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Technical Paper

Wall Heat Flux on Impinging Diesel Spray Flame: Effect of Hole Size and Rail Pressure under Similar Injection Rate Condition

2020-10-30
2020-32-2313
The fuel economy of recent small size DI diesel engines has become more and more efficient. However, heat loss is still one of the major factors contributing to a substantial amount of energy loss in engines. In order to a full understanding of the heat loss mechanism from combustion gas to cylinder wall, the effect of hole size and rail pressure under similar injection rate conditions on transient heat flux to the wall were investigated. Using a constant volume vessel with a fixed impingement wall, the study measured the surface heat flux of the wall at the locations of spray flame impingement using three thin-film thermocouple heat-flux sensors. The results showed that the characteristic of local heat flux and soot distribution was almost similar by controlling similar injection rate except for the small nozzle hole size with increasing injection pressure.
Technical Paper

Experimental Analysis on the Effects of Passive Prechambers on a Small 2-Stroke Low-Pressure Direct Injection (LPDI) Engine

2020-10-30
2020-32-2305
Two-stroke (2S) engines still play a key role in the global internal combustion engine (ICE) market when high power density, low production costs, and limited size and weight are required. However, they suffer from low efficiency and high levels of pollutant emissions, both linked to the short circuit of fuel and lubricating oil. Low- and high-pressure direct injection systems have proved to be effective in the reduction of fuel short circuiting, thus decreasing unburnt hydrocarbons and improving engine efficiency. However, the narrow time window available for fuel to be injected and homogenized with air, limited to few crank-angles, leads to insufficiently homogenized fuel-air mixtures and, as a consequence, to incomplete combustions. The use of prechambers can be a well-suited solution to avoid these issues.
Technical Paper

Investigations on NOx and Smoke Emissions Reduction Potential through Diesel-Water Emulsion and Water Fumigation in a Small Bore Diesel Engine

2020-10-30
2020-32-2312
In the present work, a relative comparison of addition of water to diesel through emulsion and fumigation methods is explored for reducing oxides of nitrogen (NOx) and smoke emissions in a production small bore diesel engine. The water to diesel ratio was kept the same in both the methods at a lower concentration of 3% by mass to avoid any adverse effects on the engine system components. The experiments were conducted at a rated engine speed of 1500 rpm under varying load conditions. A stable water-diesel emulsion was prepared using a combination of equal proportions (1:1 by volume) of Span 80 and Tween 80. The mixture of Span 80 in diesel and Tween 80 in water was homogenized using an IKA Ultra Turrax homogenizer with tip stator diameter 18mm at 5000 rpm for 2 minutes. The water-in-diesel emulsions thus formulated were kinetically stable and appeared translucent. No phase separation was observed on storage for approximately 105 days.
Technical Paper

Lubricating Oil Droplets from Piston Crown on Abnormal Combustion in Supercharged SI Engine

2020-10-30
2020-32-2302
In recent years, the supercharged spark ignition engine (SI engine) is spread out in the field of passenger vehicle. However, it has a problem of abnormal combustion which is called Low Speed Pre-ignition (LSPI). It is cleared gradually that the character of lubricating oil effects on LSPI behavior. The lubricating oil which has a tolerance for LSPI has been introduced already in the market nowadays. However, cause and mechanism of LSPI occurrence does not clear sufficiently. In previous conference SETC 2018, it was reported that the peculiar behavior of LSPI corresponded with behavior of lubricating oil from piston crown. This paper focuses on frequency of lubricating oil scattering from piston crown.
Technical Paper

Enclosure-In-Chamber Setup to Achieve Near-Zero Background Concentrations for Brake Emissions Testing

2020-10-05
2020-01-1634
Measuring brake emission is still a challenging non-standardized task. Extensive research is ongoing. Updates of work in progress are presented at SAE Brake Colloquium and PMP meetings. However, open items include how to achieve lower background concentration and how to design the brake enclosure. A low background concentration is essential as brake events are short and some emit in the range of reported background levels. Hence these emissions are difficult to distinguished from the background level. Even more critical, a high background concentration can result in a wrong particle number emissions value, either overestimated, background counted as emissions, or underestimated, background level subtracted, and low emission events no longer detected and counted. However, reducing the background level to less than 100 #/cm³ appeared to be quite challenging.
Technical Paper

