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This paper is the part II of the report of IDIS (Isuzu Dual Fuel Injection System) IDIS was applied to 5.8 liter L-6 DI diesel engine. The outlines of improved and simplified system, rate of alcohol blend, exhaust emission and performance of the engine were shown in the case of methanol blend as well as ethanol blend. For preventing the torque deviation just after start and end of alcohol blend caused by difference of calorific values between alcohol and diesel fuel, improved system with additional check valve was developed. It was confirmed that replacement of about 30% of diesel fuel by alcohol was possible without any fundamental problems. Basically no modification of the engine was required except the adoptions of new fuel tank and fuel line with low pressure pump for alcohol, some check valves and magnetic valves, a microswitch on the fuel lever and the new delivery valves with increased retraction volume.

In order to clarify future automobile technologies and fuel qualities to improve air quality, second phase of Japan Clean Air Program (JCAPII) had been conducted from 2002 to 2007. Predicting improvement in air quality that might be attained by introducing new emission control technologies and determining fuel qualities required for the technologies is one of the main issues of this program. Unregulated material WG of JCAPII had studied unregulated emissions from gasoline and diesel engines. Eight gaseous hydrocarbons (HC), four Aldehydes and three polycyclic aromatic hydrocarbons (PAHs) were evaluated as unregulated emissions. Specifically, emissions of the following components were measured: 1,3-Butadiene, Benzene, Toluene, Xylene, Ethylbenzene, 1,3,5-Trimethyl-benzene, n-Hexane, Styrene as gaseous HCs, Formaldehyde, Acetaldehyde, Acrolein, Benzaldehyde as Aldehydes, and Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(k)fluoranthene as PAHs.

Combinations of swirl flow and tumble flow generated by 13 types of swirl control valve were tested by using both impulse steady flow rig and LDV. Comparison between the steady flow characteristics and the result of LDV measurement under motoring condition shows that tumble flow generates turbulence in combustion chamber more effectively than swirl flow does, and that swirling motion reduces the cycle by cycle variation of mean velocity in combustion chamber which tends to be generated by tumbling motion. Performance tests are also carried out under the condition of homogeneous charge. Tumble flow promotes the combustion speed more strongly than expected from its turbulence intensity measured by LDV. It is also shown that lean limit air fuel ratio does not have a strong relation with cycle variation of mean velocity but with turbulence intensity.

In the course of developing a low-emission manual transmission vehicle, coast surge in the fore-and-aft direction resulting from the installation of certain emission-control devices was sometimes experienced immediately after the initiation of vehicle deceleration. Our investigation revealed that this vehicle surge was caused by combustion irregularities in a sequence of combustion-misfire-intense combustion events occurring every several cycles. A new combustibility standard. Gt/Feff, defined as the ratio of total cylinder mixture weight Gt to effective fuel weight Feff, was found to predict combustibility and irregular combustion over the entire mixture range. As a result, driveability during deceleration was improved by modifying key emission-control components.

Turbocharged diesel engines prevail not only in the European and American markets, but in the Japanese market. But many problems due to higher brake mean pressure have not been cleared especially in the field of reliability and durability. Torsional vibration is one of remained problems and particularly, on the occasion of low temperature, dynamic behavior of crankshaft and torsional damper has been unknown heretofore. Furthermore, combustion pressure which is exciting force for torsional vibration has not been grasped in detail. Therefore, this paper deals with experimental studies which were conducted in a special cold test ceil using a turbocharged diesel engine for automotive use installed with rubber damper. It has been found that torsional vibration of crankshaft gets bigger at low temperature than at normal temperature. On the contrary, distortion of damper rubber shows nearly zero. This is because stiffness of damper rubber becomes higher due to low temperature.

Three-dimensional computation has been applied to analyze combustion and emission characteristics in direct-injection diesel engines. A computational code called TurboKIVA was used to investigate the effects of the swirl ratio, one of the fundamental factors related to combustion control, on combustion characteristics and NOx and soot emissions. The code was first modified to calculate soot formation and oxidation and the precise behavior of fuel drops on the combustion chamber wall. As a result of improving calculation accuracy, good agreement was obtained between the measured and predicted pressure, heat release rate and NOx and soot emissions. Using this modified version of TurboKIVA, the effects of the swirl ratio on NOx and soot emissions were investigated. The computational results showed that soot emissions were reduced with a higher swirl ratio. However, a further increase in the swirl ratio produced greater soot emissions.

