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As part of efforts to address climate change and improve energy security, researchers have improved the thermal efficiency of engines by expanding the lean combustion limit. To further expand the lean combustion limit, the authors focused not only on engine technology but the chemical reactivity of various fuel molecules. Furan and anisole were among the fuel molecules selected, based on the idea that promising candidates should enhance the flame propagation speed and have good knocking resistance. Engine testing showed that the lean limit can be expanded by using fuels with the right molecular structures, resulting in higher thermal efficiency.

Numerical modeling of engine combustion products requires detailed chemistry and therefore large computational resources and time. This becomes a constraint when engine optimization at system level is desired. In this paper, a 1D modeling approach is proposed for fast computation to predict emission level at various engine running conditions. A new chemical solver within 1D framework is developed along with suitable reduced chemical mechanism. The reduced reaction scheme is validated against detailed chemistry on 0D and 1D reactors. It is confirmed that the new fast 1D solver achieves more than 100X speed improvement. Now larger mechanisms can be used for better accuracy with reasonable turnaround time. This methodology allows virtual engine emission map generation, with a refined emission map completed within 12 hours of computational time.

Exhaust gas recirculation (EGR) can be used to mitigate knock in SI engines. However, experiments have shown that the effectiveness of various EGR constituents to suppress knock varies with fuel type and compression ratio (CR). To understand some of the underlying mechanisms by which fuel composition, octane sensitivity (S), and CR affect the knock-mitigation effectiveness of EGR constituents, the current paper presents results from a chemical-kinetics modeling study. The numerical study was conducted with CHEMKIN, imposing experimentally acquired pressure traces on a closed reactor model. Simulated conditions include combinations of three RON-98 (Research Octane Number) fuels with two octane sensitivities and distinctive compositions, three EGR diluents, and two CRs (12:1 and 10:1). The experimental results point to the important role of thermal stratification in the end-gas to smooth peak heat-release rate (HRR) and prevent acoustic noise.

In the automobile industry, interest in the prevention of global warming has always been high. The development of eco cars (HV, EV etc.), aimed at reducing CO2 emissions during operation, has been progressing. In the announcement of its "Toyota Environmental Challenge 2050", Toyota declared its commitment to creating a future in which people, cars, and nature coexist in harmony. In this declaration, Toyota committed to reducing CO2 emissions not only during operation but also over the entire life cycle of vehicles, and to using resources effectively based on a 4 R’s approach (refuse, reduce, reuse, and recycle). Although eco cars decrease CO2 emissions during operation, most of them increase CO2 emissions during manufacturing. For example, the rare-earths (Nd, Dy etc.) used in the magnets of driving motors are extracted through processes that produce a significant amount of CO2 emissions.

A highly anti-corrosive organic-inorganic hybrid paint for automotive steel parts has been developed. The inorganic component included in the paint is silicon dioxide (SiO2), which has the capability to passivate zinc. By application of the paint on a trivalent chromatetreated zinc-plated steel sheet or a trivalent chromate-treated zinc-nickel-plated steel sheet, high anti-corrosion protection can be provided to steel materials. Particularly in the case of application over a zinc-nickel-plated steel sheet, 0 mm corrosion depth after a cyclic corrosion test (CCT) of 450 cycles was demonstrated.

The dissolution and exfoliation of chromium plating specific to Russia was studied. Investigation and analysis of organic compounds in Russian soil revealed contents of highly concentrated fulvic acid. Additionally, it was found that fulvic acid, together with CaCl2 (a deicing agent), causes chromium plating corrosion. The fulvic acid generates a compound that prevents reformation of a passivation film and deteriorates the sacrificial corrosion effectiveness of nickel.

Port fuel injection (PFI) injector and direct fuel injection (DI) injector clogging from deposits caused by poor fuel quality, is a concern in emerging countries. Then DI injector deposits are sometimes cleaned by injector cleaners in such situation. However deposit cleaners for PFI injectors have not been developed, because of the lack of research of PFI injector deposits. Through chemical analysis, this study showed them to be water-soluble deposits. Subsequently success was achieved in developing a new gasoline injector cleaner applicable to injector deposits in both types of injectors, through optimization of a surface active agent.

