In this paper, we describe the design and evaluation of vehicle-mounted stirling engine. Output target is 1 kW net power from the exhaust gas of driving at 100 km/h in a small hybrid car. The α-type four-cylinder stirling engine arranged in tandem two units to aim compact and low vibration were designed. In addition, from the evaluation results of the previous model⁽³⁾, the new heater was designed. The net power output of 472W was obtained from the equivalent load at the speed of 100 km/h. Recovery rate was 5.1%, and fuel consumption increased 3.4%. It was shown that this stirling engine was effective means of waste heat recovery system. In order to achieve the target power, it is necessary to reduce heat loss of stirling engine.

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High thermal efficiency with low emission can be realized by low temperature combustion using EGR. Alger, T. in SwRI proposed " Dedicated EGR " (a single cylinder run under rich condition and 100% of exhaust gas from this cylinder recirculated into the other cylinders.) to improve burning velocity by CO and H2 that included in EGR gas under high EGR ratio. This study investigates the dependence of burning velocity and flame temperature on equivalence ratio and EGR ratio by the combustion of premixed methane-air. Finally, it confirmed that “ Dedicated EGR ” had a potentiality of improving both thermal efficiency and NO emission.

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The advantages of gasoline direct-injection are intake air cooling due to fuel vaporization which reduces knocking, additional degrees of freedom in designing a stratified injection mixture, and capability for retarded ignition timing which shortens catalyst light-off time. Stratified mixture combustion designs often require complicated piston shapes which disturb the fluid flow in the cylinder, leading to power reduction, especially in turbocharged gasoline direct-injection engines. Our research replaced the conventional shell-type shallow cavity piston with a dog dish-type curved piston that includes a small lip to facilitate stratification and minimize flow disturbance. As a result, stable stratified combustion and increased power were both achieved.

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To improve accuracy of wall-impinging diesel spray CFD under evaporating condition, we examined near wall velocity behavior of impinging jet by using LES. It was found that the near wall velocity profile in impinging jet was different from the profile of the steady wall functions. Based on this knowledge, we made a simple model for boundary condition of impinging jet. The model was integrated to the CFD code KIVA3V, and the test comparing with the wall-impinging diesel spray experiment was carried out. As the result, the behavior of impinging spray calculated by the presented model was well in agreement with that of the experiment.

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The European legislation will bring a restriction on the particle number emission for gasoline direct injection spark ignition engines. Liquid fuel films attached on wall surfaces are presumed to cause the soot emissions during the cold startup period. In this study, soot formation originated in combustion of liquid fuel films was investigated by using a 3D engine simulation. Calculations were performed for Rapid Compression and Expansion Machine model having a bore of 80. 3mm, a stroke of 95.0mm and a compression ratio of 10.5. Results show that liquid fuel films remained until the end of expansion stroke without evaporating when the wall temperature was low, even with the passage of flame. In contrast, liquid fuel films evaporated quickly and the fuel diffused into the cylinder when the wall temperature was sufficiently high. From the above, it was revealed that liquid fuel films have a large influence on the soot generation at an intermediate temperature during the cold startup period. Emission factors of liquid fuel films and soot can be expressed as a function of the wall temperature.

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In a thermoacoustic refrigerator that refrigerates using exhaust heat, the configuration of resonant tubes that connect a thermoacoustic engine and a refrigerator has a dramatic effect on its efficiency. This research focused on a double loop type thermoacoustic refrigerator. Numerical analysis conducted on the relationship of the refrigerator loop and branch resonator length to find a relationship to efficiency. A refrigerator with specifications with the highest efficiency was created. The result was that the conversion efficiency from heat to cold heat reached 22.2%, verifying the validity of this numerical analysis method.

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A novel lubrication model has been developed which considers characteristics of crosshatched surface. The model yields flow factors using crosshatch angle, plateau ratio, and groove depth. The model is applied to the oil film between piston ring pack and crosshatched bore, which predicts increase in oil film thickness and reduction of friction mean effective pressure by 1kPa with reduction of crosshatch angle from 30°to 10°. The effect of friction reduction has been verified using test rig and floating liner engine. The reduction of crosshatch angle has also been confirmed no evil effect on lubricating oil consumption and anti-scuffing performance.

