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Viewing 151 to 180 of 110083
2017-09-04
Technical Paper
2017-24-0139
Francesco Barba, Alberto Vassallo, Vincenzo Greco
The aim of the present study is to improve the effectiveness of the engine and aftertreatment calibration process through the critical evaluation of several methodologies available to estimate the soot mass flow produced by diesel engines and filtered by Diesel Particulate Filters (DPF). In particular, the focus of the present study has been the development of a reliable simulation method for the accurate prediction of the engine-out soot mass flow starting from Filter Smoke Number (FSN) measurements executed in steady state conditions, in order to predict the DPF loading considering different engine working conditions corresponding to NEDC and WLTP cycles. In order to achieve this goal, the study was split into two parts: - Correlation between ‘wet soot’ (measured by soot filter weighing) and the ‘dry soot’ (measured by the Micro Soot Sensor MSS).
2017-09-04
Technical Paper
2017-24-0138
Giovanni Meccariello, Livia Della Ragione
In the context of a transport sustainability, some solutions could be proposed from the integration of many disciplines, architects, environmentalists, policy makers, and consequently it may be addressed with different approaches. These solutions would be apply at different geographical levels, i.e. national, regional or urban scale. Moreover, the assessment of cars emissions in real use plays a fundamental role for their reductions. This is also the direction of the new harmonized test procedures (WLTP). Furthermore, it is fundamental to keep in mind that the new WLTC cycle will reproduce a situation closer to the reality respect to the EUDC/NEDC driving cycle. In this paper, we will be focused on vehicle kinematic evaluation aimed at valuation of traffic situation and emissions.
2017-09-04
Technical Paper
2017-24-0144
Carlo Beatrice, Maria Antonietta Costagliola, Chiara Guido, Pierpaolo Napolitano, Maria Vittoria Prati
Diesel particulate filter (DPF) is the most effective emission control device for reducing particle emissions (both in mass, PM, and number, PN) from diesel engines, however many studies have reported elevated emissions of nanoparticles (<50 nm) during its regeneration. In this paper the results of an extensive literature search are presented (about 150 reports and scientific papers). During DPF active regeneration most of the literature studies show an increase in the number of the emitted nanoparticles of about 2-3 orders of magnitude compared to the normal operating conditions. Many factors can influence their amount, size distribution, chemical-physical nature (volatiles, semi-volatiles, solid) and the duration of the regenerative event: i.e. DPF load and thermodynamic conditions, lube and fuel sulfur content, engine operative conditions, PN sampling and measurement methodologies.
2017-09-04
Technical Paper
2017-24-0145
Marco Piumetti, Debora Fino, Nunzio Russo, Samir Bensaid, Melodj Dosa
A set of CeO2 nanocatalysts with different structural properties (nanocubes, nanorods, high-surface area CeO2) was prepared to investigate the shape-dependency activity for two oxidation reactions: the soot combustion under different soot-catalyst contact conditions (namely, in “loose” and “tight” conditions) and the CO oxidation. The physico-chemical properties of the prepared materials were investigated by complementary techniques (XRD, N2-physisorption at -196 °C, H2-TPR, FESEM, TEM, micro-Raman, FT-IR, XPS). As a whole, the best performances in terms of soot combustion have been achieved for the CeO2-nanocubes (SBET = 4 m2g-1), due to the abundance of highly reactive (100) and (110) exposed surfaces. On the other hand, better results in terms of the onset of soot oxidation (T10%) have been obtained for high-surface-area materials (SBET = 75 m2g-1), thus reflecting the key role of the surface area at low reaction temperature.
2017-09-04
Technical Paper
2017-24-0162
Harald Stoffels, Jens Dunstheimer, Christian Hofmann
The application of a turbocharger, having an electric motor/generator on the rotor was studied focusing on the electric energy recuperation on a downsized gasoline internal combustion engine, using 1D-calculation approaches. Using state-of-the art optimization techniques, the settings of the valve timing was optimized to cater for a targeted pre-turbine pressure and certain level of residual gases in the combustion chamber to avoid abnormal combustion events. Subsequently, a steady-state map of the potential of electric energy recuperation was performed while considering in parallel different efficiency maps of the potential generator and a certain wastegate actuation strategy. Moreover, the results were taken as input to a WLTP cycle simulation in order to identify any synergies with regard to fuel economy.
