A heat transfer model is developed to simulate temperature of paper in and outside fuser nip considering water evaporation and latent heat consumption in paper. The model is based on measuring temperature of paper using an experimental apparatus which presses two sheets of paper between two flat heated plates. In the experiment, it is found that in the inside of paper latent heat consumption starts and temperature elevation rate changes over 100℃, and in the outside of paper latent heat consumption is little. The model is developed to define temperature-rise coefficient and multiply it by heat flux of paper in heat equation. Caluculation results of temperature of paper heated in fuser nip in this model indicate agreement with experimental results, as well as in a model considering no water evaporation. It is suggested that the temperature of paper is nearly unaffected by the latent heat consumption in paper.

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The purpose of this experiment is to provide basic understanding about a film drying process for future applications. For elucidation of the detailed behavior of surface flow and the influence by the shear stress of the wind, forced-convection drying with air jet was observed. PVA (polyvinyl-alcohol) aq.sol. was coated on a glass plate. A tracer particle was distributed on the liquid film surface. Coating solutions were photographed with a digital camera. Image analysis was performed from visualized surface flow of the liquid film. It was observed that a convection occurred on the liquid film surface of the PVA aq.sol. When viscosity was smaller, higher velocity of free surface flow was found.

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We have been developing high efficient liquid cooling system in the high heat density data centers and telecommunication buildings. The cooling system cools CPU by liquid, and transfers heat from CPU to outside. The cooling device in this system is required to be high-efficient and applied to multi-CPU. Then, we propose a natural circulation type cooling device having multiple evaporators for multi-CPU. This device transfers heat from CPU to rack and exchanges heat with cooling device outside rack. The design conditions and effectiveness of this cooling device are examined. Flow fields in this cooling device which is changed by the amount of heat are clarified by thermo fluid simulation.

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We studied a melting phenomenon of a paraffin plate and a flow into a hole in an acryl block during a model rilling groove process. Changes of temperature and geometry of the paraffin plate were experimentally measured for three heating methods: heating the bottom surface of the acryl block with a hotplate, heating the top surface of the paraffin plate with a dryer, and heating the center of the paraffin plate with a halogen lamp. Changes of temperature and melting region were calculated using an enthalpy method. Flow of liquid paraffin plate was calculated using a particle method.

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The purpose of this research is phase change characteristic evaluation of the nanosuspension type heat storage as latent heat material. The target heat storage zone of this study is 50-100℃ as for using of hot spring heat or factory exhaust heat. Tetracosane (50.6℃ of melting point) is used for dispersion material as a latent heat storage material of a nanosuspension. Tetracosane in the nanosuspension is dispersed by about 200 nanometers of average particle diameter in continuous water phase. A latent heat storage material is dispersed by using an ultrasonic homogenizer. This paper deals with the phase change characteristics that estimated by using differential scanning calorimeter. The heating rate and the composition of tetracosane are chosen as experimental parameter.

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An ammine complex formation reaction with strontium chloride is promised to storage a waste heat up to 90 ℃ and to release its heat at atmospheric temperature up to 0 ℃. In this reaction system, heat transfer rate is an important factor in determining heat release performance. In this study, overall reaction rate of the reactant packed bed was measured using volumetric method to evaluate the influence of the thickness of the packed bed. As a result, the smaller thickness led to larger reaction rate. When the thickness of the packed bed was 2.5mm, the reaction time was 6 times or more long than that of 0.5mm. Besides, the heat resistance was quantified by another experiments as well as and the heat transfer simulation. As a result, the effective thermal conductivity of SrCl_2 packed bed was λ_<eff>=0.18W/m/K and thermal contact resistance was R_c=2.3×10^<-3>m^2・K/W. It was also found that the simulation results agree with the heat release behavior.

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Chemical heat pump is a system to upgrade exhaust heat to useful heat. Upgrading unused low temperature exhaust heat by chemical heat pump can contribute to improvement of energy efficiency. In this study, the hydration reaction of CaCl_2, which was able to use exhaust heat of less than 100 degree C, was selected. In this experiment, the actual equipment was simulated, and the experimental output characteristic was evaluated. As a result of the experiment, 60 degree C rise in temperature was shown with the use of the chemical heat pump. And, the coefficient of performance (COP) was 0.52. The CaCl_2/H_2O chemical heat pump is able to use more than 50% of energy of the exhaust heat. Furthermore, pump power for circulating the heat medium oil was less than 5% of the heat output.

