scholarly journals Role of Eco-Friendly Bio-Based Graphene-Oil Nanofluids on Friction Reduction for Wind Turbine Application

2021 ◽  
Vol 943 (1) ◽  
pp. 012012
Author(s):  
K P Ng ◽  
K W Liew ◽  
E Lim

Abstract Sustainable energy such as wind turbine is known as a green technology that minimize the carbon emission into environment. However, unwanted friction and wear in journal bearing of a wind turbine’s gearbox leads to reduction of power efficiency and increase the reliance onto fossil-fuel powered electricity. Lubricating oils are used in journal bearing to provide the hydrodynamic lubrication film. However, commercially available lubricants are petroleum-based, which are non-replenishable and toxic. Thus, the bio-degradable vegetable oil, high oleic palm oil-based methyl ester (high oleic POME) was used as a base oil synthesized with graphene nanoplatelets (GNP), multi-walled carbon nanotubes (MWCNT) and nanostructured graphite (NSG), respectively, to enhance the friction and wear reduction. The tribological performance of each type of bio-based graphene-oil nanofluid was studied using pin-on-ring tribo-tester. It is concluded that NSG in high oleic POME shows 52.03% friction coefficient reduction and 59.27% pin specimen weight loss reduction. With this significant friction and wear reduction, power efficiency of wind turbine will be improved significantly. Thus, the reliance of society depending on fossil-fuel powered electricity can be reduced and minimize the carbon emission into the environment.

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Wei Dai ◽  
Kyungjun Lee ◽  
Alexander M. Sinyukov ◽  
Hong Liang

In this research, rheological and tribological performance of additive V2O5 nanoparticles in a light mineral oil has been investigated. For rheological performance, the addition of 0.2 wt. % V2O5 could reduce the viscosity of the base oil for 6%. Considering the overall friction reduction in boundary, mixed, and hydrodynamic lubrication regimes, that with 0.1 wt. % V2O5 exhibited the best effect. Friction coefficient of base oil could be reduced by 33%. In terms of wear, the addition of 0.2 wt. % V2O5 showed the lowest wear rate, which is 44% reduction compared to base oil. Through Raman spectrum and energy dispersive spectroscopy (EDS) analysis, it was found that V2O5 involved tribochemical reaction during rubbing. Vanadium intermetallic alloy (V–Fe–Cr) was found to enhance the antiwear performance. This research revealed that V2O5 nanoparticles could be an effective additive to improve tribological performance.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 732
Author(s):  
Yeoh Jun Jie Jason ◽  
Heoy Geok How ◽  
Yew Heng Teoh ◽  
Farooq Sher ◽  
Hun Guan Chuah ◽  
...  

This study investigated the tribological behaviour of Pongamia oil (PO) and 15W–40 mineral engine oil (MO) with and without the addition of graphene nanoplatelets (GNPs). The friction and wear characteristics were evaluated in four-ball anti-wear tests according to the ASTM D4172 standard. The morphology of worn surfaces and the lubrication mechanism of GNPs were investigated via SEM and EDS. This study also focuses on the tribological effect of GNP concentration at various concentrations. The addition of 0.05 wt % GNPs in PO and MO exhibits the lowest friction and wear with 17.5% and 12.24% friction reduction, respectively, and 11.96% and 5.14% wear reduction, respectively. Through SEM and EDS surface analysis, the surface enhancement on the worn surface by the polishing effect of GNPs was confirmed. The deposition of GNPs on the friction surface and the formation of a protective film prevent the interacting surfaces from rubbing, resulting in friction and wear reduction.


