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Increasingly restrictive emission standards and CO2 targets drive the need for innovative engine architectures that satisfy the design constraints in terms of performance, emissions and drivability. Downsizing is one major trend for Spark-Ignition (SI) engines. For downsized SI engines, the increased boost levels and compression ratios may lead to a higher propensity of abnormal combustions. Thus increased levels of Exhaust Gas Recirculation (EGR) are used in order to limit the appearance of knock and super-knock. The drawback of high EGR rates is the increased tendency for Cycle-to-Cycle Variations (CCV) it engenders. A possible way to reduce CCV could be the generation of an increased in-cylinder turbulence to accelerate the combustion process. To manage all these aspects, 1D simulators are increasingly used. Accordingly, adapted modeling approaches must be developed to deal with all the relevant physics impacting combustion and pollutant emissions formation.

Fibrous material is widely used in automotive silencers in order to dissipate high frequency noise components and attenuate the high-level pressure wave propagating from the cylinders. Its accurate acoustic model is in demand with a highly increased reliance on acoustic simulation of automotive exhaust systems. In this investigation, several empirical formulae and fibrous models in one-dimensional CFD codes are reviewed and their acoustic characteristics, e.g. propagation constants and characteristic impedance, are compared. Also, they are applied to some typical automotive silencers in order to check the validity of each model. It was found that some default fibrous models in commercial one-dimensional CFD codes were not satisfying. For the improvement of those results, DOE (Design of Experiment) and a commercial optimization tool were applied to find the optimal input values in their fibrous model.

In this study, the re-starting characteristics of a motorcycle engine with idle-stop were investigated. Generally when turning off the engine, there is; or when restarting engine, the air-fuel mixture will become rich to cause the incomplete combustion. When the restarting period is shortened, the aforementioned phenomena would be improved. The aim of this study was to shorten the engine re-starting time during start-up. In the initial stage of the study, the gear ratio of the starter was changed, and the parameters of the engine speed and cylinder pressure were measured and analyzed. The results showed that supplying the additional fuel injection duration of 3 milliseconds into the combustion chamber before the engine was stopped would give the quicker restarting characteristics.

Foaming of lubricating oil during operation of any automotive mechanism is undesirable. To control this problem, anti-foaming additives are often part of the formulated oil. However, during use, the oil contacts the gasketing material used to seal the mechanism and may extract pro-foamants in sufficient quantity to overwhelm the anti-foamant additive. Recognition of this problem has led to several different in-house tests of oil/gasket compatibility seemingly giving divergent information and technical direction concerning correction of foam-inducing factors of both the oil and gasket. It seemed appropriate to investigate and quantify the relative importance of several of the presumed influences on oil/gasket interaction. To do this, a relatively simple test simulating oil/gasket contact in the operating mechanism has been developed around an air foam-bath and applied in a series of Taguchi matrix studies to determine the influential factors.

The combustion timing, work output and in-cylinder peak pressure for HCCI engines often converge to a stable equilibrium point, which implies that the HCCI combustion may have a self-stabilization feature. It is thought that this behavior is due to the competing residual-induced heating and dilution of the reactant gas. As one of the most important features of HCCI combustion, the self-stabilization behavior can give great guidance to people for designing controller for HCCI engine control. The self-stabilization features of HCCI combustion had been observed by many researchers and mentioned in some publications. However, there is no report to experimentally analyze this phenomenon individually. Due to the fuel injection normally ending during the NVO process and the spark plug is turned off for HCCI engines, there is no direct control approach between the Intake Valve Close (IVC) and the start of combustion.

Little research has been done on spray characteristics of 2,5-dimethylfuran (DMF), since the breakthrough in its production method as an alternative fuel candidate. In this paper, the spray characteristics of pure fuels (DMF, Isooctane) and DMF-Isooctane blends under different ambient pressures (1 bar, 3 bar and 7 bar) and injection pressures (50 bar, 100 bar and 150 bar) were studied using Phase Doppler Particle Analyzer (PDPA) and high speed imaging. Droplet velocity, size distribution, spray angle and penetration of sprays were examined. Based on the results, DMF had larger SMD and penetration length than isooctane. The surface tension of fuel strongly influenced spray characteristics. Increasing the surface tension by 26 % resulted in 12 % increase in SMD. Higher ambient pressure increased the drag force, but SMD was not influenced by the increased drag force. However, the increased ambient pressure reduced the injection velocity and We number resulting in higher SMD.

