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Gasoline-related factors that affect low-speed pre-ignition (LSPI) include the distillation properties of gasoline, manganese (Mn), ethanol, diesel fuel, detergent for aftermarket, and iron (Fe). The combined effect of Mn with ethanol or high calcium engine oil (high-Ca oil) has not been sufficiently clarified. Therefore, appropriate countermeasures for LSPI have not yet been implemented. To clarify the effect of the gasoline properties and additives on LSPI, engine tests were conducted using gasoline with different “PM Index” values, an indicator of distillation properties, different concentrations of Mn, ethanol, diesel fuel, detergent, Fe, and high-Ca oil. The results showed that the LSPI frequency tended to increase with the PM Index, Mn up to 60 ppm, diesel fuel up to 2 vol.%, and detergent up to three times the standard amount.

Controllability is defined in ISO 26262 as a driver’s ability to avoid a specified harm caused by a malfunction of electrical and electronic systems installed in road vehicles. According to Annex C of Part 12 of ISO 26262, simulation is one of the techniques that the Controllability Classification Panel (CCP) can use to evaluate comprehensively the controllability class (C class) of motorcycles. With outputs of (i) an index for the success of harm avoidance and (ii) the magnitude of the rider’s compensatory control action required to avoid harm, the simulation is useful for evaluating the C class of the degrees of malfunction that cannot be implemented in practice for the sake of the test rider’s safety. To aim at supplying data that the CCP can use to judge the C class, we try to estimate the vehicle behavior and a rider’s compensatory control actions following a malfunction using vehicle dynamics simulations.

The SAE J300 classification was expanded to 0W-12 and 0W-8 viscosity grades in 2015, and lower viscosity engine oils have been studied in the industry. ILSAC GF-6B that will be introduced in 2020 will specify a 0W-16 requirement, but 0W-12 and 0W-8 grades are not considered. Because engine oil equal to or higher than the 0W-20 grade is recommended for almost all engines globally, suitable engine tests for 0W-12 and 0W-8 do not exist. Therefore, the Japan Automobile Manufacturers Association, Petroleum Association of Japan and Society of Automotive Engineers of Japan decided to establish new 0W-12 and 0W-8 low viscosity engine oil specifications. It is referred to as JASO GLV-1, and together with a new fuel economy engine test procedure, these engine oils for better fuel economy will be put on the Japanese market in 2019. Motoring friction torque tests are widely used to ascertain the friction reduction effect of fuel-economy engine oils.

This study employed a diesel particulate generator (DPG), with an installed engine oil injector for soot and ash accumulation in a diesel particulate filter (DPF). Ash was generated by engine oil injection into the diesel burner flame. The amount of soot accumulation per loading varied from 0.5 g/L to 8 g/L while ash accumulation amount per loading was maintained at 0.5 g/L. Initially, ash accumulation distribution in the DPF was visualized using X-ray computed tomography (CT). It was revealed that the form of ash accumulation changed depending on the amount of soot accumulation before active regeneration, i.e., a large amount of soot accumulation resulted in plug ash, whereas a small amount of soot accumulation resulted in wall ash. To clarify ash accumulation mechanisms, soot and ash transport behavior in DPF during active regeneration process was directly observed using a high-speed camera through an optically accessible D-shaped cut DPF covered with a quartz glass plate.

This work investigated the mechanism of oil dilution by post injection to remove accumulated particulate matter on the diesel particulate filter of diesel engines. We developed a model to simulate post injection spray under low ambient gas pressure conditions. The model can predict the quantity of fuel mass adhered on the cylinder wall. The adhered fuel enters oil sump through the piston ring and cause oil dilution. The fuel in diluted oil evaporates during normal engine operations. We focus on the mechanism of fuel evaporation from diluted oil. The effects of engine speed and oil temperature on the evaporation were investigated. The results showed that the fuel evaporation rate increases with increasing engine speed and oil temperature. Furthermore, we developed an empirical model to predict the fuel evaporation rate of diluted oil through regression analysis with measured data.

To meet the strict emission regulations for diesel engines, an advanced processing device such as a Urea-SCR (selective catalytic reduction) system is used to reduce NOx emissions. The Real Driving Emissions (RDE) test, which is implemented in the European Union, will expand the range of conditions under which the engine has to operate [1], which will lead to the construction of a Urea-SCR system capable of reducing NOx emissions at lower and higher temperature conditions, and at higher space velocity conditions than existing systems. Simulations are useful in improving the performance of the urea-SCR system. However, it is necessary to construct a reliable NOx reduction model to use for system design, which covers the expanded engine operation conditions. In the urea-SCR system, the mechanism of ammonia (NH3) formation from injected aqueous urea solution is not clear. Thus, it is important to clarify this mechanism to improve the NOx reduction model.