2017-09-04
Technical Paper
2017-24-0168
James W.G. Turner, James P. Lewis Monsma
Modern automotive engines almost exclusively operate on the 4-stroke Otto cycle and utilize poppet valves for gas exchange. This state of affairs has not always been the case, however, and one unusual and relatively successful technology that was once in mass production (albeit in piston aero engines) was the Burt-McCollum single sleeve valve. This paper investigates the timing and angle-area of a Bristol Centaurus engine cylinder, which utilized such a single sleeve valve for gas exchange, using some modern tools. A comparison with poppet valve angle-areas is made. Finally, the results are also used to study the potential of variable valve timing and the interaction with compression ratio of a single sleeve mechanism.
2017-09-04
Technical Paper
2017-24-0167
Enrico Mattarelli, Carlo Rinaldini, Tommaso Savioli, Giuseppe Cantore, Alok Warey, Michael Potter, Venkatesh Gopalakrishnan, Sandro Balestrino
A CFD study on a 2-stroke (2-S) opposed piston high speed direct injection (HSDI) Diesel engine is reported in this work. The engine main features (bore, stroke, port timings, et cetera) were defined in a previous stage of the project, with the support of CFD-1D engine simulations and empirical hypotheses. The current analysis is focused on the assembly made up of scavenge ports, manifold and cylinder. The first step of the study consisted in the construction of a parametric mesh on a simplified geometry. Two geometric parameters and 3 different operating conditions were considered. A CFD-3D simulation by using a customized version of the KIVA-4 code was performed on a set of 243 different cases, sweeping all the most interesting combinations of geometric parameters and operating conditions. The post-processing of this huge amount of data allowed us to define the most effective geometric configuration, named baseline.
2017-09-04
Technical Paper
2017-24-0123
Christopher Eck, Futoshi Nakano
Small commercial vehicles (SCV) with Diesel engines require efficient exhaust aftertreatment systems to reduce the emissions while keeping the fuel consumption and total operating cost as low as possible. To meet current emission legislations in all cases, a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) and some NOx treatment device (e.g. a lean NOx trap or selective catalytic reduction, SCR) are required. Creating a cost-effective SCV also requires to keep the cost for the aftertreatment system as low as possible because the contribution to total vehicle cost is high. By using more sophisticated and more robust operating strategies and control algorithms, the hardware cost can be reduced. To keep the calibration effort at a low level, it is necessary to apply only algorithms which have a time-efficient calibration procedure. This paper will focus on the active regeneration of the DPF.
2017-09-04
Technical Paper
2017-24-0131
Sergio Mario Camporeale, Patrizia D. Ciliberti, Antonio Carlucci, Daniela Ingrosso
The incoming PostEuro6 regulation and the on-board diagnostics -OBD- pushes the research activity towards the set-up of even more efficient after treatment systems. Nowadays, the most common after treatment system for NOx reduction is the selective catalytic reactor –SCR- . This system requires as an input the value of engine out NOx emission –raw- in order to control the Urea dosing strategy. In this work, a grey box NOx raw emission model based on in-cylinder pressure signal (ICPS) is validated on two standard cycles: MNEDC and WLTC using an EU6 engine at the test bench. The overall results show a maximum relative error of the integrated cumulate value integral of 12.8% and 17.4% for MNEDC and WLTC respectively. In particular, the instantaneous value of relative error is included in the range of ± 10% in the steady state conditions while during transient conditions is less than 20% mainly.
2017-09-04
Technical Paper
2017-24-0178
Katarzyna E. Matusik, Daniel J. Duke, Alan L. Kastengren, Christopher F. Powell
The present work is motivated by a need to understand the effects of the ambient environment on the sparking behavior in a spark ignition engine. Measurements of the projected density of the plasma formed by a conventional transistorized coil ignition system were conducted at the 7-BM beamline of the Advanced Photon Source at Argonne National Laboratory. A spark plug with a 1 mm gap was mounted in a grounded, pressurized chamber that was continually purged by a constant flow of gas. The x-ray radiography technique was used to obtain a 2D map of the projected density of the ambient gas during the transition and glow discharge phases of the spark plug at high temporal and spatial resolution. The projected density provides a measure of the amount of energy that is deposited into the environment by the sparking event. In order to examine the effects of the surrounding gas on the emitted thermal energy, experiments were conducted for a range of ambient densities and gas compositions.