Materials ◽  
2016 ◽  
Vol 9 (11) ◽  
pp. 950 ◽  
Author(s):  
Auezhan Amanov ◽  
Byungmin Ahn ◽  
Moon Lee ◽  
Yongho Jeon ◽  
Young-Sik Pyun

2019 ◽  
Vol 895 ◽  
pp. 212-217
Author(s):  
Deepak ◽  
T.P. Jeevan ◽  
S.R. Jayaram

Lubricants have a very crucial role in machinery industry for friction reduction and wear reduction between two relatively moving parts. The current study enlightens the works from various authors on evaluating the tribological behavior of environment friendly vegetable based oils as emerging biodegradable lubricants. The influences of the vegetable oils on friction and wear performance using different Tribometers were reported. The review focuses efforts on the development and commercialization of these vegetable based oils as industrial lubricants for manufacturing industries, mainly, metal forming and metal cutting. The review reveals that, many vegetable oils can be used as industrial lubricant, due to their exemplary attributes in terms of friction and wear reduction, which would help to decrease the universal demand of commercial lubricants which are based on petroleum resources to a great extent.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3227
Author(s):  
Slawomir Wos ◽  
Waldemar Koszela ◽  
Pawel Pawlus

The constant development of environmental protection causes the necessity to increase the efficiency of machines. By increasing the efficiency of machines, energy losses can be limited, leading to lower energy consumption. Friction reduction leads to an increase in efficiency and a decrease in wear. In this paper, selected surface texturing methods, such as burnishing and abrasive jet machining, with their limitations are presented. Thanks to those processes, various surface textures can be obtained. Examples of applications of these methods for friction and wear reduction are shown.


Author(s):  
Wenyang Zhang ◽  
Muhammad P. Jahan ◽  
Ajay P. Malshe

MoS2 multi-component nanolubrication system showed significant friction and wear reduction (more than 30% in friction reduction and 50% in wear reduction) in sliding steel surfaces, especially under mixed and boundary lubrication conditions [1–3]. It is believed that the formation of tribofilms in MoS2 multi-component nanolubrication system under different lubrication regimes is the primary reason for reduced friction and wear. To investigate the in-depth science of the tribo-chemical interface formed by MoS2 multicomponent nanolubrication system, it is necessary to study the chemical states of tribofilm during its evolution (generation ↔ regeneration) process at tribo-interfaces. Tribofilms from various lubrication regimes were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), Raman microscope, and X-ray photoelectron spectroscopy (XPS) techniques to study the morphology, chemical composition, elemental distribution, and chemical bonding of tribo-chemical surface, respectively. Besides the evolution process, the characterization of tribofilms also reveals the possibility of forming new meta-stable phases (chemical compounds) after tribological testing. Patchy tribofilms and progressive tribofilms have been observed from the SEM analysis and the EDX results showed existence of Mo-S-P as the composition of tribo-chemical films. The Raman spectroscopy analysis of tribofilms showed significant difference (such as formation of poly-molybdates) in chemical information of nanolubricants and tribofilms, which is an indication of the formation of friction polymer [4–5]. Additionally, phosphates and oxides, acting as components of surface protecting layer of tribofilms, have been found on surface by XPS technique. Moreover, MoS2 nanoparticles are found to navigate into surface asperities to protect the contacting surfaces. The results (information about the chemical states of the tribofilm) obtained from different characterization techniques can be used to explain the mechanism of friction and wear reduction associated with MoS2 multi-component nanolubrication system that has been reported in the literature.


Author(s):  
B. P. Khozyainov

The article carries out the experimental and analytical studies of three-blade wind power installation and gives the technique for measurements of angular rate of wind turbine rotation depending on the wind speeds, the rotating moment and its power. We have made the comparison of the calculation results according to the formulas offered with the indicators of the wind turbine tests executed in natural conditions. The tests were carried out at wind speeds from 0.709 m/s to 6.427 m/s. The wind power efficiency (WPE) for ideal traditional installation is known to be 0.45. According to the analytical calculations, wind power efficiency of the wind turbine with 3-bladed and 6 wind guide screens at wind speedsfrom 0.709 to 6.427 is equal to 0.317, and in the range of speed from 0.709 to 4.5 m/s – 0.351, but the experimental coefficient is much higher. The analysis of WPE variations shows that the work with the wind guide screens at insignificant average air flow velocity during the set period of time appears to be more effective, than the work without them. If the air flow velocity increases, the wind power efficiency gradually decreases. Such a good fit between experimental data and analytical calculations is confirmed by comparison of F-test design criterion with its tabular values. In the design of wind turbines, it allows determining the wind turbine power, setting the geometrical parameters and mass of all details for their efficient performance.


