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Technical Paper

Lubricating Oil Droplets in Cylinder on Abnormal Combustion in Supercharged SI Engine

2018-10-30
2018-32-0008
The supercharged spark ignition engine has a problem of abnormal combustion at low speed and high load operating condition. This paper focuses on the sauce and mechanism of the abnormal combustion, namely, the behavior of lubricating oil droplets in cylinder, ring crevice, piston crown and ring gap. The experimental approach and the numerical analysis have been carried out. The two experimental approaches namely direct photography by high speed camera and measurement of scattering oil quantity at low speed condition have been tried. The photographs which is in engine operation show, 1st The oil droplets from ring crevice scatter every reciprocating motion and the diameter of oil droplets is between 0.10mm and 0.30mm. 2nd The oil droplets from piston crown has three steps as follows, firstly, the lubricating oil which reaches piston crown continues to accumulate, secondly, the accumulated lubricating oil scatters by the reciprocating motion.
Technical Paper

Effect of Fuel Injection Timing on the Mixture Preparation in a Small Gasoline Direct-Injection Engine

2018-10-30
2018-32-0014
Gasoline direct-injection (GDI) engines have evolved as a solution to meet the current demands of the automotive industry. Benefits of a GDI engine include good fuel economy, good transient response, and low cold start emissions. However, they suffer from problems, like combustion instability, misfire, and impingement of fuel on in-cylinder surfaces. Therefore, to highlight the influence of fuel injection timing on in-cylinder flow, turbulence, mixture distribution and wall impingement, a computational study is conducted on a small-bore GDI engine. Results showed that air motion inside the engine cylinder is influenced by direct-injection of fuel, with considerable variation in turbulent kinetic energy at the time of injection. Due to the charge cooling effect, mixture density and trapped mass were increased by about 10.8% and 9.5%, respectively.
Technical Paper

Performance Assessment of Fuel System for a Single Cylinder Engine using SI Turbulent Combustion Modeling and 3D CFD Simulation

2018-10-30
2018-32-0013
This paper demonstrates the use of engine 1D simulation and 3D CFD simulation in assessing the performance of the single cylinder engine. The main objective of the current work to develop fuel system for the engine in succession to improve the combustion quality, performance and emission of the engine. To achieve these tasks, firstly fuel supply system components were analyzed to investigate the combustion parametersthat influence the engine combustion quality. Secondly, precise flow phenomena in fuel supply system, which regulate the flow patterns and air fuel mixture formation in the intake port and the combustion chamber were principally analyzed using 3D CFD ANSYS Forte. The engine were premixed with propane fuel and the in cylinder combustion process was modeled using G-equation model. In the current investigation, SI Turbulent predictive combustion model is used in the GT power 1D model which is based on the eddy burn rate combustion model.
Technical Paper

Effects of Port-Injection Specifications on Air Fuel Ratio and Emission Behavior under Transient Operation

2018-10-30
2018-32-0012
In port injection, the influence of fuel adhesion on intake port wall caused by varying of injection location on exhaust A/F under the transient and the exhaust gas composition was evaluated. Meanwhile, the adhesion was observed to clarify the mechanism that governs these behaviors on the transition process.  When the engine speed was low and the throttle opening degree after rapid opening was low in the upstream injection, the exhaust A/F under and after transient operation was found to rich spike. Conversely, in the downstream injection, although lean spike did occur under transient operation, no rich spike was found under and after transient operation. Superposition of fuel adhesion to the intake port wall and liquid fuel film flow were observed under and after transient operation at low engine speed in upstream injection using intake port visualization.
Technical Paper

Experimental Study of Spark-Assisted Auto-Ignition Gasoline Engine with Octagonal Colliding Pulsed Supermulti-Jets and Asymmetric Double Piston Unit

2018-10-30
2018-32-0004
Much effort has been devoted to studies on auto-ignition engines of gasoline including homogeneous-charge combustion ignition engines over 30 years. The two key aims are lower exhaust energy loss due to high-compression ratio and less dissipation loss due to throttle-less device. However, the big problem underlying gasoline auto-ignition is knocking phenomenon leading to strong noise and vibration. In order to overcome this problem, we propose the principle of colliding pulsed supermulti-jets. In a prototype engine developed by us, octagonal pulsed supermulti-jets collide and compress the air around the center point of combustion chamber, which leads to a hot spot far from chamber walls. After those, the mechanical compression of an asymmetric double piston unit which moves with nearly sigmoidal mode is added, which brings auto-ignition of gasoline.
Technical Paper