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Air-cooled small gasoline engines used for motorcycles are utilized for personal mobility. They are better in fuel economy than automobiles and have an advantage in an environmental impact. Piston friction reduction is effective for further fuel economy under partial load conditions. Additionally a piston of such an engine must be designed to have durability and reliability under a wide speed range. Therefore piston friction measurement was carried out for an air-cooled small gasoline engine. Piston friction was successfully measured under 5200 rpm. Measured results suggested that oil was starved at mid-stroke under high speed condition.

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A combustion method called Noise Cancelling Spike (NC-Spike) Combustion has been reported in the co-author’s previous paper, which reduces combustion noise in pre-mixed charge compression ignition with split injection. The overall combustion noise was reduced by lowering the maximum frequency component of the noise spectrum. In this paper, we investigates feasibility and controllability of the two-peak heat release rate during high temperature heat release by adding fuel in the adiabatic compression process of pre-mixed gas. The results show that the certain fuel addition timing generates the second heat release, and the interval of peak heat release rate could be controlled.

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An evaporation model available for ethanol-blended fuels has been developed. The model takes into account the high latent heat of vaporization (LHV) of ethanol and the vapor-liquid equilibrium (VLE) of ethanol-n-heptane blends. In the present study, an experimental validation of the developed vaporization model was made through a comparison of single droplet vaporization tests. The calculated results were in good agreement with the experimental data and demonstrated the importance of the LHV of ethanol and the azeotropic behavior derived from the VLE of ethanol-n-heptane blends. Finally, the developed model was incorporated into KIVA3V code and evaporating sprays of ethanol-n-heptane blends were evaluated.

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A lateral torque vectoring differential enhances the vehicle cornering performance by making the torque difference between the right and left wheels of a vehicle. This paper describes a two motor torque difference amplification system which is suitable for a lateral torque vectoring differential of electric powered vehicles. The principle and the mechanism of the system which is proposed by the authors are shown. After the comparison of the making ability of the torque difference with other lateral torque vectoring differentials, the superiority of the system is evaluated.

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We have developed a “direct current resonance“ method as a new wireless power transfer system technology. The direct current resonance is a new technology that makes it possible to convert DC electric energy into electromagnetic field energy. It uses a newly discovered physical phenomenon called an electromagnetic resonance field to transfer electric power. This technology method can enhance energy conversion efficiency because a resonance field is formed directly from the DC power source. It can also reduce the number of power conversion in the power system and achieve greater simplicity and power efficiency. In addition, we can expand the resonance field by use of some resonant devices. A new fundamental design theory for the energy conversion between electrical energy and electromagnetic field energy is discussed. We propose new unified design methods using the magnetic coupling coefficient. We operate the system with GaN FET in 10MHz-class. We show the prototype to demonstrate the availability of the "direct current resonance". Electric power is transferred between some resonant coils to brighten the LEDs.

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The market of the electric vehicle is not large because of their poor cruising range.The electric full flat bus has developed for achieving high driving efficiency and enough cruising range by using 8 direct drive in-wheel motor. It is revealed that the motor can drive 707Nm torque by bench test. The bus realized 912Wh/km driving efficiency and 121km cruising range per charge by test driving.Those performances mean the drive train satisfies driving performance for using passenger buses.

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In order to improve reliability in a permanent magnet synchronous motor of an electric vehicle, a method for estimating magnet temperature which is difficult to measure directly is desired. This paper deals with development of temperature estimation for the motor magnet based on real-time computing of a temperature estimation model. With the aim of accuracy improvement, observer is adopted, and a measure point maximizing likelihood of estimated temperature of the magnet is explored. The result shows that measure points of inner air and coil are optimal for estimating magnet temperature in case of choosing from options which are easy to measure, and improvement of accuracy of estimating magnet temperature is verified.

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We have developed a system that can achieve stable cornering performance and nimble handling by independently controlling the left and right of the rear wheel toe angle. In this paper, we describe the basic principle of control, the structure of this system and the achievement of aims. The purpose of this system is achieving the " INOMAMA handling (at-will handling)" that means let the driver handle the car just like a part of own body. It should lead to safety in all driving scenes and to the fun-to-drive.

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The purpose of this study is reduction of the BPF noise in the automotive cooling fan which performed an eccentric. The low noise engine cooling fan is required with increase in EV, HV now. In addition, space in the engine room such as expansion of the cabin space becomes small as a vehicle trend. So the cooling fan which performed an eccentric is used for the deployment. Therefore it is necessary to decrease the BPF noise affect the tone. This paper described the idea to found the sound source part and flow of the internal flow with the cooling fan which performed an eccentric by using measurement of sound intensity and CFD analysis.