1 Generally some Chinese gasoline has long-term storage from few months to four years, and will be exposed to light in the transportation and distribution processes. So whether the antiknock additive Methylcyclopentadienyl Manganese Tricarbonyl (MMT) can be applied to gasoline is in question. The Fuel Storage Management Administration (FSMA) in China wants to make clear the stability of MMT in gasoline and its effect on the gasoline quality when exposed to sunlight. In this study the base gasoline was prepared using typical gasoline blending stocks in China. The 28-week darkroom storage experiments at 43 °C were performed to study the storage stability of MMT in gasoline and its influence on the gasoline properties. The sunlight exposure experiments were conducted to assess the photolysis characters of MMT and its impact on the properties of gasoline with the establishment of kinetic equations.

The introduction of stricter emission legislation and the demand of increased power for small two-wheelers lead to an increase of technical requirements. Especially the introduction of liquid-cooling over air-cooling allows the introduction of higher compression ratios, which improves power output as well as thermodynamic efficiencies and thereby fuel consumption. But an increase in compression ratio also introduces further challenges during transient behavior especially close to idling. In order to keep the two-wheeler specific responsiveness of the vehicle, the overall rotational inertia of the engine must be kept low. But the combination of low inertia and high compression ratio can lead to a stalling of the engine if the throttle is opened and closed very quickly in idle operation. The fast opening and closing of the throttle is called a throttle blip.

The introduction of new emission legislation and the demand of increased power for small two-wheelers lead to an increase of technical requirements. Especially for single cylinder engines with high compression ratio the transient behavior close to idling is challenging. The demand for two-wheeler specific responsiveness of the vehicle requires low overall rotational inertia as well as small intake manifold volumes. The combination with high compression ratio can lead to a stalling of the engine if the throttle opens and closes very quickly in idle operation. The fast opening and closing of the throttle is called a throttle blip. Fast, in this context, means that the blipping event can occur in one to two working cycles. Previous work was focused on the development of a procedure to apply reproducible blipping events to a vehicle in order to derive a deeper physical understanding of the stalling events.

The present reserves of liquid petroleum fuels indicate that it may not last for longer period. It has become necessary to search for an alternative fuel which can be used in the present engines. Coal, having large reserves and being abundantly available in India comes to be the first choice. This paper considers steps necessary for making ability of normal engines to accept coal fuels. The program for development of the coal fueled engine has a initial stage of feasibility validation. Some specific areas were selected for investigations of this stage. The investigations were proceeded in sequence of study of the literature and systems, solid fuels and preparation specially suitable for conditions in India. The fuel feed system was developed for the above engine. The initial assessment of combustion process of the coal fuels in the engine was performed with the help of analytical and experimental method.

Use of water diesel emulsions in diesel engines has resulted in drastic reductions in NOx and smoke levels, while the thermal efficiency is also improved. The objective of this work is to evaluate the effects of using water diesel emulsion as the pilot fuel in a dual fuel engine with LPG as the primary fuel. Tests were conducted on a single cylinder constant speed DI diesel engine. An emulsion with a water to diesel ratio of 0.4:1 was used. Performance, HC, CO, NOx, smoke emissions and combustion parameters were obtained and compared with the case where pure diesel was used as the pilot fuel. At high loads, the brake thermal efficiency with the emulsion as the pilot fuel was better than that with diesel. NOx levels were drastically reduced. The already low smoke levels were reduced further with the emulsion. There was an adverse effect on HC and CO emissions. The maximum rate of pressure rise and peak pressure were also higher with the emulsion.

A transient behavior investigation of a hybrid hand-held tool is carried out on near real load conditions, through a hybrid experimental and simulative study. As this study focuses on handheld tools with a varied or transient load operation like chainsaws and brush cutters, a use of a blower tool as a test-carrier and a throttle body implementation on its blower air pipe adds a controllable braking mechanism. This allows for driving varied load cycles without the need of a testbench. Experimental investigation takes place at both start-up, shut-down and load conditions and for different drive control and commutation modes of electric motor. The controller characterization and parameter selection are done. After the load cycles are driven on the test-carrier, the characterizing data are transferred to the MATLAB and Simulink simulation model to correct and calibrate its transient behavior.

Ethanol direct injection plus gasoline port injection (EDI+GPI) is a new technology to make the use of ethanol fuel more effective and efficient in spark ignition engines. It takes the advantages of ethanol fuel, such as its greater latent heat of vaporization than that of gasoline fuel, to enhance the charge cooling effect and consequently to increase the compression ratio and improve the engine thermal efficiency. Experimental investigation has shown improvement in the performance of a single cylinder spark ignition engine equipped with EDI+GPI. It was inferred that the charge cooling enhanced by EDI played an important role. To investigate it, a CFD model has been developed for the experimentally tested engine. The Eulerian-Lagrangian approach and Discrete Droplet Model were used to model the evolution of the fuel sprays. The model was verified by comparing the numerical and experimental results of cylinder pressure during the intake and compression strokes.

