16] Wang, S.H., Al-Sharif, A., Rajagopal, K.R. and Szeri, A.Z., Lubrication with binary mixtures: liquid-liquid emulsion in an EHL conjunction. Transactions of ASME, Journal of Tribology 115 (1993) 515-522.
[17] Dai, F. and Khonsari, M.M., A Theory of Hydrodynamic Lubrication Involving the Mixture of Two Fluids. Transactions of ASME, Journal of Applied Mechanics 61 (1994) 634-641.
[18] Yan, S. and Kuroda, S., Lubrication with emulsion: first report, the extended Reynolds equation. Wear 206 (1997) 230-237.
[19] Yan, S. and Kuroda, S., Lubrication with emulsion II. The viscosity coefficients of emulsions. Wear 206 (1997) 238-243.
[20] Benner, J.J., Sadeghi, F., Hoeprich, M.R. and Frank, M.C., Lubricating Properties of Water in Oil Emulsions. Transactions of ASME, Journal of Tribology 128 (2005) 296-311.
[21] Lo, S.W., Huang, K.C. and Zhou, M.C., CFD study on oil-in-water emulsions. Tribology Transactions 52 (2009) 66-72.
[22] Lo, S.W., Yang, T.C., Cian, Y.A. and Huang, K.C., A model for lubrication by oil-in-water emulsions. Transactions of ASME, Journal of Tribology 132 (2010) 011801-1-011801-9.
[23] Wang, S.H., Szeri, A.Z. and Rajagopal, K.R., Lubrication with emulsions in cold rolling. Transactions of ASME, Journal of Tribology 115 (1993) 523-531.
[24] Szeri, A.Z. and Wang, S.H., An elasto-plasto-hydrodynamic model of strip rolling with oil/water emulsion lubricant. Tribology International 37 (2004) 169-176.
[25] Kosasih, P.B. and Tien, A.K., Mixed film lubrication of strip rolling using O/W emulsions. Tribology International 40 (2007) 709-716.
[26] Lugt, P.M., Wemekamp, A.W. and tenNapel, W.E., Lubrication in cold rolling: elasto-plasto-hydrodynamic lubrication of smooth surfaces. Wear 166 (1993) 203-214.
[27] Cheng, H.S., Plastohydrodynamic lubrication. In: Friction in metal processing, in Friction and Lubrication in Metal Processing, ASME. 1966: New York. p. 69-89.
[28] Atkins, A.G., Hydrodynamic lubrication in cold rolling. International Journal of Mechanical Sciences 16 (1974) 1-19.
[29] Lin, J.F. and Jone, R.C., Analysis of thermal hydrodynamic lubrication in high-speed rolling. Part I: the effect of the roller’s elastic deformation. Tribology International 25 (1992) 329-339.
[30] Lin, J.F. and Horng, J.H., Analysis of thermal hydrodynamic lubrication in high-speed rolling. Part II: the effect of non-Newtonian viscosity models. Tribology International 25 (1992) 341-349.
[31] Wilson, W.R.D. and Walowit, J.A., An isothermal hydrodynamic lubrication theory for strip rolling with front and back tension. IMechnE C86/71 (1971) 164-172.
[32] Schey, J.A., Tribology in Metalworking: Friction, Lubrication and Wear. 1984, Metals Park, Ohio: American Society for Metals. p. 153.
[33] Fujita, N. and Kimura, Y., Influence of plate-out oil film on lubrication characteristics in cold rolling. ISIJ International 52 (2012) 850-857.
[34] Fujita, N. and Kimura, Y., Plate-out efficiency related to oil-in-water emulsions supply conditions on cold rolling strip. Proceedings IMechE Part J: Journal of Engineering Tribology 227 (2012) 413-422.
[35] Azushima, A. and Inagaki, S., Measurement and analysis of inlet oil film thickness in cold sheet rolling with oil-in-water emulsion. Tribology Transactions 52 (2009) 427-434.
[36] Azushima, A., Ohta, H. and Inagaki, S., Evaluation of occurrence of surface brightness irregularity in cold rolling of stainless steel with emulsion. Tribology Transactions 54 (2011) 685-690.
[37] Azushima, A., Inagaki, S. and Ohta, H., Plating out oil film thickness on roll and workpiece during cold rolling with O/W emulsion. Tribology Transactions 54 (2011) 275-281.
[38] Tieu, A.K., Kosasih, P.B. and Godbole, A., A thermal analysis of strip-rolling in mixed-film lubrication with O/W emulsions. Tribology International 39 (2006) 1591-1600.