In this report, adhesion mechanism between epoxy resin and primer and between primer and Ni platting in Hybrid vehicle (HV) was investigated. Adhesion forces are thought to be a combination of mechanical bond forces (such as anchor effect), chemical bond forces and physical bond forces (such as hydrogen bonding and Van der Waals force). Currently there is insufficient understanding of the adhesion mechanism. In particular, the extent to which the three bond forces contribute to adhesion strength. So the adhesion mechanism of polyimide primers was analyzed using a number of different methods, including transmission electron microscope (TEM) and atomic force microscope (AFM) observation, to determine the contributions of the three bonding forces. Molecular simulation was also used to investigate the relationship between adhesion strength and the molecular structure of the primer.

Weight reduction for a fuel cell vehicle (FCV) is important to contribute a long driving range. One approach to reduce vehicle weight involves using a carbon fiber reinforced plastic (CFRP) which has a high specific strength and stiffness. However, a conventional thermoset CFRP requires a long chemical reaction time and it is not easy to introduce into mass production vehicles. In this study, a new compression-moldable thermoplastic CFRP material for mass production body structural parts was developed and applied to the stack frame of the Toyota Mirai.

Current and future engine technologies and fuels are mutually dependent. The increased use of alternative fuels has been linked to deterioration in performance of injectors, fuel filters and engines as a result of insoluble deposit formation. The present work aimed to study the impact of Diesel/biodiesel blends formulation (biodiesel feedstock and content) and temperature on the oxidation stability based on total acid number (TAN). The biofuels used in the fuel matrix were: rapeseed, soy and palm methyl esters (RME, SME and PME respectively). The Diesel/biodiesel blends were made with 0%v/v, 5%v/v, 10% v/v and 20%v/v of biodiesel blended with additive-free new Diesel. The oxidation stability of Diesel/biodiesel blends was to evaluate during 6 months fuels storage, under 20°C and 40°C, and fuels severe oxidation into a reactor vessel to better understand the parameters leading to fuel oxidation on-board.

The details of Di-Air, a new NOx reduction system using continuous short pulse injections of hydrocarbons (HC) in front of a NOx storage and reduction (NSR) catalyst, have already been reported. This paper describes further studies into the deNOx mechanism, mainly from the standpoint of the contribution of HC and intermediates. In the process of a preliminary survey regarding HC oxidation behavior at the moment of injection, it was found that HC have unique advantages as a reductant. The addition of HC lead to the reduction or metallization of platinum group metals (PGM) while keeping the overall gas atmosphere in a lean state due to adsorbed HC. This causes local O₂ inhibition and generates reductive intermediate species such as R-NCO. Therefore, the specific benefits of HC were analyzed from the viewpoints of 1) the impact on the PGM state, 2) the characterization of intermediate species, and 3) Di-Air performance compared to other reductants.

To evaluate the influence of FAME, which has poor oxidation stability, on engine oil performance, an engine test was conducted under large volumes of fuel dilution by post-injection. The test showed that detergent consumption and polymerization of FAME were accelerated in engine oil, causing a severe deterioration in piston cleanliness and sludge protection performance of engine oil.

Phosphor thermometry was used during fuel injection in an optical engine with the glass piston of reentrant type. SiO2 coated phosphor particle was used for the gas-phase temperature measurements, which gave much less background signal. The measurements were performed in motored mode, in combustion mode with injection of n-heptane and in non-combustion mode with injection of iso-octane. In the beginning of injection period, the mean temperature of each injection cases was lower than that of the motored case, and temperature of iso-octane injection cases was even lower than that of n-heptane injection cases. This indicates, even if vaporization effect seemed to be the same at both injection cases, the effect of temperature decrease changed due to the chemical reaction effect for the n-heptane cases. Chemical reaction seems to be initiated outside of the fuel liquid spray and the position was moving towards the fuel rich area as the time proceeds.

Transmission electron microscope (TEM) is a powerful tool for studying catalyst materials at nano-size and/or atomic level. Conventional TEM usually needs to be observed at room temperature in high vacuum conditions. A gaseous atmosphere and high temperature condition may change the properties of catalyst materials. Recently we developed an in situ observation system in TEM for observing the oxidation and reduction under a gas atmosphere at high temperature. Using the new in situ observation system in TEM, the morphological changes of the nano particle and support were observed in the heated gaseous atmosphere at atomic level in real time.