CFD Analysis of a Port Fuel Injection IC Engine to Study Air-Fuel Mixture Preparation and its Impact on Hydrocarbon Emission and Mixture Homogeneity in Combustion Chamber

2018-10-30
2018-32-0005
At part load conditions, effective utilization of fuel is critical for drivability of an IC engine driven automobile, with minimum emissions and fuel consumption. It becomes cardinal to study the mixture preparation in engines to understand the Injection strategy that helps in achieving the prime objectives of lower emission and reliable operation. To add to the complexity of the problem being studied, the injection phenomenon is rapid, turbulent, multi-phase, two-way coupled (where the continuous phase affects the droplets and vice versa) and involves turbulence length scales and time scales, few orders of magnitude lower compared to the characteristic length in the turbulence integral scale. A methodology is developed in Star-CD and ES-ICE to simulate the mixture preparation in Port Fuel Injection (PFI) engines.
Technical Paper

Devolopment of a Riding Simulator for Motorcycles

2018-10-30
2018-32-0031
We developed the motorcycles based on RIDEOLOGY (Ride + Ideology) concept. In the past, the “Ride” was studied by a sensory evaluation with actual driving. However, the recent progress in numerical analysis, there have been developed driving simulators. It allows more qualitative measurement in a sensory evaluation. Therefore, we also developed a riding simulator specialized for motorcycles. In order to develop such riding simulator, there are some technical issues for motorcycles. First, we need to reproduce roll motion of motocycles. Compared to four-wheeled vehicles, motorcycles have a larger operating roll angle and higher center of rotation. Second, we need to reproduce vehicle control by rider’s changing body position. A rider controls vehicle’s lean by shifting his center of gravity. Therefore, it is necessary to construct a measurement system of rider’s body position. Third, we need to improve senses of speed and immersion.
Technical Paper

Artificial Neural Network Based Predictive Emission and Fuel Economy Simulation of Motorcycles

2018-10-30
2018-32-0030
As the number of different engine and vehicle concepts for powered-two wheelers is very high and will even rise with hybridization, the simulation of emissions and fuel consumption is indispensable for further development towards more environmental friendly mobility. In this work, an adaptive artificial neural network based predictive model for emission and fuel consumption simulation of motorcycles is presented. The model is developed in Matlab and Simulink and is integrated to a longitudinal vehicle dynamic simulation whereby it is possible to simulate various and not yet measured test cycles. Subsequently it is possible to predict real drive emissions and on-road fuel consumption by a minimum of previous measurement effort. The modelling approach is adaptive in terms of usability for different engine and exhaust gas treatment systems as the model does not require specific knowledge about technical vehicle parameters, which can be unknown due to manufacturers’ concealment.
Technical Paper

Modeling of Quasi-Steady State Heat Transfer Phenomena with the Consideration of Backflow Gas Effect at Intake Manifold of IC Engines and its Numerical Analyses on 1-D Engine Simulation

2018-10-30
2018-32-0029
As of early 21st century, automotive industry is genuinely involved with hybrid and electrical vehicles. However, it is safe to say that these new trends are considered to be available solely for developed countries. In a wider perspective, effect and importance of diesel engines still account an important role in the developing countries such as China, Indonesia and so forth. Thus, its performance and efficiency measures still play a crucial aspect both for economy and environment. In order to improve the thermal efficiency and performance of internal combustion engines, it is necessary to model the heat transfer phenomenon at the intake system and predict intake air mass flow rate into the engine cylinder. In the previous studies, the heat transfer phenomenon at the intake system was modeled as quasi-steady assumptions, based on Colburn analogy. Authors developed an empirical equation with the introduction of Graetz and Strouhal numbers, using a port model experimental setup.
Technical Paper

Enhancement of Thermal Fatigue Strength by the Addition of Calcium to Hypoeutectic Aluminum-Silicon Alloys

2018-10-30
2018-32-0027
The small engine is used under the severe environment of a large temperature change. Furthermore, it is required to enhance the thermal fatigue strength since the usage environment become more severe for satisfying emission regulations and the demands for high engine power. Hypoeutectic aluminum-silicon alloys are usually utilized for the material of the small engine due to their well-balanced properties such as density, castability and mechanical characteristics. In these alloys, the ductility, which strongly affects the thermal fatigue strength, differs depending on the morphology of the eutectic silicon. Herein, we controlled the morphology of the eutectic silicon by the addition of calcium and investigated castability and the mechanical properties. The sample with different calcium amount and cooling rate in cast was prepared. From cross-section images, it was revealed that the morphology of the eutectic silicon became fine with increasing the calcium amount and the cooling rate.
Technical Paper