A Generic Testbody for Low-Frequency Aeroacoustic Buffeting

2020-09-30
2020-01-1515
Raising demands towards lightweight design paired with a loss of originally predominant engine noise pose significant challenges for NVH engineers in the automotive industry. From an aeroacoustic point of view, low frequency buffeting ranks among the most frequently encountered issues. The phenomenon typically arises due to structural transmission of aerodynamic wall pressure fluctuations and/or, as indicated in this work, through rear vent excitation. A possible workflow to simulate structure-excited buffeting contains a strongly coupled vibro-acoustic model for structure and interior cavity excited by a spatial pressure distribution obtained from a CFD simulation. In the case of rear vent buffeting no validated workflow has been published yet. While approaches have been made to simulate the problem for a real-car geometry such attempts suffer from tremendous computation costs, meshing effort and lack of flexibility.
Technical Paper

Experimental Investigation on the Effects of Cooled Low Pressure EGR and Water Injection on Combustion of a Turbocharged GDI Engine

2020-09-27
2020-24-0003
This work focuses on the effects of cooled Low Pressure EGR and Water Injection observed by conducting experimental tests consisting mainly of Spark Advance sweeps at different cooled LP-EGR and WI rates. The implications on combustion and main engine performance indexes are then analysed and modelled with a control-oriented approach, showing that combustion duration and phase and exhaust gas temperature are the main affected parameters. Results show that cooled LP-EGR and WI have similar effects, being the associated combustion speed decrease the main cause of exhaust gas temperature reduction. Experimental data is used to identify control-oriented polynomial models able to capture the effects of LP-EGR and WI on both these aspects. The limitations of LP-EGR are also explored, identifying maximum compressor volumetric flow and combustion stability as the main ones.
Technical Paper

Performance Evaluation of Extended-Range Electric Vehicles equipped with Hydrogen-Fueled Rotary Engine

2020-09-27
2020-24-0011
The growing need for a sustainable worldwide mobility is leading towards a paradigm shift in the automotive industry. The increasingly restrictive regulations on vehicle emissions are indeed driving all of the world-leading road vehicles manufacturers to redesign the concept of transportation by developing new propulsion solutions. To this aim, a gradual electrification strategy is being adopted, and several hybrid electric solutions, such as extended-range electric vehicles with reciprocating engines or fuel cells, already represent a valid alternative to conventional vehicles powered by fossil fuels. Despite their appealing features, these hybrid propulsion systems present some drawbacks, mainly related to their complex architecture, causing high overall dimensions, weight and costs, which pose some limitation in their use for small-size vehicles.
Technical Paper

Turbulent jet ignition Effect on Exhaust Emission and Efficiency of a SI Small Engine Fuelled with Methane and Gasoline

2020-09-27
2020-24-0013
Pollutant emission of vehicle cars is nowadays a fundamental aspect to take into account. In the last decays, the company have been forced to study new solutions, such as alternative fuel and learn burn mixture strategy, to reduce the vehicle’s pollutants below the limits imposed by emission regulations. Pre-chamber ignition system presents potential reductions in emission levels and fuel consumption, operating with lean burn mixtures and alternative fuels. The aim of this work is to study the evolution of the plasma jets in a different in-cylinder conditions. The activity was carried out in a research optical small spark ignition (SI) engine equipped alternatively with standard ignition system and per-chamber. The engine runs at 2000 rpm at wide open throttle (WOT) in standard ignition condition and slightly turbocharged in prechamber condition in order to overcame the decrease of compression ratio. In this activity methane and gasoline were used.
Technical Paper

Correlation of Experimental Thermal Mapping and FEA Thermal Simulation for Cylinder Head for Diesel Engine Development.

2020-09-25
2020-28-0353
For upgrading/new engine development, the piston and cylinder head are the most exposed members due to amplified mechanical and thermal loadings. Mechanical loading is basically due to the combustion gas pressure in the combustion chamber and its scale can be judged in terms of peak cylinder pressure. Thermal loading is due to temperature by heat flux acting on the piston surface, cylinder liner and the cylinder head. The relative importance of the various loads applied on the head and cylinder block in operation are assessed and a method of predicting their influence on the structural integrity of the components described by doing actual test on engine test bench. So therefore, its very important to have thermal survey of the engine. The engine thermal survey test was primarily developed to measure the temperature in the head of the engine to determine if the temperatures that are measured are within the design guidelines for appropriate engine operation.
Technical Paper