NO2 sources of roadside atmosphere at Matsubarabashi monitoring station in Tokyo were investigated analytically. The result showed that contribution of urban background is dominant from November to February and NO oxidation with O3 has large contribution from April to September. NO2 air quality standard will be achieved by reducing vehicle NOx emission to post-new long-term regulation level. The analytical method was verified by using our developed simulation system, which consists of micro traffic flow analyzer and CFD-based, unsteady-state diffusion with chemical reaction solver.

Due to regulations for even lower levels of pollutants in exhaust gas, development of advanced combustion techniques and increasingly efficient catalysts has become more crucial than ever. One of the essential technologies to achieve this goal is an advanced measurement method, which can detect the characteristics of exhaust gas, such as temperature and chemical compositions, in real-time to clarify their reaction mechanisms. A direct and fast response (1ms) measurement technique was developed based on diode laser absorption spectroscopy and applied to practical engine exhaust measurement to prove the validity of this technology for various applications such as clarification of engine start phenomena and improvement of EGR controls.

The effects of intake dilution with various dilution gases including nitrogen, argon, and carbon dioxide on low temperature diesel combustion were investigated in a naturally aspirated DI diesel engine to understand the mechanism of the simultaneous reductions in smoke and NOx with ultra-high EGR. NOx almost completely disappears with the intake oxygen concentration diluted below 16% regardless of the kind of dilution gas. Smoke emissions decrease with increased heat capacity of the charged gas due to promotion of mixture homogeneity with longer ignition delays. Intake dilution with the 36% CO2 + 64% Ar mixture which has a similar specific heat capacity as N2 shows lower smoke emissions than with N2. Chemical kinetics analysis shows that carbon dioxide may help to reduce NOx and soot by lowering the reaction temperature as well as by changing the concentrations of some radicals or/and species related to soot and NOx formation.

Trivalent chromate coating is replacing the conventional hexavalent chromate coating applied on zinc plating. Zinc plating uses one of three types of plating baths (zincate, cyanide and chloride) according to the characteristics required of subject parts. It has been recognized that trivalent chromate coating provides different corrosion resistance depending on the type of zinc plating bath used. Zinc plating with chromate coating were analyzed to clarify the cause of the corrosion resistance variation with the type of zinc plating bath. It has been revealed that the chromate coating thickness and the condition of top SiO2 layer vary with the type of zinc plating bath, resulting in corrosion resistance variation.

In order to achieve good adhesive properties, typical decorative plastic plating technology uses a chromic acid process that creates an anchor effect. Due to environmental concerns with hexavalent chromium, there is a need to find alternative processes. Pretreatment using highly concentrated ozonized water was investigated as a novel approach to achieving this goal. In the conventional chromic acid process, strong adhesion between plating membranes is achieved by roughing the ABS (acrylonitrile-butadiene-styrene) resin surface by approximately 1 um. On the other hand, the highly concentrated ozonized water process achieves good adhesion with a smooth resin by changing the resin from ABS to ASA (acrylate-styrene-acrylonitrile). It was discovered that the difference in this strength of adhesion was the difference in resin surface strength (existence of deterioration or otherwise).

In recent years, alternative sources of fuel are receiving a lot of attention in the automotive industry. Fuels derived from an agricultural feedstock are an attractive option. Bio-fuels based on vegetable oils offer the advantage being a sustainable, annually renewable source of automobile fuel. One of key issues in using vegetable oil based fuels is its oxidation stability. Since diesel fuels from fossil oil have good oxidation stability, automobile companies have not considered fuel degradation when developing diesel engines and vehicles as compared with gasoline engines. This paper presents the results of oxidation stability testing on bio-fuels. Oxidation stability was determined using three test methods, ASTM D525, EN14112 and ASTM D2274. The effects of storage condition, bio-fuel composition and antioxidants on the degradation of bio-fuels were all investigated. ASTM D525 is an effective test method to determine the effects of storage condition on bio-fuels stability.