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In this study, two kinds of control methods for the transient operation of an engine test bench for heavy-duty vehicles were applied in the JE05 test cycle and World Harmonized Transient Cycle (WHTC) test conditions in order to evaluate the controllability of transient operations and the effect on emissions. One control method uses dynamometer torque with its inertia correction as the feedback signal (dyno torque F/B control); the other method uses axial torque measured by a flange-type high-response torque meter as the feedback signal (axial torque F/B control). The transient operation controllability using the axial torque F/B control improved compared with the dyno torque F/B control. The results influence NOx emissions in the emissions test cycle, such as JE05 and WHTC, with the engine test bench. Axial torque F/B control could become a more useful technique when it is required to improve the reproducibility of real driving conditions.

A global technical regulation for vehicle environmental performance such as exhaust gases, fuel economy and range has appeared in the issue of WP29 in the United Nations Economic Commission for Europe (UN-ECE). [1] One of major concerns is that battery degradation may influence on the fuel economy deterioration of electrified vehicles such as HEVs. However, numbers of report from automakers about the relation between a fuel economy change and battery performance change are limited. In this paper, we demonstrate the battery performance change in a hybrid vehicle with 105,000 km driving and its fuel economy change. Fuel consumptions of the hybrid vehicle with 1.5 L gasoline engine and 105,000 km driving were compared before and after battery pack replacement. The type of the battery was Lithium-ion. The fuel consumptions with the “state of charge correction” were measured by a chassis dynamometer with Japanese driving test cycle of “JC08 mode” (Fig.1). Before replacing the battery pack, the hybrid vehicle ran with a fuel consumption of 29.24 km/L. Then after replacing the battery ran with a fuel consumption of 29.96 km/L. After the fuel consumption test, the battery pack with 105,000 km driving was disassembled to battery cells. Discharge capacities and internal resistances of the cells were measured. We will discuss the battery performance change and its influence on the fuel consumption rates of the vehicles. [1]https://www.unece.org/trans/main/wp29/introduction.html Figure 1

Flash-boiling occurs when a fuel is injected into a combustion chamber where the ambient pressure is lower than the saturation pressure of the fuel. It has been known that flashing is a favorable mechanism for atomizing liquid fuels. On the other hand, alternative fuels, such as gaseous fuels and oxygenated fuels, are used to achieve low exhaust emissions in recent years. In general, most of these alternative fuels have high volatility and flash-boiling takes place easily in the fuel spray when injected into the combustion chamber of an internal combustion engine under high pressure. In addition the multicomponent mixture of high- and low-volatility fuels has been proposed in the previous study in order to control the spray and combustion processes in an internal combustion engine. It was found that the multicomponent fuel produces flash-boiling with an increase in the initial fuel temperature. Therefore, it is important to investigate these flash-boiling processes in fuel spray. In the present study, the submodels of a flash-boiling spray are constructed. These submodels consider the bubble nucleation, growth, and disruption in the nozzle orifice and injected fuel droplets. The model is implemented in KIVA3V and the spray characteristics of multicomponent fuel with and without flashing are numerically investigated. In addition, these numerical results are compared with experimental data obtained in the previous study using a constant volume vessel. The flashing spray characteristics from numerical simulation qualitatively show good agreement with the experimental results. In particular, it is confirmed from both the numerical and experimental data that flash-boiling effectively accelerates the atomization and vaporization of fuel droplets. This means that a lean homogeneous mixture can be quickly formed using flash-boiling in the combustion chamber. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 369–385, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20117

Original KIVA code cannot take account for the spray and combustion processes of multicomponent fuels. Therefore, it is necessary to produce the sub-models for multicomponent fuel using KIVA code. In this study, the modeling of detailed physical properties and evaporation process for multicomponent fuel was conducted. In addition, the effects of fuel composition in multicomponent fuel on vapor distribution, spray tip penetration, vapor mass and evaporation rate, and sauter mean diameter were numerically investigated by using KIVA 3 V code with this multicomponent fuel spray model. From the numerical results, the spray characteristics of multicomponent fuel varied with a change in mixing fraction in multicomponent fuel. Especially, the evaporation of multicomponent fuel was not necessarily improved, even if much amount of high volatility fuel was mixed in the multicomponent fuel.

Though estimates of the total N 2 O emitted by automobiles differ widely, automobiles are believed to be a significant source of non-agricultural anthropogenic N 2 O emissions. At the Third Conference of the Parties (COP-3) UN Framework Convention on Climate Change, held in Kyoto in 1997, N 2 O was designated as a greenhouse gas whose release into the atmosphere must be reduced. This action increased the need for more accurate estimates of automotive N 2 O emissions. The wide variation in estimates may be attributed to differences in emission test modes, types of catalysts, and levels of catalyst deactivation involved in the tests. In this study, we examined the influence of automotive catalyst deactivation on N 2 O emissions from the perspective of catalyst temperature frequency distribution. Using a model gas and deactivated three-way catalysts (TWCs), we applied the exhaust emission test modes of various countries. The results indicate that the factor behind the increase of N 2 O emissions following catalyst deactivation is not growth in N 2 O generation, but a decline in the N 2 O decomposition capability of the catalyst. It was also found that the effect of catalyst deactivation differs according to the catalyst composition and the emission test mode.

In this paper, the authors report on their investigation of the differences in the amount of information acquired in reading displays for both short periods of time and for one complete reading. Experiments were conducted using continuous and repeated displays. Results show that data acquisition was greater when the display was read repeatedly, even if the total time spent was equal to that of a continuous reading. The authors conclude that even while an observer is not viewing the display, information retention and processing is being carried out in short-term memory, suggesting that this time is effective for acquiring information.