Effects of lubricant fluid with nanoparticle additive on the load capacity of a hydrostatic journal bearing

Yıl 2020, , 753 - 762, 31.05.2020

Abdurrahim Dal Mustafa Kılıç , Ali Özhan Akyüz , Azim Doğuş Tuncer , Afşin Güngör

https://doi.org/10.31202/ecjse.686845

Öz

Hydrostatic journal bearings are recommended for supporting shafts operating at high speeds and under heavy loads in the industry. In the journal bearings, lubricant viscosity decreases with increasing temperature at high rotation speeds and hence, the fluid between the surfaces should be circulated by means of a pump in order to cool the lubricant. However, lubricant supplying between the surfaces at the high flow rate causes the whirl instability and vibrations problems in the bearing-shaft system. These instability problems give rise to significant damage on the system during operating at the high speeds and under the heavy loads. As a solution of this problem, it could be suggested to control the variation of the lubricant viscosity with respect to the temperature by adding nanoparticle. In the present work, the effects of the lubricant with nanoparticle additives on the load performance of a hydrostatic journal bearing are theoretically investigated. The fluid film flow between the bearing and rotor surfaces are modelled with Reynolds equation and viscosity term in Reynold’s equation is defined as a function which is depends on the nanoparticle properties. Then, the pressure distribution of the bearing is obtained with numerically solving the Reynolds equation and the load capacity is calculated for different nanoparticle parameters with using this pressure distribution. The results show that the usage of the lubricant with nanoparticle increase the load performance of the hydrostatic journal bearing.

Anahtar Kelimeler

Rotordynamics, load capacity, lubricant with nanoparticle, hydrostatic journal bearing

Nanoparçacık katkılı yağlayıcı akışkanın radyal hidrostatik yatağın yük taşıma kapasitesine etkisi

Öz

Hidrostatik yataklar, endüstride, yüksek hızlarda ve ağır yükler altında çalışan şaftların yataklanması için önerilmektedir. Bu yataklarda, sıcaklığın artması akışkanın viskozitesini düşürmektedir ancak, akışkanın soğutulması için yüzeyler arasındaki akışkan, bir pompa ile devridaim ettirilebilir. Fakat yatak-şaft sistemlerinde, yüzeyler arasına akışkan iletilmesi, dolanım kararsızlıklarına ve titreşim problemlerine sebep olduğu bilinmektedir. Bu kararsızlık problemleri şaftın yüksek hızlarda dönüşü esnasında sisteme önemli hasarlar verebilecek kadar tehlikeli olabilir. Bu probleme çözüm önerisi olarak, yağlayıcı akışkanın viskozitesinin sıcaklığa bağlı değişiminin nanoparçacıklarla kontrol edilmes önerilebilir. Bu çalışmada da, hidrostatik yataklarda nanoparçacık ilaveli yağlayıcı akışkan kullanımının yük taşıma kapasitesine etkisi teorik olarak araştırılmıştır. Yüzeyler arasındaki akışkan hareketi Reynolds denklemi ile modellenmiş ve denklem içerisindeki viskozite terimi nanoparçacık özelliklerine bağlı olarak ifade edilmiştir. Bunun ardından, yatak içerisindeki basınç dağılımı Reynolds denkleminin sayısal çözümü ile elde edilmiş ve bu basınç dağılımı kullanılarak, yatağın yük taşıma kapasitesi, farklı nanoparçacık özellikleri için hesaplanmıştır. Yapılan bu çalışmanın sonuçları, nanoparçacık takviyeli yağlayıcı kullanımının hidrostatik yatakların yük taşıma kapasitesini arttırdığını göstermiştir.

Anahtar Kelimeler

Rotor dinamiği, yük kapasitesi, nanaoparçacık takviyeli yağlayıcı, radyal hidrostatik yatak