2017-09-04
Technical Paper
2017-24-0179
Marco Tonetti, Giorgio Rustici, Massimo Buscema, Luca Ferraris
Final Euro6d emission legislation with the new homologation cycle and Real Driving Emission requirements has set a strong challenge for the ICE Passenger Car applications. Thanks to their well-known low fuel consumption characteristics, Diesel Engines can play a key role for the fulfillment of the European 2020 CO2 fleet target but need to confirm their capability to fully control noxious emissions even in extreme operating conditions, while restraining the overall engine costs and complexity. CO2 and NOx emissions reduction are considered the main drivers for diesel engine evolution. In this perspective, Exhaust Gas After-treatment and Combustion System have been identified as the two main technology aspects to be developed. The purpose of this paper is to describe the evolution paths of these two technologies and the results achieved so far in terms of noxious emissions reduction. A methodology has been developed to predict Diesel combustion evolution and its main characteristics.
2017-09-04
Technical Paper
2017-24-0140
Roberto Aliandro Varella, Gonçalo Duarte, Patricia Baptista, Pablo Mendoza Villafuerte, Luis Sousa
Due to the need to properly quantify vehicle emissions in real world operation, Real Driving Emissions (RDE) test procedures will be used for measuring gaseous emissions on new EURO 6 vehicles.at the RDE 1 & 2: Commission Regulation (EU) 2016/427 of 10 March 2016 amending Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles. Updated regulations have been enhanced to define RDE tests boundaries and data analysis procedures, in order to provide an accurate way to obtain representative results. The boundary conditions defined for vehicle testing include external atmospheric temperature, which can range from 0ºC to around 30ºC, for moderate conditions and -7oC up to 35oC for extended conditions in RDE tests. As a result of this range of possible test ambient temperature, pollutant emissions and energy consumption can vary considerably.
2017-09-04
Technical Paper
2017-24-0032
Gilles Decan, Stijn Broekaert, Tommaso Lucchini, Gianluca D'Errico, Jan Vierendeels, Sebastian Verhelst
The present work details a study of the heat flux through the walls of an internal combustion engine. The determination of this heat flux is an important aspect in engine optimization, as it influences the power, efficiency and the emissions of the engine. Therefore, a set of simulation tools in the OpenFOAM® software has been developed, that allows the calculation of the heat transfer through engine walls for ICEs. Normal practice in these types of engine simulations is to apply a wall function model to calculate the heat flux, rather than resolving the complete thermo-viscous boundary layer, and perform simulations of the closed engine cycle. When dealing with a complex engine, this methodology will reduce the overall computational cost. It however increases the need to rely on assumptions on both the initial flow field and the behavior in the near-wall region.
2017-09-04
Technical Paper
2017-24-0017
Emanuele Servetto, Andrea Bianco, Gennaro Caputo, Giuseppe Lo Iacono
Large pressure pulsations and a non-uniform distribution of charge air temperature along the intake manifold were detected on a large-bore marine Dual-Fuel engine. These two phenomena were found to impact negatively on the knock resistance of individual cylinders, when the engine is operated in gas-mode. As it happens with marine gas engines, the cylinder most prone to knocking drives the engine tuning for all the others, thus reducing the overall fuel conversion efficiency. In order to effectively tackle this issue, a comprehensive study was carried out, which included both experimental testing and fluid-dynamics simulation. A detailed GT-POWER 1D engine model was built, representing the laboratory 8L (i.e. inline eight-cylinder) engine configuration. The model was extensively correlated against measurements at different speeds and loads and it proved capable of closely reproducing both the pressure fluctuations and the temperature gradient along the intake manifold.
2017-09-04
Technical Paper
2017-24-0159
Davide Di Battista, Marco Di Bartolomeo, Carlo Villante, Roberto Cipollone
Internal combustion engines is actually one of the most important source of pollutants and greenhouse gases emissions. In particular, on-the-road transportation sector has taken this environmental challenge and worldwide governments set up regulations in order to limit the emissions and fuel consumption from vehicles. Among the several technologies under development, an ORC unit bottomed exhaust gas seems to be very promising, but it still has several complications when it is applied on board of a vehicle (weight, encumbrances, backpressure effect on the engine, safety, reliability). In this paper, a comprehensive mathematical model of an ORC unit bottomed a heavy duty engine, used for commercial vehicle, has been developed. The model is completed with the sizing of the two exchangers involved in the ORC plant: the heat recovery vapor generator (HRVG) and the condenser.
