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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

A Simulation Study Assessing the Viability of Shifting the Location of Peak In-Cylinder Pressure in Motored Experiments

2020-09-27
2020-24-0009
Some hybrid powertrains utilize an engine to benefit from the power density of the liquid fuel while the electric machine; for transient needs, for very low loads and where legislation prohibits any gaseous and particulate emissions. Consequently, the operating drive cycle of an engine also shifted from its conventional, broad range of speed and load to a narrower operating range of high thermal efficiency. This requires a drastic departure from conventional engine architecture, meaning that analytical models used to predict the behaviour of the engines early in the design cycle are no longer always applicable. Friction models are an example of sub-models which struggle with previously unexplored engine architectures. The pressurized motored method has proven to be a simple experimental setup which allows a robust FMEP determination against which engine friction simulation can be fine-tuned.
Technical Paper

INNOVATIVE ELECTRIC OIL PUMPS FOR DIFFERENT AUTOMOTIVE APPLICATIONS

2020-09-27
2020-24-0022
The current request of electrical components is associated to the uncertainty of the market strategy and to the risk of technological recursion during development, due to the high level of innovation. For this reason, the products, which are under development, have to cover the worst-case use scenarios and be modular as much as possible, to be adapted on an evolving context. We developed an innovative electric oil pump, with BLDC motor and integrated electronic for automotive applications. Even if this concept is already consolidated, we upgraded it in order to be able to cover typical automotive temperature ranges and by targeting high power density and reduced packaging, perfect for the new powertrains layouts.
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. In the present work, the static and dynamic shift quality of a 300 Nm manual transmission is analyzed with different synchronizer sleeve strut detent profiles. The synchronizer sleeve strut detent groove profile play 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.
Technical Paper

Experimental and Numerical Investigation of Contact Pressure Existance in Sealing Structure

2020-09-25
2020-28-0343
Sealing is one of the important components in automotive and aerospace industry. The primary function of lip seal is to protect contamination and retaining the lubricant. This investigation relates to study of contact pressure existence on dynamic sealing. Sealing for steering intermediate shaft requires 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 as well as sliding 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. This analysis of contact pressure helps to support enough interference between seal and shaft with satisfies the need of sealing as well as sliding in intermediate shaft.
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

Design and analyse of air intake in manifold student formula vehicle

2020-09-25
2020-28-0485
The SAE organization constrained a rule to place a restrictor of diameter 20mm in between the throttle body and the engine inlet . The restrictor is an component which reduces and regulates the mass flow of air into the engine inlet. For this a venture nozzle will be used as a restrictor in vehicle to decrease the air pressure and increase the velocity in the intake manifold . The aim of our proposed work is to minimize the pressure drop by changing the convergent and divergent angles in the restrictor. For this by using solidworks sixteen various models with convergent angle as 11,13,15,17 degrees and divergent angle as 3,5,7,9 degrees was designed and analysed using CFD fluent in ansys work bench. In this 13 degree as convergent and 5 degree as divergent model was found to have laminar air flow through out with optimum pressure drop. The plenum is a large duct which equalise the pressure drop caused by restrictor in order to improve the efficiency of engine.
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

Effects of Internal Geometry on High-Pressure Gasoline Sprays using High-Speed Imaging

2020-09-15
2020-01-2111
High-pressure gasoline injection can be utilized for improved combustion efficiency and lower engine-out emissions. The objective of this study was to quantify the effects of injector geometry on high-pressure gasoline transient spray development in a constant volume chamber. Five injector nozzles were studied with controlled internal flow features including differences in inlet rounding, conicity, and outlet diameter. Effects of fuel injection pressure and chamber density on the spray characteristics were investigated. Reference grade gasoline was injected at pressures of 300, 600, 900, 1200, and 1500 bar. The chamber density was varied with pressurized nitrogen at 1, 5, 10 and 20 bar at a constant temperature of 298 K, corresponding to ambient densities of 1.13, 5.65, 11.31, and 22.61 kg/m3. The spray development was recorded using diffuse backlit shadowgraph and high-speed imaging methods.
Technical Paper

Soot Load Monitoring in Gasoline Particulate Filter Applications with RF - Sensors

2020-09-15
2020-01-2171
With the start of Euro 6d regulations, gasoline particulate filters (GPF) have become standard equipment in European vehicles with gasoline-direct-injection engines. GPFs will also be broadly applied to meet the upcoming China 6 regulations. An existing challenge with GPFs is accurate soot load detection to manage the pressure loss across the exhaust system and to protect the GPFs from soot overload, which could potentially cause damage as result of uncontrolled soot oxidations. Systems with the GPF located in the under-floor position have a higher potential risk of soot overload due to lower temperatures, which can result in higher soot accumulation rates. The accuracy of existing soot estimation methods such as evaluation of the pressure drop of the soot-loaded GPF or model-based balancing of soot accumulation versus soot oxidation rates are sensitive to transient operating condition of a vehicle.
Technical Paper

Numerical Investigation on GDI Spray Under High Injection Pressure Up to 100MPa

2020-09-15
2020-01-2108
In recent years the increase of injection pressure gasoline fuel is a way to improve thermal efficiency and lower engine-out emissions in GDI homogenous combustion concept. The challenge of controlling particulate formation as well in mass and number concentrations imposed by emissions regulations can be pursued improving the mixture preparation process and avoiding mixture inhomogeneities with ultra-high injection pressure values up to 100MPa. The increase of the fuel injection pressure meets the demand for increased injector static flow, while simultaneously improving the spray atomization and mixing characteristics that provide improvement of the combustion performance of GDI homogeneous systems. Few studies quantify the effects of high injection pressure on transient gasoline spray evolution.
Technical Paper