Influence of Injection Parameters on performance and emission of DI Diesel Engine Fueled by 1,4-Dioxane Emulsified Fuel

2020-09-25
2020-28-0518
The pattern of utilizing the water/diesel emulsion fuels in engines has been given great importance due to its eco-friendly nature and minimal exhaustion of petroleum reserves. This investigation displays the impact of 1,4-dioxane emulsified fuel on performance and emissions at various operating pressures. 1,4-dioxane emulsified fuel (DWA10) was prepared with 10% 1,4-dioxane, 10% water, 0.2% surfactant and 79.8% diesel. To estimate the engine performance and emissions, the engine was operated with 180 bar, 200 bar and 220 bar operating pressures and the output was equated with diesel fuel operating on normal pressure of 200 bar. BTE of 1, 4-dioxane emulsified fuel at 220 bar was higher when compared with diesel fuel. CO, HC and BSEC were lower at 220 bar when compare with diesel fuel. However, NOx was found to increase for the higher operating pressure.
Technical Paper

Experimental Analysis of Injector Nozzle Coking on Multi-Cylinder Diesel Engine Considering Worst-Case Operating Conditions Including Engine Exhaust Brake

2020-09-25
2020-28-0332
Injector nozzle coking can severely limit engine performance by limiting the amount of fuel delivered to the combustion chamber and altering the spray pattern. Injector nozzle coking is also one of the most sensitive measures of diesel fuel quality. Formation of deposits within the holes of the injector nozzle or on the outside of the injector nozzle may have an adverse effect on overall system performance. There is no single factor that results in nozzle coking but can be classified in four major areas e.g. spray hole geometry, application duty cycle, nozzle localized temperature and the fuel quality. This paper provides a critical review of the current understanding of the main factors affecting the deposit formation. Engine was tested by motoring dynamometer using test cycle generated by Cummins Inc, as an attempt to try to simulate field conditions.
Technical Paper

Experimental and Numerical Investigation of Contact Pressure Existence in Sealing Structure

2020-09-25
2020-28-0343
Sealing is one of the important components in the automotive and aerospace industry. The primary function of the lip seal is to protect contamination and retaining the lubricant. This investigation relates to a study of contact pressure existence on sealing structure between there mating region. Sealing for steering intermediate shaft should sustain sliding motion between shaft and seal as well as protection of lubricant from contamination and retention. Contact pressure analysis of Steering intermediate shaft with hyper elastic rubber seal is done at static condition using ABAQUS. Experiments were also conducted to check contact pressure between seal and shaft by using Fuji-pressure film sensor. The result from CAE analysis was compared with experimental data with 75% of the correlation with respect to CAE. This analysis of contact pressure helps to support on giving enough interference between seal and shaft which satisfies the need of sealing for an intermediate shaft.
Technical Paper

Modular Design and Analyze of Air Intake Manifold for Formula Vehicle

2020-09-25
2020-28-0485
The SAE formula student car organization constrained a rule to place a restrictor of diameter 20mm in between the throttle body and the engine inlet. The restrictor is a component that reduces and regulates the mass flow of air into the engine inlet. For this, a venture nozzle will be used as a restrictor in a vehicle to decrease the air pressure and increase the velocity in the intake manifold. Our proposed work aims to minimize the pressure drop by changing the convergent and divergent angles in the restrictor. For this by using solidworks eight various combinations of models with convergent angle as 13, 15 degrees, and divergent angle as 5,7 degrees was designed and analyzed using CFD fluent in ansys work bench. In this, 13 degree as convergent and 5 degree as a divergent model was found to have laminar airflow throughout with optimum pressure drop. The plenum is a large duct that equalizes the pressure drop caused by the restrictor in order to improve the efficiency of the engine.
Technical Paper

Design and development of Plastic cylinder head cover with Integrated CCV in place of Aluminum Cylinder head cover .

