Ramesh Chandra Singh | Delhi Technological University, Delhi, India (original) (raw)

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Papers by Ramesh Chandra Singh

Piston in the internal combustion (IC) engine is robust, dynamically loaded tribo-pair that recip... more Piston in the internal combustion (IC) engine is robust, dynamically loaded tribo-pair that reciprocates continuously at varying temperature. Study has been made by various researchers on piston design, dynamics, fatigue and wear at the interface with other element in contact along with their effects on IC engines. It was found that the friction coefficient increases with increasing surface roughness of liner surface and thermal performance of the piston increases with increased coating thickness. The free material liberated due to deep scoring between the piston and liner snowballs, leads to seizure failure.
Keywords: Piston, Tribo-pair, IC Engines, Fatigue, Wear.

The Paper incorporates the experimental studies carried out for assessing the tribological perfor... more The Paper incorporates the experimental studies carried out for assessing the tribological performance of Aluminium at the sliding contacts with mild steel plate, using a pin-on-disk tribometer as per ASTM-G 99. The study has been done in order to explore the friction and wear behaviors at the interface of tribo-pair. The tribological properties as coefficient of friction and specific wear rate of aluminium 6061are investigated. The Tribological tests are carried out at 500, 1000, 1500 rpm for 1000 meters in dry condition based on Response Surface Methodology. Track diameter, rotating speed and normal load are considered as the design parameters. Using central composite design, the problem is converted into single response optimization problem and the optimum combination of design parameters are found as 50mm track diameter, 500 rpm of rotating speed and 0.5 kg of normal load. The ANOVA result shows that the rotational speed is the most significant factor, followed by load and Track diameter for co-efficient of friction. Whereas the Track diameter is the most significant factor, followed by rotating speed and normal load for specific wear rate. Finally, microscopic images are investigated to identify the wear mechanism.

The need for advanced lubricants is increasing rapidly due to the current wide range of operation... more The need for advanced lubricants is increasing rapidly due to the current wide range of operational usage, i.e., high loads and speeds of motion between friction pairs, broader temperature range, and the overall requirements for increased reliability and service life of machinery. It is essentially important to develop specialized anti-friction and anti-wear materials that will help in preventing wear and decreasing friction, thereby saving fuel and electricity. Simultaneously, such materials are also expected to reduce vibration, noise and maintenance of machine parts. Thus, the research into extending the service life of such materials continues to be imperative. Nanoparticles (NPs) present a novel approach in this regard, as they can be used in lubricants in between two mating contact surfaces as a third body. When compared with the widely used conventional micro-particles for tribological applications, NPs have unique features owing primarily to their much higher specific surface area. This is true for studies of both nanostructured coatings of friction surfaces as well as for new lubricant compositions containing Nanoparticles. When compared to a pure fluid, this category of fluids containing nanoparticles (1-100 nm) has displayed fascinating behavior during experiments including augmented heat transfer coefficient and higher thermal conductivity. The products so developed can find applications in metal working fluids, industrial gear oils, and automotive gear lubricants, either alone or in formulations. Present research investigates the influence of NPs as lubricant additive on the relative motion of a plane surface over the other having circular surface in contact. A pin-on-disk setup as per ASTM G99 has been used to conduct the experiments in starved and fully flooded conditions at various loads and relative speeds at the pin and disc contact. The lubricant SAE 20W-40 with nano-additives has been used to study the influence on friction and specific wear rate at the interface. Based on the experiments, tribological behavior of lubricant with NPs has been compared with the lubricant without NPs. The coefficient of friction and specific wear rate were found to be decreased in lubricant containing NPs. The addition of NPs to the lubricant SAE 20W40 has proved to be profoundly promising in reducing the friction and specific wear rate.

The economics of operating internal combustion engines in cars, buses and other automotive equipm... more The economics of operating internal combustion engines in cars, buses and other automotive equipment is heavily affected by friction and wear losses caused by abrasive contaminants. As such, dust is a universal pollutant of lubricating oils. Road dust consists of depositions from vehicular and industrial exhausts, tire and brake wear, dust from paved roads or potholes, and from construction sites.