Problems of Reducing Friction Losses of a Piston-Ring-Cylinder Configuration in a Combustion Piston Engine with an Increased Isochoric Pressure Gain

2020-09-15
2020-01-2227
Currently, there is a tendency to increase the mean workable pressure in internal com-bustion engines, to reduce their total capacity and the number of cylinders in a balanced man-ner, depending on the vehicle's class and weight in order to improve the thermal and mechani-cal efficiency of the engine. An increased engine torque at a slight angular velocity results in an increase in the mean value of the unit pressure distribution of the piston rings, especially the upper sealing ring in the initial period of the expansion stroke, which limits the slip effect affect-ing the ability to form an oil film. The essence of validity of increasing the isochoric degree of pressure gain is the use of vehicles at low speeds with a high torque. Such selection of parame-ters ensures good motion dynamics at low fuel consumption.
Technical Paper

GDI Sprays with up to 200 MPa Fuel Pressure and Comparison of Diesel-Like and Gasoline-Like Injector Designs

2020-09-15
2020-01-2104
To address stricter emission limits, GDI develops to increased fuel pressure. Current gasoline injectors are already operating at a pressure of up to 35 MPa and an elevation is still promising lower particle emissions and increased efficiency. There have been only few studies of GDI sprays at pressures >50 MPa. Contrary, in Diesel engines injection pressure up to 250 MPa are common. GDI and Diesel injector designs limit liquid penetration in different ways. With elevated fuel pressure the question arises which design concept limits the penetration depth more effectively. To investigate the properties of high pressure sprays, a GDI injector (100 MPa max. fuel pressure) and an injector with Diesel-like design are compared. High speed Shadowgraphy and Schlieren technique are used to gather information of liquid and vapor phase propagation. With Phase-Doppler-Anemometry the diameter and the velocity of droplets in the sprays are recorded.
Technical Paper

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

2020-09-15
2020-01-2148
Laminar burning velocity of bio-diesel air mixture has been studied in a spherical bomb, using the pressure – time records. I also varied initial pressure, temperature to cover a range from 1.013bar-4bar and 400k-500k 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. For each experimental run, instantaneous burning velocities were calculated in the range of 1.5P0 to 0.75 P max and the laminar burning velocity values between the burned mass fraction of 0.2 and 0.3 were averaged to get burning velocity value for a particular experimental run.
Technical Paper

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

2020-09-15
2020-01-2152
In this work, the ignition delay of bio-diesel and its blends with diesel at atmospheric pressure and temperature 850 0 C has been studied. The results are compared to those for diesel oil. Specifically, the suspended fuel droplet was inserted into a hot combustion chamber containing atmospheric air at temperatures which varied from 625 0- 850 0 C. The fuel droplet was suspended on the fine silica fiber wire of diameter 550 micron which was mounted on rod and inserted in the hot combustion chamber at atmospheric condition. The ignition of the droplet was observed by optical circuit (optical sensor) and recorded by CRO and the ignition time was determined. 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.
Technical Paper

Effects of Ignition Control on Combustion Process Non-Repeatability in an Aircraft Radial Piston Engine

2020-09-15
2020-01-2044
The ignition method significantly affects the combustion process in piston aircraft engines. This paper presents the results of bench tests of two variants of the radial piston aircraft engine: equipped with a standard magneto system and an electronic dual ignition system. The engine was tested in steady states for operating points defined by rotational speed and load. Their values corresponded to a load ranging from 50% of nominal power to take-off power. The ignition advance angle was constant for the engine equipped with ignition magnetos, while for the second engine variant it was determined by the developed algorithm introduced to the electronic ignition system control unit. The analysis of the combustion process was based on pressure measurements in one cylinder.
Technical Paper

High-Speed Imaging of Main-Chamber Combustion of a Narrow Throat Pre-Chamber under Lean Conditions

2020-09-15
2020-01-2081
Pre-chamber combustion (PCC) allows an extension on the lean limit of an internal combustion engines (ICE), which makes a great potential to reduce the emissions of criteria pollutants. Compared to a conventional spark-ignition engine, this combustion mode also provides lower NOx emissions and shorter combustion durations that lead to a higher indicated efficiency and lower specific fuel consumption. In this present work, a narrow throat pre-chamber was tested, which has a particular nozzle area distribution of 2 rings of 6 nozzle holes. The narrow throat pre-chamber was tested in a modified heavy-duty for optical visualization. Methane was used as fuel for both fuel lines, and the combustion tested regimes belonged to lean conditions. Two test matrices were devised at two different intake pressures in order to examine the effect of pressure.
Technical Paper

A Machine Learning Modeling Approach for High Pressure Direct Injection Dual Fuel Compressed Natural Gas Engines

2020-09-15
2020-01-2017
The emissions and efficiency of modern internal combustion engines need to be improved to reduce their environmental impact. Many strategies to address this (e.g., alternative fuels, exhaust gas aftertreatment, novel injection systems, etc.) require engine calibrations be modified, which requires significant experimental data. A new approach to modeling and data collection is needed to expedite the development of these new technologies and reduce their upfront cost. This work evaluates a Bayesian Optimization, Gaussian Process Regression and Artificial Neural Network based strategy for the efficient development of machine learning models intended for optimization and calibration of engines. The objective of this technique is to generate an engine performance model suitable for optimization with a significantly reduced data set of 174 data points.
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