Sreedhar Babu Kalakada, Prabhakaran Nair Nair Kumarapillai and Rajendra Kumar P K
The purpose of this work is to investigate the static performance characteristics of thermohydrodynamic journal bearing operating under nanolubricants (lubricants containing per…
Abstract
Purpose
The purpose of this work is to investigate the static performance characteristics of thermohydrodynamic journal bearing operating under nanolubricants (lubricants containing per cent weight concentration of nanoparticles).
Design/methodology/approach
Addition of nanoparticles in the lubricant increases lubricant viscosity. To study the effect of this variation on journal bearing, analytical models are developed for the relationship between viscosity, 0-0.5 per cent weight concentration of nanoparticles and temperature range of 300-900°C. To obtain pressure and temperature distribution, modified Reynolds and energy equations are solved by using the finite element method. The viscosity field (varies with temperature and per cent weight concentration of nanoparticles) is updated in these two equations by using the developed analytical model. The steady-state performance characteristics are computed for various values of eccentricity ratios for non-thermoviscous (viscosity of lubricant varies with per cent weight concentration of nanoparticles) and thermoviscous (viscosity of lubricant varies with per cent weight concentration of nanoparticles and temperature) cases. The lubricant and the nanoparticles used for the present work are SAE15W40, copper oxide (CuO), cerium oxide (CeO2) and aluminum oxide (Al2O3).
Findings
The pressure and temperature distribution across the lubricant film in the clearance space of journal bearing and static performance characteristics are calculated.
Originality/value
The computed results show that addition of nanoparticles in the lubricant influences the performance characteristics considerable in thermoviscous case than non-thermoviscous case.
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Nurul Farhanah Azman, Syahrullail Samion, Muhammad Amirrul Amin Moen, Mohd Kameil Abdul Hamid and Mohamad Nor Musa
The purpose of this paper is to investigate the anti-wear (AW) and extreme pressure (EP) performances of CuO and graphite nanoparticles as a palm oil additive.
Abstract
Purpose
The purpose of this paper is to investigate the anti-wear (AW) and extreme pressure (EP) performances of CuO and graphite nanoparticles as a palm oil additive.
Design/methodology/approach
In this study, the AW and EP performances of CuO and graphite nanoparticles as additives in palm oil were evaluated using four ball tribotester in accordance to ASTM D4172 and ASTM D2783, respectively. The wear worn surfaces of the steel balls were analysed using high resolution microscope.
Findings
The results obtained demonstrate that CuO and graphite nanoparticles improved the AW and EP performances of the palm oil up to 2.77 and 12 per cent, respectively. The graphite nanoparticles provide better AW and EP performance than that of CuO nanoparticles.
Originality/value
This demonstrates the potential of CuO and graphite nanoparticles for improving AW and EP performances of palm oil base lubricant. Different morphology of nanoparticles will affect the AW and EP performances of nanolubricants.
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Gitesh Kumar, Hem Chander Garg and Ajay Gijawara
This paper aims to report the friction and wear characteristics of refined soybean oil (RSBO) blended with copper oxide (CuO) nanoparticles and zinc dialkyldithiophosphate (ZDDP…
Abstract
Purpose
This paper aims to report the friction and wear characteristics of refined soybean oil (RSBO) blended with copper oxide (CuO) nanoparticles and zinc dialkyldithiophosphate (ZDDP) as additives.
Design/methodology/approach
Four different concentrations 0.04, 0.05, 0.1 and 0.2 Wt.% of CuO nanoparticles were added with ZDDP in RSBO. The friction and wear characteristics of lubricants have been investigated on a pin-on-disc tribotester under loads of 120 and 180 N, with rotating speeds of 1,200 and 1,500 rpm in half hour of operating time. The dispersion stability of CuO nanoparticles has been analyzed using ultraviolet visible (UV-Vis) spectroscopy. The wearout surface of pins has been examined by using a scanning electron microscope.
Findings
The results revealed that there is a reduction in the friction and wear by the addition of CuO nanoparticles and ZDDP in RSBO. Coefficient of friction increases at a high sliding speed for RSBO with ZDDP. From UV-Vis spectroscopy, it is observed that 100 ml of oleic acid surfactant per gram of CuO nanoparticles has stable dispersion in RSBO.
Originality/value
The addition of ZDDP and CuO nanoparticles in RSBO is more efficient to reduce the friction and wear in comparison to base oil. The optimum concentration of CuO nanoparticles in RSBO is 0.05 Wt.%.