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Historically the high speed diesel engine for commercial vehicles has been developed along with its combustion system in compliance with political and economical changes. After the 1970's, stricter exhaust emission regulations and fuel economy requirements induced combustion developments and application of turbocharged and inter cooled engines. From the late 1980's, high pressure fuel injection has been investigated and recognized as an essential tool for lowering emissions especially of particulate matter. Although turbulence effects on both in-cylinder air motion and during the combustion process are quite effective, they show different phenomena in conventional and advanced high pressure fuel injection systems. In the 1990's, multiple injection with high pressure has been attempted for further reduction of NOx and particulate matter.

The electronic controlled carburetor and ignition system has been developed. In accordance with various working conditions of the engine, the system adjusted corresponding control parameters; air fuel ratio and ignition timing, therefore it could keep the engine working on the optimal conditions. Through analyzing overall performance of the engine based on the experimental data, we had concluded that the specific fuel consumption was improved about 8-10%, and the exhaust emission performance was improved correspondingly after electronic control, the improved ratio was about 10% for HC emission and 97% for CO emission.

When the power or specific fuel consumption is estimated in design process, thermodynamic consideration for the estimation is generally insufficient. Hence, a theory that can estimate these performances accurately is investigated in this paper. As a result of investigation, it is clear that the effect of pumping loss in wide-opene throttle valve operation has to be excluded from the mechanical loss which is measured in the motoring test. It also becomes clear that a new coefficient called pumping loss coefficient ηP has to be considered for the negative work for pumping. From the foregoing, theoretical formulas for estimating the net power Pe and net specific fuel consumption be. which are formed with various efficiencies and coefficients are as follows: It is verified that the estimation from these formulas agree well with the experimental test values using stoichiometric mixture ratio.

A new concept for diesel combustion was investigated by means of numerical simulation, engine experiment, and combustion observation in order to realize a simultaneous reduction of NOx and particulate emission. This concept (HiMICS: Homogeneous charge intelligent Multiple Injection Combustion System) is based on pre-mixed compression ignition combustion combined with multiple injection. Combustion characteristics of HiMICS concept was investigated by comparing with both a standard single injection and a pilot injection. In HiMICS concept, the pre-mixture is formed by a preliminary injection performed during a period from the early stage of the induction stroke to the middle stage of the compression stroke. Modified KIVA-II code was used to predict engine performances and emissions of each injection method. The simulation results show a capability of considerable improvement in the trade-off relation between NOx emissions and fuel consumption of HiMICS.

This paper presents technical solutions and a development process to accomplish not only superior fuel economy but also excellent driveability with a turbocharged diesel engine for heavy duty trucks. For better fuel economy, one of the basic considerations is how to decrease the friction losses of the engine itself while keeping the required horsepower and torque characteristics. A high boost turbocharged small engine offers this possibility, but it has serious disadvantages such as inferior low speed torque, poorer accelerating response, insufficient engine braking performance, and finally not always so good fuel consumption in the engine operating range away from the matching point between engine and turbocharger. These are not acceptable in complicated traffic conditions like those in Japan - a mixture of mountainous and hilly roads, city road with numerous traffic signals, and freeways.

Described herein is the tuning of the combustion system of a direct injection type diesel engine to obtain low emission level and better fuel economy. Though the most important method of emission control for a direct injection system is considered to be timing retardation, it brings a higher level of smoke density and fuel consumption. In order to remove these faults, the authors developed a new combustion system based on a newly designed intake port which provides a favorable local mixing of fuel droplets and air in the combustion chamber for ignition by means of air turbulence. This new combustion system was analyzed with high speed photographs which were taken from the underside of the piston to enable observing the whole combustion chamber. Favorable characteristics of ignition and burning pattern of the new system were recognized by this analysis.

In Japan, about 5.6 billion tons of freight are transported annually and 90% of this figure is supported by trucks. Among them, the heavy vehicles of GVW 20ton are employed as one of the main means of such transportation and they are produced about 40,000 units annually. For these trucks, over 80 types of diesel engines have been developed during the past 20 years. Today, there are more than 30 domestic types. The engine displacement ranges from 8.8 to 18.0 liters and the maximum output spreads from 270hp (199kW) to 380hp (280kW). The naturally aspiration type occupies 70% and the turbocharged or turbo-intercooled type takes the remaining portion. The authors present the design concept and the technical background which are involved in the above-mentioned engines. They also describe the technology which concerns combustion, gas exchange, construction, electronic control, etc. and the ‘total power system’ (some simultaneously managing system) formulated to realize such engines.