In the urea SCR system, urea solution is injected by injector installed in the front stage of the SCR catalyst, and NOx can be purified on the SCR catalyst by using NH3 generated by the chemical reaction of urea. NH3 is produced by thermolysis of urea and hydrolysis of isocyanic acid after evaporation of water in the urea solution. But, biuret and cyanuric acid which may cause deposit are sometimes generated by the chemical reactions without generating NH3. Spray behavior and chemical reaction of urea solution injected into the tail-pipe are complicated. The purpose of this study is to reveal the spray behavior and NH3 generation process in the tail-pipe, and to construct the model capable of predicting those accurately. In this report, the impingement spray behavior is clarified by scattered light method in high temperature flow field. Liquid film adhering to the wall and deposit generated after evaporation of water from the liquid film are photographed by the digital camera.

Diesel Particulate Filter (DPF) is a very effective aftertreatment device to limit particulate emissions from diesel engines. As the amount of soot collected in the DPF increases, the pressure loss increases. Therefore, DPF regeneration needs to be performed. Injected fuel into the exhaust line upstream of the Diesel Oxidation Catalyst (DOC), hydrocarbons are oxidized on the DOC, which increases the exhaust gas temperature at the DPF inlet. It is also necessary that the injected fuel is completely vaporized before entering the DOC, and uniformly mixed with the exhaust gases in order to make the DOC work efficiency. However, ensuring complete evaporation and an optimum mixture distribution in the exhaust line are challenging. Therefore, it is important that the fuel spray feature is grasped to perform DPF regeneration effectively. The purpose of this study is the constructing a simulation model.

A methodology for simulating effect of international variations in fuel compositions on spray combustion is proposed. The methodology is validated with spray combustion experiments with real fuels from three different countries. The compositions of those fuels were analyzed through GC×GC and H-NMR. It was found that ignition delay times, flame region and flame luminosity were significantly affected by the compositional variations. For the simulation, an evaporation surrogate consisting of twenty two species, covering basic molecular types and a wide range of carbon numbers, is developed. Each species in the evaporation surrogate is then virtually converted to a reaction surrogate consisting of n-hexadecane, methylcyclohexane and 1,2,4-trimethyl benzene so that combustion reactions can be calculated with a published kinetic model. The virtual species conversion (VSC) is made so as to take over combustion-related properties of each species of evaporation surrogates.

This study proposes a method for presenting maneuver request information of accelerator pedal to a driver via the accelerator pedal itself. By applying periodic force like vibration on an accelerator pedal, information is transferred to the driver without displacing the accelerator pedal. In this study, the authors focus on a saw-tooth wave as the periodic force. When the saw-tooth-waved force is applied on the accelerator pedal, a human driver feels as if the accelerator pedal is knocked by someone periodically. In addition, information about the quantity of requested maneuver can be transferred by the amplitude of the saw-tooth wave. Based on these facts, the saw-tooth wave is modified and optimized empirically with ten human drivers so that the information of direction is transferred most reliably. In addition, the relationship between the amplitude of the saw-tooth wave and requested quantity of the pedal maneuver that the drivers feel is formulated.

The localized fire test provided in the Global Technical Regulation for Hydrogen Fuel Cell Vehicles gives two separate test methods: the ‘generic installation test - Method 1′ and the ‘specific vehicle installation test - Method 2′. Vehicle manufacturers are required to apply either of the two methods. Focused on Method 2, the present study was conducted to determine the characteristics and validity of Method 2. Test results under identical burner flame temperature conditions and the effects of cylinder protection covers made of different materials were compared between Method 1 and Method 2.

Electric vehicles have become more popular and may be involved in fires due to accidents. However, characteristics of fires in electric vehicles are not yet fully understood. The electrolytic solution of lithium-battery vehicles is inflammable, so combustion characteristics and gases generated may differ from those of gasoline cars. Therefore, we conducted fire tests on lithium-ion battery vehicles and gasoline vehicles and investigated the differences in combustion characteristics and gases generated. The fire tests revealed some differences in combustion characteristics. For example, in lithium-ion battery vehicles, the battery temperature remained high after combustion of the body. However, there was almost no difference in the maximum CO concentration measured 0.5 to 1 m above the roof and 1 m from the side of the body. Furthermore, HF was not detected in either type of vehicle when measured at the same positions as for CO.

Appropriate emergency response information is required for first responder before hydrogen fuel cell vehicles will become widespread. This paper investigates experimentally the hydrogen dispersion in the vicinity of a vehicle which accidentally releases hydrogen horizontally with a single volumetric flow of 2000 NL/min in the under-floor section while varying cross and frontal wind effects. This hydrogen flow rate represents normally a full throttle power condition. Forced wind was about maximum 2 m/s. The results indicated that the windward side of the vehicle was safe but that there were chiefly two areas posing risks of fire by hydrogen ignition. One was the leeward side of the vehicle's underbody where a larger region of flammable hydrogen dispersion existed in light wind than in windless conditions. The other was the area around the hydrogen leakage point where most of the leaked hydrogen remained undiffused in an environment with a wind of no stronger than 2 m/s.