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Metal hydride heat pump (MHHP) shows low cooling performance due to the low effective thermal conductivity of metal hydrides (MH) particle bed. In this paper, aiming at improving the heat transfer of MH particle bed as well as enhancing the operating characteristic of the MHHP system, the metal hydride sheet (MH sheet), which consists of MH powder, aramid pulp (AP) and carbon fiber (CF), was inserted into the metal hydride reactor. The effective thermal conductivity was measured and the effects of the mass ratio were also studied. It was found that besides the share of carbon fiber, the stiffness of sheet was also an important factor, especially in the high-pressure situation. Additionally, with the application of the proposed MH sheet, a small MHHP model was established and its cooling power was evaluated to identify the influence of MH sheet on heat and mass transfer. It was indicated the selected MH sheet did accelerate the rate of heat transfer in each reactor during regeneration and cooling processes.

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Considering an application of oscillating heat pipes (OHPs) for thermal management in space satellites, heat transport characteristics of OHP with ammonia as a working fluid in the low temperature region are investigated experimentally. In this research, the maps of both the maximum heat transport rate and the maximum effective thermal conductivity as heat transfer performances of OHP under constant heat flux condition are widely obtained. The heat transfer performances of OHP filled ammonia 57 wt% under isothermal heating condition are investigated. Under both constant heat flux and isothermal heating conditions, OHPs work according to the almost same heat transport mechanism. In the case of isothermal heating condition, higher pressure difference is required to activate OHPs than constant heat flux condition.

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Current compression ignition strategies which can achieve high thermal efficiency and ultra-low emissions such as dual-fuel PCI combustion and gasoline direct injection compression ignition have utilized stratified fuel mixture to optimize combustion processes. Thus this paper investigated the more detailed relation between equivalence ratio distribution and history of heat release rate. The results concluded that richer mixtures closer to stoichiometric ratio increase heat release rate because the ignition timing of the mixture is less dependent on equivalence ratio so that the mixtures tend to ignite simultaneously, and the advanced ignition of the richer mixture increases ambient temperature while inducing the ignition of surrounding leaner mixture.

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For controlling ignition of HCCI engine fueled by biomass gas, the effect of ozone addition was investigated. In previous experiment, it was shown that ignition timing is advanced by ozone addition. In this paper, the chemical reactions and the mechanism of ignition advance by ozone addition were investigated by calculation with erementaly reactions. As a result, the heat releace was divided into two stages under the influence of O radical, produced by thermal decomposition of ozone. Moreover, Hydrogen peroxide was produced after the first combustion, and the second ignition was advanced by OH radical produced by Hydrogen peroxide.

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Homogeneous charge compression ignition is promising a new combustion system reducing NOx and PM simultaneously without any penalty of fuel consumption. However, the operational range of the combustion system is limited because of some issues such as poor control of ignition timing and the excessive rate of pressure rise. In this study, a new combustion system based on the HCCI combustion process have been proposed. The combustion chamber of the engine is divided into two part, one is in the cylinder head, small chamber, another is in cylinder, large chamber. On the combustion system, at first compression ignition takes place in the small chamber, then, the burned gas ejected into the large chamber ignite the mixture in the chamber. The combustion process in the large chamber is aimed to go on same manner of the HCCI combustion process. This paper presents performance, exhaust emission and combustion characteristics of the combustion system. Test results show indicated thermal efficiency was almost same as or slightly higher than diesel engine. However, NOx emission was higher than ordinary HCCI engines.

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Homogeneous Charge Compression Ignition (HCCI) engine has attracted attention for its high heat efficiency and low emissions. But the fuel research is necessary because the ignition timing relies heavily on fuel. Additionally octane number cannot be applied for HCCI engine because of broad operation condition such as intake air temperature, engine speed and intake O_2 concentration. Wherein index of HCCI engine (HCCI index) is developed and confirmed that it can be applied for variety operation conditions.

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A simplified model of the intake and exhaust gas flow system for an in-line four cylinder HCCI engine with the exhaust rebreathing system was constructed. The model predicted the mass of EGR and its accuracy was verified by comparing with various experimental results. In addition, ignition timing was calculated by using the predicted mass of EGR. The results show a good agreement with experimental results and the availability of the model in ECU is indicated for its fast calculation time.

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Effects of large-amount dilutions of exhaust gas recirculation (EGR) and dedicated-EGR (DEGR) on the ignition characteristics of stoichiometric methane-air premixed air were experimentally studied by using a micro flow reactor. The flames were formed for various EGR/DEGR ratios and equivalence ratios Φ_A in the DEGR cylinder Stable flames and oscillating flames were observed; the combustion characteristics varied because the mixtures were highly diluted with EGR/DEGR gases. Their ignition temperatures were defined by the positions of the flames referred to a measured temperature profile in the quartz tube. Since EGR gas is composed of inert species such as N_2 and CO_2, the ignition temperatures of the premixed gas with EGR gas were higher than that without EGR gas; the EGR gas dilution interferes the ignition timing in reciprocating engines. On the other hand, the ignition temperature of the premixed gas with the dilution of DEGR gas whose equivalence ratios correspond to Φ_A = 1.6 and 1.8 were lower than that with EGR gas. This is because highly-reactive intermediate species such as H_2 and CO. Particularly, the ignition temperatures of the premixed gases highly diluted (40%) with DEGR gas of Φ_A = 1.6 and 1.8 were lower than that without EGR gas or DEGR gas. Therefore, it was found that gases with DEGR have potential for shorting the ignition delay.