This paper discusses the compact structure, innovative and unique approach of high performance spiral coil sub-cooled condenser for compact power plant/engine applications. The motivation behind this study is to reduce the engine emission by improving the coefficient of performance for air-conditioning unit. Since the air conditioning system is the most power consumption units after the power plant, so it significantly affects the fuel consumption and the hazardous gas emissions. In the air condition cycle, the condenser unit is addressed as one of the important devices, and thus, the author tried to reduce the energy consumption by improving the performance of the condenser. The most advantage points of this study is to use spiral coil sub-cooled condenser, which elaborates the effect of secondary flow generation inside the fluid and is known as the Dean’s effect.

In motorcycle market, there is demand for technology that makes it possible to drive fast safely. One such technology has already been commercialized; control that prevents front lift while enabling maximum acceleration performance. We have developed a more accurate version of this control. In order to maximize acceleration performance, it is necessary to keep front lift angle as close to zero as possible. Reducing output driving force helps to keep the front lift angle low, but if output driving force is reduced too much, it will degrade acceleration performance. Feedback control that reduces output driving force when front lift is detected is effective for optimizing this trade off, but increasing feedback gain too much to reduce front lift angle will cause output driving force to change suddenly, making for a less comfortable ride.

In order to get better results in the Formula SAE of Japan, it is necessary to develop a small displacement engine with an ideal fuel consumption rate. Therefore, the authors started to improve an existing engine by combining with glow plug heated sub-chamber and lean burn. Lean burn conditions are usually adopted in gasoline engines, having the advantages of high specific heat ratio, low pump loss, and low cooling loss due to requiring a decreased combustion temperature. The combination of these elements can be expected to vastly improve thermal efficiency and fuel consumption. Unfortunately, however, when the mixture becomes lean, the ignition delay increases, and the flame propagation speed reduces. This leads to an increase in combustion fluctuation. The authors intend to solve this problem by installing a glow plug in a newly designed sub-chamber. This type of device would usually be used to heat the sub-chamber of a diesel engine to solve the cold start problem.

This paper oriented towards spiral coil sub-cooled condenser (SCSCC) which is used for the automotive air conditioning system. Therefore, the effect of curvature diameter has been carefully measured by CFD as it reduces/intensify the centrifugal force. This centrifugal force is responsible for Dean vortices and leads to the generation of secondary flow inside the refrigerant. By taking advantage of this secondary flow, the performance of the SCSCC can be improved. CFD analysis comprises curvature diameter from 13mm to 110mm, which varied the Dean number from 7577 to 2605. The author tried to evaluate the complicated phenomena that occurred within the SCSCC. However, the turbulent kinetic energy which is one of the critical factors of heat transfer coefficient illustrates 0.009m2/s2 and 0.006m2/s2 for large and small Dean number, respectively, toward the outer side of the channel.

This research focuses on the improvement of torque at the middle engine speed of a motorcycle engine with resonance supercharging. The resonance supercharging intake system is realized with a simple modification to the intake collector geometry. A one-dimensional computational model is employed to simulate the pressure wave propagation and to optimize the configuration of it. The experiments confirmed the increase in the engine torque for the entire operation range and the maximum gain of 33% was achieved at 8500rpm. The resonance effect is further investigated through three-dimensional simulation, in which the intake airflow rate, static pressure distribution are analyzed.

In this study, we have evaluated the performance of undertray and rear wing in formula SAE. The undertray was adopted to increase the driving force transmission. And in order to further increase the driving force and prevent the car from oversteering in high speed areas, a rear wing was mounted. Finally, by mounting these aerodynamic devices, driving force increased by 41% (undertray 14%, rear wing 27%) at the speed of 90km/h, and by calculating the value of stability factor measured by cornering power, improvement of the vehicle's oversteering tendency was confirmed.

