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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

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

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

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

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.
Technical Paper

Influence of Injection Parameters on Performance and Emission of DI Diesel Engine Fuelled by 1,4-Dioxane Emulsified Fuel

2020-09-25
2020-28-0518
The pattern of utilizing the water/diesel emulsion fuels in engines had been given great importance due to its ecological and 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 (DWSD10) 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 compare with diesel fuel. CO, HC and BSEC were lower at 220 bar on par with diesel fuel. However, NOx was increases for the higher operating pressure. Overall, except NOx, at higher injection pressure (@220 bar) the 1,4-dioxane emulsified fuel outperforms the diesel fuel in terms of emission and performance.
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.
Standard

Heat Treatment of Parts in a Vacuum

2020-09-22
CURRENT
AMS2769D
This specification establishes the requirements and procedures for heat treating parts in vacuum/partial pressure and shall be used as a supplementary document to primary heat treating specifications as applicable.
Standard

Aircraft Wheel Inflation Valves Incorporating an Inflation Pressure Gauge

2020-09-16
WIP
ARP5543A
This specification covers the recommended design, construction, performance and testing requirements for aircraft wheel inflation valves incorporating an inflation pressure gauge which are mounted on the aircraft wheel. These valve/gauge assemblies should be appropriate for use on all aircraft types supported by tubeless tire/wheel assemblies.
Technical Paper

Study on the Pre-Chamber Fueling Ratio Effect on the Main Chamber Combustion Using Simultaneous PLIF and OH* Chemiluminescence Imaging

2020-09-15
2020-01-2024
Pre-chamber combustion (PCC) enables leaner air-fuel ratio operation by improving its ignitability and extending flammability limit, and consequently, offers better thermal efficiency than conventional spark ignition operation. The geometry and fuel concentration of the pre-chamber (PC) is one of the major parameters that affect overall performance. To understand the dynamics of the PCC in practical engine conditions, this study focused on (i) correlation of the events in the main chamber (MC) with the measured in-cylinder pressure traces and, (ii) the effect of fuel concentration on the MC combustion characteristics using laser diagnostics. We performed simultaneous acetone planar laser-induced fluorescence (PLIF) from the side, and OH* chemiluminescence imaging from the bottom in a heavy-duty optical engine. Two different PC Fueling Ratios (PCFR, the ratio of PC fuel to the total fuel), 7%, and 13%, were investigated.
Technical Paper

Experimental Assessment of the Impact of Fuel Properties on the Rail Pressure Fluctuations

2020-09-15
2020-01-2122
Injection pressure oscillations are proven to determine considerable deviations from the expected mass flow rate, leading to the jet velocities non-uniformity, which in turn implies the uneven spatial distribution of A/F ratio. Furthermore, once the injector is triggered, these oscillations might lead the rail pressure to experience a decreasing stage, to the detriment of spray penetration length, radial propagation and jet break-up timing. This has urged the research community to develop models predicting injection-induced pressure fluctuations within the rail. Additionally, several devices have been designed to minimize and eliminate such fluctuations. However, despite the wide literature dealing with the injection-induced pressure oscillations, many aspects remain still unclear. Moreover, the compulsory compliance with environmental regulations has shifted focus onto alternative fuels, which represent a promising pathway for sustainable vehicle mobility.
Technical Paper

Evaluation of Geometry-Dependent Spray Hole Individual Mass Flow Rates of Multi-Hole High-Pressure GDI-Injectors Utilizing a Novel Measurement Setup

2020-09-15
2020-01-2123
In order to optimize spray layouts of commonly used high-pressure injectors for gasoline direct injection (GDI) engines featuring multi-hole valve seats, a detailed understanding of the cause-effect relation between inner spray hole geometries and inner flow conditions, initializing the process of internal mixture formation, is needed. Therefore, a novel measurement setup, capable of determining spray hole individual mass flow rates, is introduced and discussed. To prove its feasibility, a 2-hole configuration is chosen. The injected fuel quantities are separated mechanically and guided to separate pressure tight measurement chambers. Each measurement chamber allows for time resolved mass flow rate measurements based on the HDA measurement principle (German: “Hydraulisches Druck-Anstiegsverfahren”).
Technical Paper

Determination of Kinematic Parameters for the Combustion of Jatropha Based Bio-Diesel

2020-09-15
2020-01-2148
Laminar burning velocity is a fundamental measurement describing how a flame propagates into quiescent unburned mixture ahead of the flame at a specified pressure and temperature. Laminar burning velocity of bio-diesel air mixture has been studied in a spherical bomb, using the pressure - time records. Initial pressure, temperature is varied to cover a range from 1 bar - 4 bar and 443K-523K respectively. The range of measurements covered the equivalence ratio from 0.8 to 1.2. Pressure-time records have been used to calculate the flame velocity, burned gas fraction, flame position etc., using a simplified, two zone thermodynamic model, assuming equilibrium composition and homogenous mixture for the burned gases. It is also assumed frozen composition and isentropic compression for the unburned mixture.
Technical Paper

Experimental Investigation of Ignition Delay of Bio-Diesel and Its Blends

2020-09-15
2020-01-2152
In this work, the ignitjion delay of bio-diesel and its blends with diesel at atmospheric pressure and temperature 8500C has been studied. The results are compared to those for diesel oil. Specifically, the suspended fuel droplet is inserted into a hot combustion chamber containing atmospheric air at temperatures which varied from 6250 - 8500C. The fuel droplet is suspended on the fine silica fibre wire of diameter 550 micron. It is mounted on rod and inserted in the hot combustion chamber at atmospheric condition. The ignition of the droplet is observed by optical circuit (optical sensor) and recorded by CRO. The ignition time is determined for calculating ignition delay. The results are plotted on the ignition delay ln(t) - 1/Temperature, K-1 coordinates to obtain the value of Activation Energy, EA. It has been found that the value of Activation Energy, EA is 44.3kJ for bio-diesel and 53.4kJ for diesel.
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