In Biodiesel Fuel Research Working Group(WG) of Japan Auto-Oil Program(JATOP), some impacts of high biodiesel blends have been investigated from the viewpoints of fuel properties, stability, emissions, exhaust aftertreatment systems, cold driveability, mixing in engine oils, durability/reliability and so on. This report is designed to determine how high biodiesel blends affect oil quality through testing on 2005 regulations engines with DPFs. When blends of 10-20% rapeseed methyl ester (RME) with diesel fuel are employed with 10W-30 engine oil, the oil change interval is reduced to about a half due to a drop in oil pressure. The oil pressure drop occurs because of the reduced kinematic viscosity of engine oil, which resulting from dilution of poorly evaporated RME with engine oil and its accumulation, however, leading to increased wear of piston top rings and cylinder liners.

The demands of application of dual-axis chassis dynamometers (4WD-CHDY) have increased recently due to the improvement of performance of 4WD-CHDY and an increase in the number of 4WD vehicles which are difficult to convert to 2WD. However, there are few evaluations of any differences between fuel economy and exhaust emission levels in the case of 2WD-CHDY with conversion from 4WD to 2WD (2WD-mode) and 4WD-CHDY without conversion to 2WD (4WD-mode). Fuel economy and exhaust emission tests of 4WD vehicle equipped with a typical 4WD mechanism were performed to investigate any differences between the case of the 2WD-mode and the 4WD-mode. In these tests, we measured ‘work at wheel’ (wheel-work) using wheel torque meters. A comparison of the 2WD-mode and the 4WD-mode reveals a difference of fuel economy (2WD-mode is 1.5% better than that of 4WD-mode) and wheel-work (2WD-mode is 3.9% less than that of 4WD-mode). However, there are almost no differences of exhaust emission levels.

The study of 10% ethanol blended gasoline (E10 gasoline) utilization has been conducted in the Japan Auto-Oil Program (JATOP). In order to clarify the impact of E10 gasoline on vehicle performances, exhaust emissions, evaporative emissions, driveability and material compatibility have been investigated by using domestic gasoline vehicles including mini motor vehicles which are particular to Japan. The test results reveal that E10 gasoline has no impact on exhaust emissions, engine startup time and acceleration period under the hot start condition, but a slight deterioration is observed in some test cases under the cold start condition using E10 gasolines with 50% distillation temperature (T50) level set to the upper limit of Japanese Industrial Standards (JIS) K 2202. Regarding evaporative emissions, the tested vehicles shows no remarkable increase in the hot soak loss (HSL), diurnal breathing loss (DBL) and running loss (RL) testing with E10 gasolines.

It is becoming more and more necessary to achieve a sustainable low-carbon society by mobility not depending on oil. Electric vehicles are appropriate for such a society, but expensive battery cost and long charging time prohibit the promotion of EVs. One of the solutions is minimizing battery usage by ultra-low fuel efficiency, so we developed an ultrahigh-efficient electric commuter concept car “C-ta”, which requires as small a battery as possible. We assumed that drivers would use the car as a second car for short-distance daily use, such as commuting, shopping, transportation of family, etc. In order to improve fuel efficiency, we mainly considered an ultra-light weight body and chassis, to which CFRP (carbon fiber reinforced plastic) greatly contributes, ultra-low rolling resistance tires, and highly accurate vehicle control technology with four in-wheel motors.

Hydrogen concentration during combustion in a confined space with a ceiling was investigated. The results indicated that steady-state hydrogen concentration was highest at the ceiling surface for all hydrogen flow rates. When hydrogen concentration was 10-20%, weak flame propagation occurred at the ceiling surface, with the most easily burnable spots being dented areas such as seams, pores and creases on the ceiling surface. The unstable and limited nature of flame propagation at the ceiling surface was attributed to the relationship between temperature and hydrogen concentration in a confined space.

The SAE Fuel Cell Vehicle (FCV) Safety Working Group has been addressing FCV safety for over 11 years. In the past couple of years, significant attention has been directed toward a revision to the standard for vehicular hydrogen systems, SAE J2579(1). In addition to streamlining test methodologies for verification of Compressed Hydrogen Storage Systems (CHSSs) as discussed last year,(2) the working group has been considering the effect of vehicle fires, with the major focus on a small or localized fire that could damage the container in the CHSS and allow a burst before the Pressure Relief Device (PRD) can activate and safely vent the compressed hydrogen stored from the container.

This paper proposes a new mixing-controlled, low temperature combustion (LTC) approach for high-speed direct injection (HSDI) diesel engines. The purpose of this approach is to avoid the excessively high pressure-rise rate (PRR) of premixed, kinetics-controlled LTC and to enable the low nitrogen oxides (NOx) combustion to operate over the wide speed and load range of the engine. To address the soot/noise trade-off at high load LTC operating conditions, the pressure modulated multiple-injection coupled with swirl control was applied. This injection strategy enables the injection of high pressure (HP) main spray into the local high temperature region of the already burning low pressure (LP) pilot spray injected from the neighboring injection hole. By employing this injection strategy, the equivalence ratio (φ) distribution of mixture is drastically varied during main combustion processes.