2017-09-04
Technical Paper
2017-24-0158
Teresa Castiglione, Giuseppe Franzè, Angelo Algieri, Pietropaolo Morrone, Sergio Bova
The paper shows how specific requirements of the cooling system of an ICE can be met by actuating the coolant flow rate independently of engine speed, by means of an electric pump and of an ad-hoc developed control system. Given that the proposed methodology is valid for each condition, in the present paper the focus is on the engine operating under fully warmed conditions, with the aim to keep the wall temperature into the prescribed limits, with the lowest possible coolant flow rates. This goal is achieved by properly defining the controller parameters. The developed controller is based on the Robust Model Predictive Control approach, which makes use of a lumped parameter model of the engine cooling system. The model also includes the radiator-thermostatic valve-fan block and incorporates the nucleate boiling heat transfer regime.
2017-09-04
Journal Article
2017-24-0118
Marius Zubel, Stefan Pischinger, Benedikt Heuser
Within the cluster of excellence “Tailor-Made Fuels from Biomass” at the RWTH Aachen University, two novel biogenic fuels, namely 1-octanol and its isomer dibutyl ether (DBE), were identified and extensively analyzed in respect of their suitability for Diesel engine combustion. Both biofuels feature very different properties, especially regarding their ignitability. In previous works of the research cluster, promising synthesis routes with excellent yields for both fuels were found, using lignocellulosic biomass as source material. Both fuels were investigated as pure components in optical and thermodynamic single cylinder engines. For 1-octanol at lower part load, almost no soot emission could be measured, while with DBE the soot emissions were only about a quarter of that with conventional Diesel fuel. At high part load, the soot reduction of 1-octanol was more than 50% and for DBE more than 80 % respectively.
2017-08-29
Journal Article
2017-01-9000
Teresa Donateo, Antonio Ficarella
Abstract The design of a hybrid electric powertrain requires a complex optimization procedure because its performance will strongly depend on both the size of the components and the energy management strategy. The problem is particular critical in the aircraft field because of the strong constraints to be fulfilled (in particular in terms of weight and volume). The problem was addressed in the present investigation by linking an in-house simulation code for hybrid electric aircraft with a commercial many-objective optimization software. The design variables include the size of engine and electric motor, the specification of the battery (typology, nominal capacity, bus voltage), the cooling method of the motor and the battery management strategy. Several key performance indexes were suggested by the industrial partner. The four most important indexes were used as fitness functions: electric endurance, fuel consumption, take-off distance and powertrain volume.
2017-08-29
Journal Article
2017-01-9001
Hermann Ferschitz, Michael Wannemacher, Otto Bucek, Florian Knöbel, Wolfgang Breitfuß
Abstract RTA Rail Tec Arsenal Fahrzeugversuchsanlage GmbH has focused on the simulation of in-flight icing conditions since 2012. Following the successful implementation of the icing conditions specified in EASA CS-25 Appendix C, it was expected that the facility could also be used to simulate the SLD conditions required by EASA CS-25 Appendix O. This paper sets forth theoretical considerations concerning the selection of suitable nozzles and their operation in the existing facility. The transport of large droplets through the contraction nozzle was simulated using a CFD program. The results then served as a basis for deriving secondary droplet breakup. The validations carried out confirm the theoretical considerations and identify potential limits and open research questions.
2017-07-10
Technical Paper
2017-28-1955
Peda Chowdaiah Korlapati
In commercial vehicles, the greatest challenge is to improve the fuel economy and reduce emissions. The Aerodynamic drag control is one of the best ways to do the same. In Tractor-trailer assembly, the gap between the cabin and trailer and also rear end of the trailer are the critical areas which will affect the coefficient of drag drastically. Also the low pressure at the rear end of the trailer is one of the reasons for rear collision of trucks with other vehicles. The main objective of this work is to incorporate the inflatable boat tail at the rear-end of the trailer to reduce the drag coefficient and also to act as energy absorber in case of rear impact. The generic model of commercial vehicle with various boat tails is designed in CREO software and both steady and unsteady analysis are carried out by using ANSYS Fluent under various conditions from 0 to 6 degree wind directions.
