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Physicochemical and Thermal Properties of Biodiesel
Published in Anand Ramanathan, Babu Dharmalingam, Vinoth Thangarasu, Advances in Clean Energy, 2020
Anand Ramanathan, Babu Dharmalingam, Vinoth Thangarasu
The characteristics of the friction and wear of the biodiesel and fuel samples were determined using a four-ball wear tester (DUCOM, TR-30L-IAS). As per the ASTM D2266 standard, tribological tests were done. Lubricants or lubricity of any new grease was commonly tested with the help of four-ball tribotesting. The setup contains four balls, where three balls are held in the lubricant cup rigidly against each other with the help of a clamping ring and the leftmost ball is bonded with a rotating chuck kept above these balls. Before starting the experimental setup, the lubricant cup and steel balls were cleaned with toluene and then dried. About 10 mL of the fuel sample to be tested was poured in the lubricant cup, and it should be ensured that the sample has covered the three balls at the bottom and to the height of 3 mm over the balls. The test was run for 60 min with a chuck speed of 1200 rpm and a 40 kg load, both of which were held constant. After the test run, three stationary balls were bought together for measurement wear scar diameter using scanning electron microscopy analysis. A friction-measuring device uses a calibrated spring to measure the frictional torque. The following equation was used for the calculation of the coefficient of friction. Coefficientoffriction(µ)=T63Wr
Enhancement in the Friction and Wear Resistance of Low Carbon Chromium Steel and Load Carrying Capability of MIL-PRF-23699 Grade Lubricant Using h-BN Nanoadditives for Aerospace Applications
Published in Tribology Transactions, 2023
Senthil Kumar M., Elayaperumal A., Sankaraiah M., Sathyanarayana H.
The frictional torque measured in the four ball test at different loads under the BL and h-BN NL conditions is shown in Fig. 14. The low frictional torque was exhibited for the chrome steel balls at load of 800 N in both BL and h-BN NL. The primary reason for low frictional torque was likely due to lubricant film formation. The lubricant film has minimized the asperity–asperity contacts, which eventually reduced the frictional torque. The chrome steel balls depicted an increasing trend in the frictional torque in both BL and h-BN NL with the increase in load. This was because of the shearing of the lubricant film caused by the stress developed at higher load conditions. The sustainability of the lubricant film mainly depends on many factors like viscosity, frictional condition, applied load, and sliding velocity. Importantly, the contact pressures at higher load conditions could possibly lead to the asperities contacting (metal to metal) and increasing the frictional torque. Accordingly, the high contact pressure developed at higher load conditions has increased the asperities' contact and led to a higher frictional torque for the chrome steel balls in both BL and h-BN NL.
A Mixed Lubrication Model for Lip Seals Based on Deterministic Surface Microdeformation
Published in Tribology Transactions, 2021
Bingqi Jiang, Fei Guo, Tao Ma, Xiaohong Jia, Ning Zhao, Yuming Wang
The friction torques and leakage rates were measured using the test bench shown in Fig. 5. The lip seals were installed forward and in reverse to investigate the application scope of the reverse pumping mechanism. The rotary oil seal used in the bench test was 65 mm in diameter. The leaking lubricant oil was collected by an oil-collecting cup and measured using a precision electronic scale with a resolution of 0.01 g. In order to measure the friction torque, a static torque sensor with the resolution of 0.001 N m and measuring range of 10 N m was used. One side of the static torque sensor was connected to the chamber and the other side was fixed to the support seat. The bench test was carried out under hydraulic oil (ISO 32) lubrication condition and at room temperature (25 °C).
Valvetrain Friction and Wear Performance of Polyalkylene Glycol Engine Oils
Published in Tribology Transactions, 2018
A. Gangopadhyay, D. G. McWatt, R. J. Zdrodowski, S. J. Simko, S. L. Peczonczyk, J. Cuthbert, E.D. Hock
The wear protection capability of the oils was evaluated with another motored valvetrain rig using a radionuclide technique where the entire top surface of a tappet and the entire width of the cam nose and 5 mm on either side of the nose were activated. The tappet surface was activated with Co56 and the cam lobe surface was activated with Co57 by bombarding the surfaces with a proton beam. The initial radioactivity was 17–22 MBq/mg. The depth of the activated surface was about 15 μm. The wear evaluations were conducted on a motored valvetrain rig where a single cam lobe rotated against a single tappet. One cam lobe was cut from a production V6 engine intake camshaft, bored, and press-fitted onto a shaft, which was driven by a 2 hp motor. A production tappet was mounted on a production spring in the same manner as in an engine. The tappet reciprocated inside an aluminum sleeve made of the engine material and maintained the same clearance between the tappet and the sleeve as in the engine. The tappet was in contact with a steel valve having an equivalent mass of an intake valve. The contact area of the tappet and the cam lobe was lubricated by a jet of engine oil at 85 psi and 95°C. The camshaft was rotated at 500, 1,000, and 1,500 rpm for a total of 100 h. The rig set up is shown in Fig. 4a and the cam and tappet contact is shown in Fig. 4b. The centerline average surface roughness of the cam lobes and tappets were 0.08–0.13 μm and 0.014–0.019 μm, respectively. Friction torque was measured by an in-line torque meter. In addition to PAG oils, fresh and vehicle-aged GF-5 SAE 5W-20 oils were also evaluated.