A combined computational fluid dynamics (CFD) and finite element (FE) analysis approach has been developed to simulate in the early stages of design the temperature distribution and estimate the thermal fatigue life of an engine exhaust manifold. To simulate the temperature distribution under actual operating conditions, we considered the external and internal flow fields. Digital mock-ups of the vehicle and engine were used to define the geometry of the engine compartment. External-air-flow simulation using in-house CFD code was used to predict the flow fields in the engine compartment and the heat transfer coefficients between the air and the exhaust manifold wall at various vehicle speeds. Unsteady-gas-flow calculation using the STAR-CD thermal- fluids analysis code was to predict the heat transfer coefficients between the exhaust gas and the manifold wall under various operating conditions.

The new Nissan 1.7 liter 4 cylinder diesel engine has been developed to meet the social requirements for energy conservation. The main objective was to improve fuel economy without sacrificing driveability, and this has been achieved by minimizing engine weight, reducing mechanical friction loss and optimizing the combustion system. The CA series gasoline engine, which is known for its light weight, was chosen as the base engine for dieselization. The swirl chamber combustion system used for the LD28 engine was modified to satisfy the requirements for high power, good fuel economy and low noise. Engine noise has been reduced with the aid of several analytical methods such as laser holography. Special attention has been paid to the reduction of diesel knock which is most offensive to the ear. To install this engine in a small FWD vehicle transversely, much effort went into the minimizing of the engine length and width.

A block-on-ring friction and wear testing machine (LFW-1) was used as a test method for making fundamental evaluations of the effect of the Belt-Drive Continuously Variable Transmission(B-CVT) fluid on the friction coefficient between the belt and pulleys. The results confirmed that this method can simulate the friction phenomena between the belt and pulleys of an actual transmission. The mechanism whereby ZDDP and some Ca detergents improve the torque capacity of a B-CVT was also investigated along with the effect of the deterioration of these additives on the friction coefficient. It was found that these additives form a film, 80-90 nm in thickness, on the sliding surface, which is effective in increasing the friction coefficient. The friction coefficient declined with increasing additive deterioration. The results of a 31P-NMR analysis indicated that the decline closely correlated with the amount of ZDDP in the B-CVT fluid.

The demands on valve seat insert materials, in terms of providing greater wear-resistance at higher temperatures, enhanced machinability and using non-environmentally hazardous materials at a reasonably low cost have intensified in recent years. Due therefore to these strong demands in the market, research was made into the possibility of producing a new valve seat insert material. As a result a high speed steel based new improved material was developed, which satisfies the necessary required demands and the evaluation trials, using actual gasoline engine endurance tests, were found to be very successful.

Generally, cobalt-contained sintered materials have mainly been applied for exhaust valve seat inserts (VSI). However, there is a trend to restrict the use of cobalt as well as lead environmental law, and cobalt is expensive. To solve these problems, a new exhaust VSI on the assumption of being cobalt and lead free, applicable for conventional engines, having good machinability, and with a reduced cost was developed. The new exhaust VSI is a material dispersed with two types of hard particles, Fe-Cr-C and Fe-Mo-Si, in the matrix of an Fe-3.5mass%Mo at the ratio of 15 mass % and 10 mass % respectively.

New technologies are needed to reduce cold-start emissions in order to meet the more stringent regulations that will go into effect in Europe (EC2000 or EC2005) and in California (ULEV), especially for larger engines such as 6- and 8-cylinder units. One new technology in this regard is the electrically heated catalyst (EHC). However, the use of EHCs alone is not sufficient to achieve the necessary reduction in emissions. This paper discusses techniques for effectively combining the elements of an EHC system, including the introduction of secondary air into the exhaust, improved control of the air/fuel ratio, and an electric power supply method for EHCs. It is shown that it is more effective to promote exothermic reactions in the exhaust manifold than at the EHC. A suitable method for this purpose is to introduce secondary air into the exhaust near the exhaust valves.

Although automotive electronics was initially applied as a substitute for mechanical parts, this technology has the potential to achieve effective combinations of mechanical functions. A case in point is the successful resolution of fuel consumption and exhaust emission problems by effectively integrating engine control and catalyst technologies. LSI technology has also been incorporated into automotive electronics and established as a fundamental engine control tool. Thanks to LSI technology, particularly the use of microprocessor techniques, conventional machine design problems have been transformed into logical design ones. In the next stage of application, automotive electronics is expected to provide further benefits including a more comfortable ride, an improved human-machine system interface, and an advanced communications system between vehicles and other telecommunications stations.