2020-09-25
2020-28-0468
In Current landscape, automotive makers are targeting light weighting and Cost reduction as key areas to improve Energy efficiency and Total cost of ownership respectively. One such area which is becoming increasing popular is use of Thermoplastic in various Engine application. In presented approach, Cylinder head cover for Light duty Diesel engine has been converted from Aluminum to Thermoplastic, additionally Close crankcase ventilation system is integrated in Cover. Further, a novel sealing system is designed to take care of sealing performance issues possibly caused by design of cover. Finally developed components were verified and validated at Vehicle as well as Test bed level for its Durability and reliability. Newly integrated CCV system has also verified for its function. At the end Test results were compared and further actions proposed.
Technical Paper

Estimation of Heat Transfer Rate to Coolant from Combustion Chamber of Liquid Cooled IC Engine

2020-09-25
2020-28-0366
Heat transfer analysis in the combustion chamber of internal combustion engine is crucial to design the combustion chamber. Manufactures will always look for the durability, better engine performance and also on the material cost for designing the combustion chamber. This will be achieved by designing the efficient combustion chamber effectively. The purpose of this paper is to determine the Adiabatic Flame Temperature using stoichiometric equations and find the gas temperatures at different points in the ideal diesel cycle. These values are used in the existed heat transfer coefficient equations and estimate the heat transfer to the coolant through the cylinder wall using one dimensional heat equation. This theoretical value of heat transfer rate is compared with the experimental heat transfer rate of the three cylinder engine. The average error percentage of the theoretical and experimental values is less than the 15 %.
Technical Paper

Investigations on the Effect of Synchronizer Strut Detent Groove Profile on Static and Dynamic Gear Shift Quality of a Manual Transmission

2020-09-25
2020-28-0319
Automotive manufacturers are constantly working towards enhancing the driving experience of the customers. In this context, improving the static and dynamic gear shift quality plays a major role in ensuring a pleasant and comfortable driving experience. Moreover, the gear shift quality of any manual transmission is mainly defined by the design of the synchronizer system. The synchronizer sleeve strut detent groove profile plays a vital role in defining the performance of the synchronizer system by generating the minimum required pre-synchronization force. This force is important to move the outer synchronizer ring (blocker ring) to the required index position and to wipe-out the oil from the conical friction surfaces to build rapid high cone torque. Both these functional requirements are extremely critical to have a smooth and quick synchronization of the rotating parts under dynamic shift conditions.
Technical Paper

Modeling and Simulation of a Fighter Aircraft Cabin Temperature Control System Using AMESim

2020-09-25
2020-28-0497
Environmental Control System (ECS) of an aircraft is a complex system which operates classically in an air standard refrigeration cycle. ECS controls the temperature, pressure and flow of supply air to the cockpit, cabin or occupied compartments. The air cycle system of ECS takes engine bleed air as input. Parameters like bleed air pressure and temperature, mass flow, the external factors like ambient temperature, pressure, and aircraft attitude affect the performance of ECS to a large extent especially during transient. So, it is very important to consider the transient characteristics of these parameters in the design stage itself in order to ascertain the dynamic response of the system. This paper explains in detail the importance of transient input characteristics during the detailed design of ECS. A typical temperature control scheme for combat aircraft ECS has been studied and modeled in LMS AMESim.
Technical Paper

Ergonomic Study of Occupant Seating Using Near-Vertical Posture for Shared Mobility Applications

2020-09-25
2020-28-0519
Transportation system is at the brink of revolution and many new ways of mobility are arising in the market to ease the pressure on the established transportation infrastructure. Many companies and governments around the world are exploring innovative options in the space of shared mobility to reduce the overall carbon footprint. To expedite the adoption of shared mobility in India, it is necessary to make such options comfortable and cost-effective. One of the most effective way to make shared mobility options cost effective is to comfortably increase occupancy per vehicle footprint. This paper aims to evaluate a novel method of occupant seating to identify the maximum number of passengers a vehicle can accommodate without significant impact on occupant comfort. It is assumed that shared mobility options are used for a short duration of commute, and hence the comfort of the seat can be marginally compromised to increase the total number of occupants.
Standard

Aftermarket Wheels - Passenger Cars and Light Truck - Performance Requirements and Test Procedures

2020-09-23
WIP
J2530
This SAE Recommended Practice provides performance, sampling, and certifying requirements, test procedures, and marking requirements for aftermarket wheels intended for normal highway use on passenger cars, light trucks, and multipurpose passenger vehicles. For aftermarket wheels on trailers drawn by passenger cars, light trucks or multipurpose vehicles, see SAE J1204. These performance requirements apply only to wheels made of materials included in Table 1 and Table 2. New nomenclature and terms are added to clarify wheel constructions typically not used in OEM applications. The testing procedures and requirements are based on SAE standards listed in the references.
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