2017-07-10
Technical Paper
2017-28-1962
Pervaz Ahmed Mouda, H Siddhi Jailani
Electro-Discharge Machining (EDM) is a suitable process used for machining very hard-to-cut materials. In EDM, the replica of electrode is obtained on the work piece by localized melting and vaporization of work piece material, but the electrode also tends to wear out to certain extent. In order to reduce the tool wear rate, the cryogenic treatment can be applied to the tool material. Cryogenic treatment is an ultra low temperature treatment technique which alters the properties of materials. In this paper, the effect of cryogenic treatment on a process parameter of EDM was studied. The Cryogenic treatment was applied to the copper electrode. Microstructure analysis was carried out using optical microscope. EDM experiment was conducted using untreated and cryogenic treated copper electrode and HSS tool steel as work piece material. Electrical resistivity was also measured.
2017-07-10
Technical Paper
2017-28-1963
Pavan Bharadwaja Bhaskar, S Srihari
In recent times control of emissions has been the major issue resulting strict emission norms. Oxides of nitrogen (NOx) reduction is a major concern over the years and diesel engine has big hand when compared to gasoline. Several promising techniques have been developed, homogeneous charge compression ignition (HCCI) is one of the effective ways to trim down the NOx emissions by keeping thermal efficiency identical to diesel engine. However, this concept lags in controlling CO and HC emissions. Methanol fuel blends are chosen as it significantly improves the combustion quality. Oxygen content in methanol drags attention as it can compensate HC and CO emissions caused by HCCI mode of combustion. In this work conventional diesel engine is converted into HCCI engine by mounting diesel vaporizer at inlet manifold to attain homogenous mixture. An experimental investigations have been carried out to analyse performance and emission characteristics using different methanol blends.
2017-07-10
Technical Paper
2017-28-1965
Selvam G., Surya Prakash V., Prince Arockia Doss S., Mohammed Zaheer A., Baskaran V
Lean approaches are being implemented in various manufacturing facilities across the globe. The application of lean approaches are extended to Body proto build shop to maximize the efficiency of the shop with lesser floor space and optimized equipment. Weld fixture, Weld equipment and assembly tools are the major tools required essentially for proto BIW assembly. This paper explains how the Weld equipment planning was carried out with lean approaches and implemented effectively in proto body assembly shop. The implemented lean concepts are compared with Italy and Japanese proto body build makers to validate the frugal planning of the facility for the said intent. The implemented facility is capable of producing more than a model at a time. Weld parameter selection for weld gun, gun movement to the fixture with minimized change over time, portable weld gun gantry are the lean approaches implemented.
2017-07-10
Technical Paper
2017-28-1964
Rajaganesh Ramamoorthy, T. Venkatesan, R. Rajendran
Machining of materials has received significant consideration due to the increasing use of machining processes in various industrial applications. In machining, the heat generated in the cutting zone during machining is critical in deciding the work piece quality. Lubricants are widely used to reduce the heat generation. Their usage poses threat to environment and health hazards. Hence, there is a need to identify eco-friendly and user-friendly alternatives to conventional cutting fluids. Modern tribology has facilitated the use of solid lubricants such as graphite, calcium fluoride, molybdenum disulphide, and boric acid as an alternative to cutting fluids in machining. Solid lubricant assisted machining is an environmental friendly clean technology for improving the surface quality of the machined work piece.
2017-07-10
Technical Paper
2017-28-1966
Praveen Kumar, Nareen Kinthala, Sri Viknesh Mohan, Harshad Bornare
Rapid prototyping is a revolutionizing technology extensively used in automotive, aerospace, medical, jewelry industries etc. Rapid Prototyping is an additive / subtractive layer manufacturing process, used to quickly fabricate a scale model from CAD data in just a matter of hours. In Automotive trims, rapid prototyping technology is a boon. It is used: -To simulate the "tooled up/production part" in terms of assembly, defined function and fit & finish. -To evaluate & capture early feedback from top management review in term of aesthetic, design, etc. -For early prediction and plan of action towards improvement for craftsmanship. -To reduce design iterations, product lifecycle time and cost. In this paper, we will discuss on technical aspects of how prototype models have been effectively put to use in order to validate Packaging, Assembly & Accessibility, Mechanism, Proof of concept, Functionality and Craftsmanship.