1 Many environmental problems, such as global warming, drain of fuel and so on, are apprehended in all over the world today, and down-sizing is one of the wise ways to deal with these problems. It is significant that a decrease of the engine power must not be produced by using a small displacement engine, so more efficient engine system should be designed to increase the torque with a little fuel. This study achieves an improvement of efficiency for mounting the super charging system on the small displacement engine. As a result, comparing a super charged engine and a naturally aspirated one to drive the same course and laps, fuel consumptions are 2547 [cc] and 3880 [cc], respectively, and an improvement of fuel consumption is 52%. Designing points to mount super charging system is introduced below. 1 It can be forecasted that intake air blow-by gas at the combustion chamber is increased in low engine speed because engine for motor cycle is used.

The paper reviews the experimental development of fuel economy of engine powering the 2012 Formula SAE single seat race car of the University of Sophia. The balance of high power and low fuel consumption is biggest challenge of racing engine. It was found that improving the efficiency of engine by supercharging as a way to achieve that. In order to adapt the supercharger for the engine, the important design points are below: It was found that intake air blow-by gas at combustion chamber is increased in low engine speed. To improve that, the valve overlap angle was changed to adopt supercharged engine and improve effective compression ratio. Typically the racing engine demands maximum torque for performance but that does not imply that the air fuel ratio should be rich than theoretical. The point is the maximum torque of the engine is proportional to the amount of air intake. Therefore, supercharged engine is possible to increase the supercharging pressure for bigger torque.

The electric power steering (EPS) is increasing its number since there are many advantages compared to hydraulic power steering. The EPS saves fuel and eliminates hydraulic fluid. Also, it is more suitable to the cooperation control with the other vehicle components. The EPS is now expanding to the heavier vehicle with the advance in the power electronics. In order to meet customer's needs, such as down-sizing, lower failure rate and lower price, we have developed the new motor control unit (MCU) for the EPS. The motor and the electric control unit (ECU) were integrated for the better installation. We adopted new technologies of redundant 2-drive design for more safe EPS. “2-drive Motor Control technology” which consists of dual winding, two torque sensors and two inverter drive units. In our developed MCU, even if there is a failure in one of the drive unit, the assistance of the EPS can be maintained with the other drive unit.

This book examines the development of the engine from a historical perspective. Originally published in Japanese, The Romance of Engines' English translation offers readers insight into lessons learned throughout the engine's history. This book belongs on the bookshelves of all engine designers, engine enthusiasts, and automotive historians. Topics covered include: Newcomen's Steam Engine The Watt Steam Engine Internal Combustion Engine Nicolaus August Otto and His Engine Sadi Carnot and the Adiabatic Engine Radial Engines; Piston and Cylinder Problems Engine Life Problem of Cooling Engine Compartments Knocking; Energy Conservation Bugatti; Volkswagon Rolls Royce Packard Daimler-Benz DB601 Engine and more!

The reduction of CO2 emissions is one of the most important challenges for the automotive industry to contribute to address global warming. Reducing friction of internal combustion engines (ICEs) is one effective countermeasure to realize this objective. The improvement of engine oil can contribute to reduce fuel consumption by reducing friction between engine parts. Electrification of ICE powertrains increases the overall efficiency of powertrains and reduces the average engine oil temperature during vehicle operation, due to intermittent engine operation. An effective way of reducing engine friction is to lower the viscosity of the engine oil in the low to medium temperature range. This can be accomplished while maintaining viscosity at high temperatures by reducing the base oil viscosity and increasing the viscosity modifier (VM) content to raise the viscosity index (so-called “flat viscosity” concept).

In recent years, the realization of carbon neutrality has become an activity to be tackled worldwide, and automobile manufacturers are promoting electrification of power train by HEV, PHEV, BEV and FCEV. Although interest in BEV is currently growing, vehicles equipped with internal combustion engines (ICE) including HEV and PHEV will continue to be used in areas where conversion to BEV is not easy due to lack of sufficient infrastructures. For such vehicles, low-viscosity engine oil will be one of the most important means to contribute to further reduction of CO2 emissions. Since HEV requires less work from the engine, the engine oil temperature is lower than that of conventional engine vehicles. Therefore, the reduction of viscous resistance in the mid-to-low temperature range below 80°C is expected to contribute more to fuel economy. On the other hand, the viscosity must be kept above a certain level to ensure the performance of hydraulic devices in the high oil temperature range.