The techniques of device manufacturing control and screen testing employed today allows an escape rate of latent defects which makes probability of mission success of a manned interplanetary mission questionable. The increased system complexity and mission duration underscore the need to establish maximum integrated circuit reliability and a test sequence to prove that it exists. This paper describes a technique of utilizing life distributions of Integrated circuits obtained under high-stress testing to establish reliability screening criteria. Discussed are the basic factors controlling observable lot behavior, what can be learned from them, and how they dictate a test approach. Analyzed are the typical life expectancy distributions obtainable from today's devices; what the probable escape rates of defective devices are; how they may be made observable; and finally, how the expected life of accepted devices may be altered by stress screening.

Ethanol has been used either as an alternative fuel or in blends with gasoline in spark ignition (SI) engines for many years. However, the existing method of using ethanol fuel by blending gasoline and ethanol fuel does not fully exploit the ethanol fuel's potential in improving engine thermal efficiency and reducing pollutant emissions. The dual-fuel injection strategy, ethanol direct injection plus gasoline port injection (EDI+GPI), offers a potentially new way to make the best use of ethanol fuel. In this paper the potential of EDI+GPI is investigated based on experiments conducted on a single cylinder SI research engine equipped with EDI+GPI. The leveraging effect of EDI+GPI on engine performance was investigated at different ethanol/gasoline energy ratios (EERs) and speeds. Then further investigation to the leveraging effect enhanced by ethanol injection timing and spark timing was performed. Experimental results showed that the IMEP increased with the increase of EER.

In recent years the number of vehicles equipped with millimeter wave radar has been increasing due to the popularization of driving assistance systems such as adaptive cruise control (ACC) and forward vehicle collision warning (FCW) systems. Consequently, high performance millimeter wave radar must be developed to support even more advanced driving assistance systems. The investigation described in this paper confirms that it is possible to use high range resolution radar to recognize the width of a target. In tests, a simulated radar signal was transmitted and received by a millimeter waveband network analyzer using a 1.6 meter-wide aluminum foil board as the target. When the range resolution was low, only one point of reflection from the board could be detected. However, when the range resolution was improved, then multiple points of reflection from the target could be detected.

This paper presents a numerical methodology for studying the effect of boiling on the structural behavior of high-performance internal combustion engines. Boiling occurs when the portion of engine coolant in contact with hot walls reaches high temperatures and vapor bubbles form. While incipient vaporization of the coolant can promote additional cooling, excessive vapor can act as an insulator and lead to potentially dangerous high temperatures in the engine. Boiling is typically analyzed using Computational Fluid Dynamic Analyses, which are usually computationally intensive. In this study, the authors propose a Finite Element methodology that combines semi-empirical formulations, less demanding than Computational Fluid Dynamic models, with thermal Finite Element simulations to detect and manage boiling. Two different empirical formulations for boiling were employed, proposed by Garro and Chen respectively, and their results were compared.

A wide range of engineering domains, such as aeronautical, automobiles, and marine, rely on the use of Metal Matrix Composites (MMC). Due to the excellent properties, such as hardness and strength, Aluminum base MMC are generally adopted in various uses. Due to the increasing number of reinforcement materials being added to the MMC, its properties are expected to improve. In this exploratory analysis, an effort was given to develop a new aluminium-based MMC. The analysis of the machinability of the composite was also performed. The process of creating a new MMC using a stir casting technique was carried out. It resulted in a better and more reinforced composite than its base materials. The reinforcement materials were fabricated using different weight combinations and process parameters, such as the temperature and duration required to stir. Due to the improved properties of the composite, the traditional machining method is not feasible for machining of these materials.

In an attempt to abate soot emissions, diesel fuel for a direct-injection, single-cylinder diesel engine was step-by-step replaced with natural gas. The gas was introduced into the intake system. As a result of this, soot emissions were decidedly improved and maximum power was increased. As an undesirable secondary effect, especially at small loads, there was an unacceptable increase in brake specific gas-diesel fuel consumption and an increase in emission of harmful gaseous exhaust components. Exhaust gas recirculation and throttling were investigated as possible countermeasures. Both are capable of reducing the emission of poisonous gaseous exhaust components at high gas rates, without essentially increasing soot emission. Also, higher part-load consumption could be reduced by these countermeasures.

Databus systems in motor vehicles allow communication between electronic control devices. Among the factors of particular interest for the development of a bus system are electromagnetic compatibility (EMC) and, especially for realtime applications, performance. This paper deals with EMC measurements conducted on a bus system for multiplex applications which is currently undergoing testing at Daimler-Benz. The second half of the paper presents a comparison of performance of ABUS and CAN data-bus protocols, these being well suited for controlling time-critical operations, in respect of data rate, bus access time, bit error probability and message priority.