2017-07-10
Technical Paper
2017-28-1969
Senthil Ram N D, Thulasirajan Ganesan, 1Lt Praveen Chakrapani Rao
Magnesium alloy current being used for automotive sector and are being significantly used for manufacturing engine block as offering higher power to weight ratio to the vehicle. In this context, the magnesium alloy has been used in the replacement of aluminium alloy for the starter housing which in turn increase the power to weight ratio of the motor. Considering the operation condition of starter motor in the engine of the vehicles, the starter motor are being exposed to the harsh environment, where its system are being tested for Noise, Vibration and Harshness. In this paper, the magnesium alloy housing is used to study the vibration and noise developed in the starter motor and the same is compared with the noise and vibration of the motor when it being used with Aluminium alloy Housing. First, the vibration study is carried out for the housing part alone to capture the resonant frequency of the both housing alloy say, Aluminium and Magnesium.
2017-07-10
Technical Paper
2017-28-1972
ANIL P M, Cd Naiju
Direct Metal Deposition (DMD) is a rapid prototyping technique used to fabricate and repair metallic prototypes. It can be used in the production of complex geometries and unique parts. In functional automotive applications wear characteristics hold key importance. In the present study, an analysis on the influence of various parameters (coating thickness, load and temperature) on the wear characteristics of Direct Metal Deposited (DMD) Inconel 625 coating has been carried out using a Design of Experiments (DOE). ANOVA calculations were performed to find out which of these parameters showed significant influence on the wear properties. It was found that load was the most significant parameter influencing the wear characteristics .Similarly load was found to be most influencing parameter for co efficient of friction. The trend was found to follow when verified at 30 second, 3 minutes, 60 minutes and 120 minutes.
2017-07-10
Technical Paper
2017-28-1970
Sreeraj Kodoor
White etching crack (WEC) failure is distinct from classical rolling contact fatigue failure, frequently observed in bearings of electric power driven accessories of automobiles and wind turbine gearbox bearings etc. Release of atomic hydrogen from tribochemical reaction such as the lubricant failure and water contamination due to sever operating condition is believed to be one of accelerating factor of WECs & premature bearing failure. The cause of White etching area (WEA) formation associated WEC appearing 1-20% of L10 bearings life and premature failure is still under investigation. The method of creating WEC in laboratory condition is reported as a tedious and longer process for the root cause analysis. The paper would be a study of formation of WEA due to dynamic loading on Pin on disc tribometer. This paper, number of experiment was carried out using modified Pin on disc having dynamic load facility.
2017-07-10
Technical Paper
2017-28-1973
Sakthivel B, Sridhar R, Srinivasan B, J Suresh Kumar
Solenoids are type of inductive actuators extensively used in mobility industries as flow control valves. Now a day, the conventional mechanical actuators are replaced by solenoids, since the solenoids have high precision control and faster response within a controlled magnetic field. Solenoids are classified into two types based on the mode of operation. Solenoid is operated either in ON/OFF mode for switching applications or in Pulse Width Modulation (PWM) for high frequency applications. A solenoid consists of two critical parts, one is the reciprocating plunger and another is the static valve case. During higher number of repeated operations, the solenoid plunger hits the valve case and induces wear on the seating surface. The solenoids are also exposed to the corrosive environment in some applications.
2017-07-10
Technical Paper
2017-28-1975
ANIL P M, K Nantha Gopal, B. Ashok
The present study aims at investigating the friction and wear characteristics by blending zinc diakyldithio phosphates(ZDDP)with pongamia oil methyl ester as lubricant under various loading conditions and temperatures. Coefficient of friction and wear scar depth were determined using pongamia biodieselblended with 0.3%, 0.6% and 1 % ZDDP by concentration through high frequency reciprocating wear testing machine for 2 hrs duration. The reciprocating wear tests were performed on an engine liner-piston ring contact for various loads of 40N, 60N and 80 N for 2 hrs duration at temperatures of 100C, 125C 150C with 10 Hz oscillation frequency as per ASTM G181, 11. The addition of ZDDP with pongamia bio-lubricant showed marginal reduction in friction coefficient and wear scar depth under all loads and temperatures. Coefficient of friction was found to be higher in the initial stages due to running-in for all testing conditions.
Viewing 151 to 180 of 110083