A Study of Cycle-to-Cycle Flow Variations in a Small Spark-Ignition Engine at Low Throttle Opening

2018-10-30
2018-32-0035
Cycle-to-cycle flow variations significantly influence the combustion variations from one cycle to the next, particularly at low operating loads in small spark-ignition engines. Hence in the present work, cycle-to-cycle flow variations are analyzed at low throttle opening in a small spark-ignition engine using particle image velocimetry (PIV) technique. Experiments are conducted in an optically accessible single-cylinder port-fuel-injection engine (volume: 110 cm3) at 1200 rpm with throttle opening of 25%. Images are captured at different crank angle positions during both intake and compression strokes over a tumble measurement plane bisecting the intake and exhaust valves, and processed using cross-correlation method to obtain the instantaneous velocity fields considering 200 image pairs at each crank angle position considered.
Technical Paper

Static Stress and Thermal Analysis of Connecting Rod using FE-Analysis

2018-10-30
2018-32-0034
In series of automobile engine, in running conditions, different components of engine undergoes static and dynamic loadings. While one of the main component known as connecting rod is used to convert linear motion of the piston to reciprocating motion of the crankshaft. In this paper, a comparison study on connecting rods made up of 42CrMo4 Alloy Steel(Forged steel) and 7075-T6(SN) Aluminium Alloy is conducted to analyse the static and thermal stress, using the Finite Element Analysis (FEA). The main advantage of FEA is Virtual testing, it saves time and money. After measuring the dimension of connecting rod, the CAD model is developed in Solidworks software and imported to Solidworks Simulation software. Static stress analysis is done by fixing the crank end and the load is applied at the piston end of connecting rod and vice-versa. Maximum stress point and section prone to failure is found out by this analysis.
Technical Paper

Development of a Climate and Altitude Simulation Test Bench for Handheld Power Tools

2018-10-30
2018-32-0033
For evaluating the overall suitability of using innovative biofuels in handheld power tools such as chainsaws, trimmers and blowers, under any typical operating condition worldwide, a climate and altitude conditioning test bench was developed at the Institute of Energy Efficient Mobility (IEEM) of Karlsruhe University of Applied Sciences. The 6 m³ hermetically sealed and thermally insulated test chamber is large enough to fit the entire power tool. A two-stage refrigeration system with intake air drying and resistance heating allows for realistic temperature conditions to be set in the test chamber, ranging from arctic cold to tropical heat (-20 to 45 °C). Altitudes up to 3,000 m above sea level can be simulated using a throttle valve at the inlet of the chamber and a pressure-controlled rotary piston blower positioned downstream the test chamber outlet.
Technical Paper

Development of Coaxial Thin Film Temperature Sensor with Improved Measurement Accuracy Based on Principle of Thermoelectromotive Force

2018-10-30
2018-32-0032
In recent years, improvement of fuel consumption and thermal efficiency is strongly required in the internal combustion engine to promote environmental. It is important to clarify the mechanism and reduce of cooling loss, however it is very difficult to measure cooling loss (heat transfer coefficient) from the working gas to combustion chamber wall. Measuring experimentally heat flux from chamber surface to coolant is one of evaluation methods of the cooling losses in the combustion chamber and has been widely used for R&D process in IC engines. Although this method has capability to measure detail of cooling process instantaneously and accurately including local phenomena, but it is necessary to improve the S/N ratio and responsiveness and durability.
Technical Paper

Developing Efficient Motorcycles Oils

2018-10-30
2018-32-0021
Motorcycle OEMs faced with stringent global fuel economy and emission regulations (such as Euro-5 & BS-VI) are being forced to develop new hardware and emissions control technologies to remain compliant. Motorcycle lubricating oils have become an enabling technology for development of smaller, more efficient engines operating in higher power density regimes. OEMs have therefore become reliant on lubricants to not only provide enhanced durability under more extreme operating conditions, but to also provide fuel economy benefits through reduced frictional losses. Unlike passenger car oils that only lubricate the engine, motorcycle oils must lubricate both the engine and protect the drive train. These additional requirements place greater performance demands versus a conventional crankcase lubricant. The drive train includes highly loaded gears that are exposed to extreme pressures, in turn requiring higher levels of oil film strength and anti-wear system durability.
Technical Paper