This paper describes the numerical and experimental approaches that were applied to study swirl injectors that are widely used in direct-injection gasoline engines. As the numerical approach, the fuel and air flow inside an injector was first analyzed by using a two-phase flow analysis method [VOF (Volume of Fluid) model]. A time-series analysis was made of the flow though the injector and also of the air cavity that forms at the nozzle and influences fuel atomization. The calculated results made clear the process from initial spray formation to liquid film formation. Spray droplet formation was then analyzed with the synthesized spheroid particle (SSP) method. As the experimental approach, in order to measure the cavity factor that represents the liquid film thickness, nozzle exit flow velocities were measured by particle image velocimetry (PIV).

The energy crisis and rising gas price in the 2000s led to a growing popularity of hybrid vehicles. Hyundai-Kia Motors has been challenging to develop the new efficient eco-technology since introducing the mild type compact hybrid electric vehicle for domestic fleet in 2004 to meet the needs of the increasing automotive-related environmental issues. Now Hyundai has recently debuted a full HEV for global market, Sonata Hybrid. This system is cost effective solution and developed with the main purpose of improving fuel consumption and providing fun to drive. Presenter Seok Joon Kim, Hyundai Motor Company

This paper presents a swiring flow type jet pump which has been developed and in put into practical use in transferring fuel between sumps in saddle-shaped fuel tanks. The pump is driven by the force of excess fuel returning from the engine. The major structural features of the pump are described along with its performance. Various problems encountered in the process of developing the pump are discussed along with the technologies developed to resolve them. Particular attention is focused on the effects that the geometries if the nozzle, throat and swirling groove have on fuel transfer efficiency. The results of experiments carried out to analyze these correlations are also presented.

Since a 4-valve engine is less flexible in the design and location of the intake ports as compared with a conventional 2-valve engine, there are some difficulties in strengthening the air motion, including swirl and turbulence, in order to achieve stable combustion under lean mixture operation. This study examined air motion imporvements of 4-valve engine that result in a stable combustion with a lean mixture. These improvements are brought about by the installation of a swirl control valve in each intake port. The results of this study have clarified that the lean stable limit was extended from an air-fuel ratio of 21.5 to 26.3 under a partial load, by optimizing the location and diameter of aperture of the swirl control valve.

Based on experimental analysis, the generation mechanism of abnormal exhaust noise which is characterized by an intermittent high frequency aetallic sound, is clarified by bench testing of a FWD vehicle. The noise is caused by large amplitude pressure waves (finite amplitude waves) in the exhaust pipe. They are amplified due to interference between reflected waves and subsequent waves from the engine, and are finally transformed into shock waves in the propagation process along the exhaust pipe, resulting in abnormal exhaust noise. By theoretical analysis of finite amplitude waves, the wave profile in the propagation process and the transition distance to the shock wave can be solved analytically where the assumptions of mass, momentum, and energy conservation are valid, until the moment of shock wave formation. The transition distance is a key parameter in analyzing the growth and existence of shock waves.

To improve the fuel economy via high EGR, combustion stability is enhanced through the addition of hydrogen, with its high flame-speed in air-fuel mixture. So, in order to realize on-board hydrogen production we developed a fuel reformer which produces hydrogen rich gas. One of the main issues of the reformer engine is the effects of reformate gas components on combustion performance. To clarify the effect of reformate gas contents on combustion stability, chemical kinetic simulations and single-cylinder engine test, in which hydrogen, CO, methane and simulated gas were added to intake air, were executed. And it is confirmed that hydrogen additive rate is dominant on high EGR combustion. The other issue to realize the fuel reformer was the catalyst deterioration. Catalyst reforming and exposure test were carried out to understand the influence of actual exhaust gas on the catalyst performance.

Diesel engines have attracted more attention in recent years as one means of reducing carbon dioxide (CO2) emissions from motor vehicles. One of the major issues for diesel engines is exhaust emissions performance. Diesel engines also face various difficulties in providing the driving force demanded by the driver because of their greater inertia than that of gasoline engines. Meanwhile, continuously variable transmissions (CVTs) have been popularized as gearboxes that execute ratio changes continuously without generating shift shock. The aim of this research is to achieve higher levels of drivability and exhaust emissions performance by mating a CVT to a diesel engine and making maximum use of the continuous ratio change capability. An integrated engine-CVT control algorithm that can freely set the driving force and also the engine operating conditions for generating that driving force has been developed through this study.