[39] Tseng, A.A., Thermal characteristics of roll and strip interface in modeling rolling processes. Journal of Materials Processing and Manufacturing Science 6 (1997) 3-17.
[40] Cheng, H.S., A refined solution to the thermal elastohydrodynamic lubrication of rolling sliding cylinders. ASLE Transactions 8 (1965) 397-410.
[41] Cheng, H.S. and Sternlicht, N., A numerical solution for the pressure, temperature and film thickness between two infinitely long, lubricated rolling and sliding cylinders, under heavy loads. Transactions of ASME, Journal of Fluids Engineering 87 (1965) 695-707.
[42] Ghosh, M.K. and Hamrock, B.J., Thermal elastohydrodynamic lubrication of line contacts. ASLE Transactions 28 (1985) 159-171.
[43] Hsiao, H.S. and Hamrock, B.J., A complete solution for thermal-elastohydrodynamic lubrication of line contacts using circular non-Newtonian fluid model. Transactions of ASME, Journal of Tribology 114 (1992) 540-552.
[44] Lee, R.T. and Hsu, C.H., A fast method for the analysis of thermal-elastohydrodynamic lubrication of rolling/sliding line contacts. Wear 166 (1993) 107-117.
[45] Lee, R.T. and Hsu, C.H., Advanced multilevel solution for thermal-elastohydrodynamic lubrication of simple sliding line contacts. Wear 171 (1994) 227-237.
[46] Lee, R.T. and Hsu, C.H., An efficient algorithm for thermal elastohydrodynamic lubrication under rolling/sliding line contacts. Transactions of ASME, Journal of Tribology 116 (1994) 762-769.
[47] Lee, R.T., Hsu, C.H. and Kuo, W.F., Multilevel solution for thermal elastohydrodynamic lubrication of rolling/sliding circular contacts. Tribology International 28 (1995) 541-552.
[48] Sadeghi, F. and Sui, P.C., Thermal elastohydrodynamic lubrication of rolling/sliding contacts. Transactions of ASME, Journal of Tribology 112 (1990) 189-195.
[49] Salehizadeh, H. and Saka, N., Thermal non-Newtonian elastohydrodynamic lubrication of rolling line contacts. Transactions of ASME, Journal of Tribology 113 (1991) 481-491.
[50] Wang, S., Conry, T.F. and Cusano, C., Thermal non-Newtonian elastohydrodynamic lubrication of line contacts under simple sliding conditions. Transactions of ASME, Journal of Tribology 114 (1992) 317-327.
[51] Chu, L.M., Lee, R.T. and Chiou, Y.C., Inverse approach for estimating rheological characteristics of adsorption layer in thin film EHL contacts. Tribology International 39 (2006) 50-59.
[52] Carslaw, H.S. and Jaeger, J.C., Conduction of Heat in Solid. 1959, Oxford: Oxford University Press.
[53] Roelands, C.J.A., Correlational aspects of the viscosity-temperature-pressure relationship of lubricating oils. 1966, Groningen, the Netherlands: Druk VRB.
[54] Dalmaz, G. and Godet, M., Film thickness and effective viscosity of some fire resistant fluids in sliding point contact. Transactions of ASME, Journal of Lubrication Technology 100 (1978) 304-308.
[55] Pan, P. and Hamrock, B.J., Simple formulas for performance parameters used in elastohydrodynamically lubricated line contact. Transactions of ASME, Journal of Tribology 111 (1989) 246-251.
[56] Barus, C., Isothermals, isopiestics and isometrics relative to viscosity. American Journal of Science 45 (1893) 87-96.
[57] VonKármán, T., Beitrag zur Theorie des Walzvorganges. Vortäge der Dresdener Tagung 5 (1925) 139-141.
電子全文 Fulltext
本電子全文僅授權使用者為學術研究之目的,進行個人非營利性質之檢索、閱讀、列印。請遵守中華民國著作權法之相關規定,切勿任意重製、散佈、改作、轉貼、播送,以免觸法。
論文使用權限 Thesis access permission:自定論文開放時間 user define
開放時間 Available:
校內 Campus: 已公開 available
校外 Off-campus:永不公開 not available

您的 IP(校外) 位址是 44.200.196.38
論文開放下載的時間是 校外不公開

Your IP address is 44.200.196.38
This thesis will be available to you on Indicate off-campus access is not available.

紙本論文 Printed copies
紙本論文的公開資訊在102學年度以後相對較為完整。如果需要查詢101學年度以前的紙本論文公開資訊,請聯繫圖資處紙本論文服務櫃台。如有不便之處敬請見諒。
開放時間 available 永不公開 not available

QR Code