Effects of In-cylinder Flow and Stratified Mixture on HCCI Combustion in High Load

2018-10-30
2018-32-0016
The purpose of this paper is to find a way to extend the high load limit of homogeneous charge compression ignition (HCCI) combustion. This paper presents the effect of in-cylinder flow and stratified mixture on HCCI combustion by experiments and three-dimensional computer fluid dynamics coupled with a detailed chemical reaction calculation. The first study was conducted using a rapid compression and expansion machine equipped with a plate to create in-cylinder turbulent flow and with a control unit of in-cylinder wall temperature to create in-cylinder temperature distribution. The study assesses the effect of the turbulent flow and the temperature distribution on HCCI combustion.In the second study, the numerical simulation of HCCI combustion was conducted using large eddy simulation coupled with a detailed chemical reaction calculation. The study analyzes the interaction between in-cylinder turbulent flow and mixture distribution and HCCI combustion.
Technical Paper

Development of Joint Sheet Gasket with Reduced Amount of Aramid Fibers

2018-10-30
2018-32-0026
Gasket made of joint sheet is widely used for mating surfaces of an engine and a transmission. Ahead of the law enforcement of banning of asbestos usage, Honda had already started to apply non-asbestos gasket using aramid fibers as the substitute material for asbestos all over the world. However, aramid fiber is very expensive while the sealing performance of a joint sheet largely depends on the added amount of aramid fibers. Therefore, when it is adopted, the resulting cost increase becomes an issue. Accordingly, we designed a material aiming at the cost reduction while maintaining the required reliabilities for a joint sheet in real applications mainly by reducing the amount of aramid fibers. According to the required characteristics for a joint sheet, the constituent materials of the middle layer were optimized by combining glass fibers with coarse-grained silica as a reinforcement substance into highly fibrillated aramid fibers as the base material.
Technical Paper

The Effect of Organic Friction Modifiers on Fully Formulated Motorcycle Engine Oils

2018-10-30
2018-32-0024
Most high-performance motorcycles use a multiplate, lubricated (“wet”) clutch pack. The main reasons for the lubrication are; cooling, and to protect the steel and friction plates from excessive wear. In such a motorcycle a single common oil sump is usually used to lubricate the engine, clutch and transmission. From a lubricant design point of view the ideal case would be to have individual fluids that are specifically designed for each task, as is the case in the majority of passenger cars. However, in most cases the extra size and weight that would be added by having separate oil sumps rather than one common oil sump is undesirable and would impact the ride and fuel economy. A motorcycle engine oil (MCO) must therefore perform well in several, seemingly contradictory, environments. This makes the choice of friction modifier (FM) more complex than it would be for a passenger car engine oil (PCEO).
Technical Paper

A Development of Measurement System for Piston Ring Sliding Surface Pressure

2018-10-30
2018-32-0022
The piston rings, the engine sliding parts, are required to further contribute on mechanical loss reduction in order to improve fuel economy. However, many cases of the abnormal combustion due to the oil upward flow, as well as the increase in oil consumption are been reported. Engine Lubricating oil consumption causes particulate matter, a negative effect on engine after treatment devices, and an increase in users running cost. Furthermore, a negative effect on combustion is reported recently. Therefore, elucidation of the mechanism of those phenomena is still an urgent task. It is widely known that the cylinder bore shape during the actual operation, and the distribution of the sliding face pressure in between the piston ring and the cylinder bore largely influence the oil flow via the sliding face of the piston ring. However, there are many unclear points about the conformability of the piston ring to the cylinder bore and the behavior of the lubricating oil around the piston ring.
Technical Paper

Definition of Test Conditions for High Voltage Aerospace Systems Using the IAGOS Atmospheric Dataset

2018-10-30
2018-01-1931
Aerospace electrical systems are continuing to increase their voltage levels to meet the on-board power demands of more-electric aircrafts (MEAs) where hydraulic and pneumatic systems are replaced with electrical equivalents. Higher power demands are leading to the use of higher voltages and as such it is essential to explore the behaviour of the insulation system in the aerospace environment. This degradation takes place in situations where equipment can be exposed to an aerospace environment consisting of operating temperatures up to 250 °C or as low as - 50 °C, varying air pressure, humidity and ozone. Understanding the impact of these variables on the ageing of high voltage insulation systems is crucial in predicting lifetime over the service life of an aircraft. This paper describes the results derived from an analysis of data within the In-service Aircraft for a Global Observing System (IAGOS) database. This database includes 47,000 flight profiles.
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