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In this research, we evaluated sound quality of EV driving sound with presentation of driving sound only, under complex stimuli with driving sound and driving image, and under complex stimuli with driving sound, driving image and driving operation. We also evaluated the impression change of driving sound when driving conditions, such as sudden acceleration, slow acceleration, constant speed, and deceleration, were changed. Thus, we grasped the influence of stimulation with visual information or driving operation, and changing driving conditions, to driving sound. Moreover, we proposed the sound quality evaluation method under complex stimuli, which can evaluate quantitatively.

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This paper describes the edge detection algorithm applied to the forward image of the vehicle. We have defined a brightness gradient vector having a direction and magnitude, and we use the scalar product of vectors to quantify the relationship between the edge point and the other edge point. Furthermore we use the sum of the scalar product to determine the edge feature amount. The proposed edge detection algorithm with only one threshold is equivalent to the Canny filter performance with two thresholds. We propose new algorithm that can achieve both performance, i.e. border detection under various situation and noise reduction.

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Traffic accidents occurred before and after sunset in Chiba was analyzed. It was found that the rate of traffic accidents before and after sunset was higher than that of any other times. The rate of fatal accidents during twilight time is much higher than that of any other time, because many fatal pedestrian accidents had occurred during twilight time. But many vehicle headlights during twilight time turned on. Drivers of first vehicle concerned were adversely affected by sun glare, when the sun is located in front of vehicle.

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It is important in the safe driving support system to indicate a risk factor by clear sound image for reducing driver's reaction time. Since the frequency characteristics of acoustic transmission in a vehicle have many dips randomly, the square wave based alert sound with multiple frequency components was chosen. Considering the perspective of acoustic psychology, we focused attention on sound pressure balance with time difference (Haas effect) in the tuning process of sound image generation. The sensory evaluation tests showed that a driver can percept sound image clearly by the Haas effect and, therefore, driver's reaction time is possibly reduced.

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This paper discusses a model-based-controller design for a multi-zone HVAC system for cooling. Air-mass flows of the HVAC system is chosen as input based on the results of optimization on thermal comfort and energy consumption, and we adopt gain-scheduled 𝐻_∞ control to design the robust controller for the change of insolation and ambient temperature. In addition, we apply an anti-windup compensation in order to prevent degradation of the control performance under actuator constraints, then we validate the performance of the control system by simulation.

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A liquid-piston steam engine is suitable for waste heat recovery from automobile exhaust gas since it has high efficiency at low temperature region and high reliability at high temperature. In this work, heat loss from heating section inlet is investigated and new structure is proposed to reduce this heat loss. In addition, the effect of coolant temperature on thermal efficiency is investigated and an opposite trend of conventional thermal engines is found. Thermal efficiency of 8.8% at heating temperature of 270˚C, cooling temperature of 90˚C and operation frequency of 3Hz is achieved with the improved liquid-piston steam engine.

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A debonding fracture criterion of single lap joints is discussed. Two distinct intensities of singular stress fields corresponding to two singular indexes are calculated accurately by the reciprocal work contour integral method. The results show the ratio of the intensities of two types of the singular stress fields is almost the same for the various adhesive geometries. Therefore the criterion can be expressed in terms of the intensity of singular stress field having the stronger singularity when aluminum alloy is bonded by epoxy resin. The proposed method can be applied to evaluating the bonding strength for various structures conveniently.

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To investigate the fatigue fracture mechanism and effects of welded defects on fatigue properties in the cross tension typed spot welded joints using 300 MPa-class SPCC, fatigue tests and finite element analyses were carried out. It was examined spot welded joints have a comparatively high proportion of fatigue crack initiation life against the whole fatigue life. Moreover, it was clarified the welding defect whose size was 60% against the diameter of spot welded area didn’t affect the fatigue strength because there are no significant deference in the stress intensity factor at slit edge regardless the existence of welded defects.

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Generally, the required sound information are different for a driver and other passengers in a vehicle interior therefore the multi-zone sound field control in a vehicle interior can be useful to transfer different sound onto closely located areas. To ends this, the inverse design method based on the least-square solution is conducted with a multichannel audio system. The transfer matrix between the sources and two different seat positions, the driver and rear passenger, are measured for every candidate point of source position and the conditioning process is applied to reduce the redundancy of matrix by selecting the efficient source position and the regularization. With the solution estimated using the matrix after conditioning process, the level difference about 10 ~ 20 dB are achieved between selected two regions.

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