Kaynakça

• [1] Rowe WB (1983) Hydrostatic and Hybrid Bearing Design. London: Butterworths
• [2] Rowe WB, Chong FS, Weston W (1984). A linearised stability analysis of rigid and flexible rotors in plain hybrid (hydrostatic/hydrodynamic) journal bearings, In: Proc. Conf. on Vibrations in Rotating Machinery, York
• [3] Tonnesen J, Hansen PK (1981) Some Experiments on the Steady-State Characteristics of a Cylindrical Fluid-Film Bearing Considering Thermal Effects, Asme Journal of Lubrıcation Technology 103:107-114
• [4] Loxham J, Hemp J (1964) The application of hydrostatic bearings to high precision machine tools. Prod Eng 43:556-568
• [5] Rowe WB, Koshal D, Stout KJ (1977) Investigation of recessed hydrostatic and slot entry journal bearings for hybrid hydrodynamic and hydrostatic operation. Wear 43: 55-69
• [6] Cossa KN (2019) Basic concepts on rheology and application of shear-thickening fluids in protective gear. SN Appl. Sci. 1:1284
• [7] Ghosh MK, Majumdar BC (1980) Design of multirecess hydrostatic oil journal bearings. Tribology International 13:73–78
• [8] Yoshimoto S, Rowe WB, Ives D (1988) A theoretical investigation of the effect of inlet pocket size on the performance of hole entry hybrid journal bearings employing capillary restrictors. Wear 127:307-318
• [9] Rana NK, Gautam SS, Verma S (2019) Stifness and damping characteristics of conical multirecess hybrid journal bearing for diferent load arrangements. SN Applied Sciences 1:604
• [10] Dwivedia VK, Chandb S, Pandey KN (2013) Effect of number and size of recess on the performance of hybrid (hydrostatic/hydrodynamic) journal bearing. Proced Eng 51:810–817
• [11] Kumar V, Sharma SC, Jain SC (2005) Journal Motion of Hybrid Journal Bearing Considering Viscosity Variation due to Temperature Change. In: ASME International Mechanical Engineering Congress and Exposition, Orlando, Florida, USA
• [12] Phalle VM, Sharma SC, Jain SC (2012) Performance analysis of a 2-lobe worn multirecess hybrid journal bearing system using different flow control devices. Tribol Int 52:101-116
• [13] Peng L, Changhou L, Wei P, Shiyi L (2014) A new method for calculating the static performance of hydrostatic journal bearing. Tribology International 77: 72-77
• [14] Khatak, P and Garg, H (2012) Influence of micropolar lubricant on bearings performance: A review. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 226(9):775-784
• [15] Rajneesh K, Suresh V (2016) Analysis of Noncircular Hole-Entry Capillary-Compensated Hybrid Journal Bearing with Micropolar Lubrication. Tribology Transactions 59:33-43
• [16] Chandra BK, Sharma SC (2016) Influence of textured surface on the performance of non-recessed hybrid journal bearing operating with non-Newtonian lubricant. Tribology International 95:221-235
• [17] S, Kumar V, Gupta KD (2009) Analysis of Multirecess Hydrostatic Journal Bearing Operating With Micropolar Lubricant. ASME. J. Tribol. 131(2):021103
• [18] Shenoy BS, Binu KG, Pai R, Rao DS, Pai RS (2012) Effect of nanoparticles additives on the performance of an externally adjustable fluid film bearing. Tribology International 45: 38-42.
• [19] Peng XD, Chen CH, Kang Y, Chang YP, Chang SY (2010) Size Effects of SiO2 Nanoparticles as Oil Additives on Tribology of Lubricant. Industrial Lubrication and Tribology 62: 111-120
• [20] Jiao D, Zheng S, Wang Y, Guan R, Cao B (2011) The Tribology Properties of Alumina/Silica Composite Nanoparticles as Lubricant Additives. Applied Surface Science 257(13):5720–5725
• [21] Padgurskas J, Rukuiza R, Prosyčevas I, Kreivaitis R (2013) Tribological Properties of Lubricant Additives of Fe, Cu and Co Nanoparticles. Tribology International 60:224–232
• [22] Nair KP, Ahmed MS, Qahtani STA (2009) Static and Dynamic Analysis of Hydrodynamic Journal Bearing Operating Under Nano Lubricants. International Journal of Nanoparticles 2:251-262
• [23] Nicoletti R (2014) The Importance of the Heat Capacity of Lubricants with Nanoparticles in the Static Behavior of Journal Bearings. Journal of Tribology 136:044502.
• [24] Binua KG, Shenoyb BS, Raoa DS, Paia R (2014) Static Characteristics of A Fluid film Bearing with TiO2 Based Nanolubricant Using the Modified Krieger–Dougherty Viscosity Model and Couple Stress Model, Tribology International 75:69-79.
• [25] Yathish K, Binu K (2017) Static Characteristics of Two-Axial Groove Journal Bearing Operating on TiO2 Nanolubricant Using A Temperature Dependent Viscosity Model. Journal of Mechanical Engineering and Automation 7:150-154.
• [26] Babu KS, Nair KP, Rajendrakumar PK (2014) Computational Analysis of Journal Bearing Operating Under Lubricant Containing Al2O3 and ZnO Nanoparticles. International Journal of Engineering, Science and Technology 6:34-42
• [27] Dal A (2017). Dynamics analysis of a shaft supported by radial aerostatic bearings using hybrid solution approach and its experimental investigation, Ph.D., Gazi University, Ankara, Turkey