An experimental study has been carried out to investigate the performance of a single cylinder ai... more An experimental study has been carried out to investigate the performance of a single cylinder air cooled diesel engine fuelled with neem oil-diesel blend (5%, 10%, 15% and 20% by volume) and the results are compared with baseline data of diesel. Brake thermal efficiency of the engine with 5% neem oil blend was found to be marginally higher than neat diesel operation at all loads indicating better combustion due to dissolved oxygen. However, with further increase in percentage of neem oil, brake thermal efficiency of the engine reduced significantly at higher loads possibly due to increased viscosity of the fuel impinging proper combustion. Brake specific energy consumption happen to be the lowest for 5% neem oil blend at all loads, however with subsequent increase in percentage of neem oil, full load brake specific energy consumption became lower at part loads and higher at full loads as compared to neat diesel operation. Smoke opacity of 5% blend was comparable to baseline data of diesel, but it increased substantially at higher blends. With increase in percentage of neem oil in the test fuel sample the exhaust temperature showed a downward turn reflecting a comparatively improved nitrogen oxides emission tendency and reduced thermal loads. Based on this experimental study, it is envisaged that in rural/agriculture sector of India where neem oil can be available at economical cost, 5% neem oil blend may be a good substitute for mineral diesel which in turn can save considerable amount of forex outflow for equivalent crude oil import.

This study presents performance behaviors of a commercial diesel engine fueled with diesel and Ja... more This study presents performance behaviors of a commercial diesel engine fueled with diesel and Jatropha based biodiesel (B100) at various loads (up to 100%) and compared using standard (conventional) and three new face profile designs (I, II & III) of piston rings. Face profiles of piston rings had considerable impact on engine's brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and mass flow rate, irrespective of fuels used. BTE of engine fueled with diesel increases 2-8% with new face profile design (III) of piston rings in comparison to standard (conventional) piston rings. BTE enhances 8-16% when engine is fueled with biodiesel using face profile design (III) on piston rings. Corresponding to increase in BTE, recorded reduction in BSFC (biodiesel) is 28-34%. Industrial application of the results of present study may be useful in saving and conservation of fuels.

Roller bearing defect is a major factor of failure in rotating machinery that affects proper func... more Roller bearing defect is a major factor of failure in rotating machinery that affects proper functioning of system which results in substantial time and economic losses. Therefore, condition monitoring of roller bearing is important and the study of severity of defects are necessarily required in order to avoid catastrophic consequences. Defects monitoring during dynamic loading conditions of rotational machineries with the use of contactless, non-destructive infrared thermographic method is proposed. By using a rotating ball bearing, passive thermographic experiment was performed as an alternative technique to proceed the condition monitoring. Based on the results, the temperature characteristics of the ball bearing under dynamic loading conditions were analyzed thoroughly. Also, a comparison of these results was done for different bearings with characteristic defects. As a result, it was confirmed that infrared thermography method could be adopted to monitor and diagnose the faults by evaluating quantitatively and qualitatively the temperature characteristics according to the condition of the ball bearing.

The present research has been done to investigate the influence of the relative motion of a plane... more The present research has been done to investigate the influence of the relative motion of a plane surface with the other having micro-circular dimples throughout the contact. Using pin-on-disk setup, experiments have been carried out to study the influence of micro-dimple area density on friction and specific wear rate at the interface of two materials. Circular dimples are distributed in spiral array on the disk face. Based on the experiments, better tribological results have been achieved in the starved boundary lubrication mode.

Piston rings are vital components in the internal combustion (IC) engines having reciprocative mo... more Piston rings are vital components in the internal combustion (IC) engines having reciprocative motion. The oil film thichness plays important roll and finally affects the performance of engine. Surface roughness of tribo pair material at the junction produce friction and it varies throughout the stroke length of piston. Loss of power in lubrication has the shear force due to boundary conditions. The tribological performance in IC engine can be understood when friction and wear are considered. It is also necessary to study the factors influencing reliability and performance along with wear . From the view point of tribo element it is very important to know the specific load, speeds and temperatures for the major components of engine like piston assembly, valve train, the journal bearing and lower viscocity engine oil for lubrication. This paper explains the studies made on Cylinder liner and Piston rings interface. Published data on friction and wear have been collected from various researchers concluded from their experiments and experiences.