2021 ◽  
Vol 11 (2) ◽  
pp. 779
Author(s):  
Dimitrios Dardalis ◽  
Amiyo Basu ◽  
Matt J. Hall ◽  
Ronald D. Mattthews

The Rotating Liner Engine (RLE) concept is a design concept for internal combustion engines, where the cylinder liner rotates at a surface speed of 2–4 m/s in order to assist piston ring lubrication. Specifically, we have evidence from prior art and from our own research that the above rotation has the potential to eliminate the metal-to-metal contact/boundary friction that exists close to the piston reversal areas. This frictional source becomes a significant energy loss, especially in the compression/expansion part of the cycle, when the gas pressure that loads the piston rings and skirts is high. This paper describes the Diesel RLE prototype constructed from a Cummins 4BT and the preliminary observations from initial low load testing. The critical technical challenge, namely the rotating liner face seal, appears to be operating with negligible gas leakage and within the hydrodynamic lubrication regime for the loads tested (peak cylinder pressures of the order of 100 bar) and up to about 10 bar BMEP (brake mean effective pressure). Preliminary testing has proven that the metal-to-metal contact in the piston assembly mostly vanished, and a friction reduction at idle conditions of about 40% as extrapolated to a complete engine has taken place. It is expected that as the speed increases, the friction reduction percentage will diminish, but as the load increases, the friction reduction will increase. The fuel economy benefit over the US Heavy-Duty driving cycle will likely be of the order of 10% compared to a standard engine.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1336
Author(s):  
Jorge Caessa ◽  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Albano Cavaleiro

Friction and wear contribute to high energetic losses that reduce the efficiency of mechanical systems. However, carbon alloyed transition metal dichalcogenide (TMD-C) coatings possess low friction coefficients in diverse environments and can self-adapt to various sliding conditions. Hence, in this investigation, a semi-industrial magnetron sputtering device, operated in direct current mode (DC), is utilized to deposit several molybdenum-selenium-carbon (Mo-Se-C) coatings with a carbon content up to 60 atomic % (at. %). Then, the carbon content influence on the final properties of the films is analysed using several structural, mechanical and tribological characterization techniques. With an increasing carbon content in the Mo-Se-C films, lower Se/Mo ratio, porosity and roughness appeared, while the hardness and compactness increased. Pin-on-disk (POD) experiments performed in humid air disclosed that the Mo-Se-C vs. nitrile butadiene rubber (NBR) friction is higher than Mo-Se-C vs. steel friction, and the coefficient of friction (CoF) is higher at 25 °C than at 200 °C, for both steel and NBR countersurfaces. In terms of wear, the Mo-Se-C coatings with 51 at. % C showed the lowest specific wear rates of all carbon content films when sliding against steel. The study shows the potential of TMD-based coatings for friction and wear reduction sliding against rubber.


2021 ◽  
Vol 69 (2) ◽  
Author(s):  
Jia Ren ◽  
Kuiliang Gong ◽  
Gaiqing Zhao ◽  
Wenjing Lou ◽  
Xinhu Wu ◽  
...  

AbstractThe tribological performances of perfluoroalkylpolyethers (PFPE) with graphene (Gr), WS2, and the mixture of Gr and WS2 (Gr + WS2) before and after ultraviolet (UV), atomic oxygen (AO), and proton (Pr) irradiations were investigated. The composition and structure of PFPE, Gr, WS2, and Gr + WS2 were also analyzed to understand the effects of irradiation on the tribological behaviors of PFPE with additives. The results indicated that serious deterioration and degradation of PFPE took place and Gr was transformed to amorphous carbon after Pr irradiation, and surface oxidation of WS2 occurred under the irradiations of AO and Pr. Moreover, compared to PFPE and PFPE additized with Gr and WS2, PFPE with the addition of Gr + WS2 exhibited excellent friction and wear reduction before and after UV and AO irradiations. Graphical Abstract


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