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To understand the onset and propagation of low temperature flames in the cylinder of internal combustion engine, we have tried to reproduce the observed result of rapid compression experiment done by Kojima and Katsumi, using the detailed chemical kinetic model of n-butane autoignition developed by Curran, et al. and a commercially available 3-D numerical fluid dynamics code (CONVERGE). Although the onset of hot flame in the experiment occurs much earlier than that in our calculation, the onset and propagation of cool flame in the calculation fairly agree with those in the experiment. As for the onset and propagation of blue flame and hot flame, we can understand the details that could not be obtained from the insufficiently time-resolved experimental photographs. For example, each propagation of cool, blue, and hot flames corresponds to the movement of mol-fraction peak or the expansion of high-density region of three radicals, HCO, HO_2, and OH.

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The ignition delay dependence on fuel ignitability and operating conditions including intake oxygen concentrations and intake gas temperatures were investigated in a DI diesel engine with a common-rail fuel injection system and cooled EGR. Increases in ignition delays when reducing the intake oxygen concentration from 21% to 15% are larger with lower ignitability fuels. The ignition delay dependence on intake oxygen concentration is weaker with higher ignitability fuels and stable operation is possible under the low intake oxygen concentrations. Increases in ignition delays when lowering intake gas temperatures is slightly larger with lower ignitability fuels. Under practical conditions with the intake oxygen concentration between 21% and 15% and the intake gas temperature between 40℃ and 100℃, the changes in ignition delays with the intake oxygen concentration are more significant than with intake gas temperature.

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Premixed diesel combustion is one of the most promising technologies to simultaneously establish a higher thermal efficiency and lower exhaust gas emissions. In this paper, new-generation ceramic-combined prototype pistons were applied to evaluate the potential in a diesel engine with modern combustion systems. The experimental result shows that premixed diesel combustion in the engine with the ceramic-combined piston has almost comparable performance and exhaust emissions. With the ceramic combined piston, the cooling loss is reduced while the exhaust loss is increased, resulting in the unchanged indicated thermal efficiency.

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An in-cylinder gas model is developed to analyze thermal efficiency of a conventional diesel engine using open source chemical kinetics software, Cantera, working on MATLAB^[○!R]. CHEMKIN-formatted thermodynamic properties of a diesel surrogate are implemented to perform a highly accurate cycle analysis. Thermodynamic factors resulting in the difference between a practical diesel engine cycle and the air standard Otto cycle are then quantitatively estimated: loss due to specific heat of 8.0%pt, chemical equilibrium loss of 0.4%pt, evaporation loss of 1.0%pt, time loss of 4.2%pt, heat loss of 5.6%pt, pumping loss of 2.3%pt and friction loss of 4.7%pt. In addition, a temporal pattern of reaction rate of progress is optimized for brake thermal efficiency on Wiebe-function basis under adiabatic condition.

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This study is aiming at an optimal use of bio-gas for the small distributed power-generation system making good use of its characteristics. The diesel dual fuel (DDF) operation is paid attention, which is easily remodeled from a diesel generator on the market to supply low-calorific gaseous fuels. Though there are many studies focused on the performance of DDF operation when bio-gas is supplied to diesel engine, the response to momentary change of demand of electricity or amount of gas supply is not guaranteed. In this study, according to the background above, the performance or stability of output on regular DDF operation with methane is, first, examined by experiment and specific characteristics of the diesel generator is, secondly, examined on the transient operation like momentary change of load or methane supply. As a result of experiment, it is found that the diesel generator which is used through this study is highly able to follow the momentary change of load or gas supply, and the combustion of methane progresses steadily at the both conditions of small quantity of oil (large quantity of methane) and the large quantity of oil (small quantity of methane).

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For an effective utilization of various gaseous fuels, the general-purpose diesel engine with a conventional jerk-pump system have been used to efficiently convert to the power in many cases through the diesel dual fuel (DDF) operation. In this study, natural-gas fuel is supplied into the intake air-flow of a single-cylinder test engine to prepare the gas mixture, and a small amount of fuel is injected directly into the cylinder to ignite the gas-mixture in the condition of a constant engine-speed and a wide open throttle. Also, nitrogen is introduced to the intake air-flow to reduce the oxygen concentration. In particular, effects of oxygen concentration of intake air on combustion process and engine performance are investigated at a wide range of equivalence ratios in various injection timings to clarify the feasibility of EGR. Based on the experimental results, it is shown that EGR enables to exhibit the improvement in brake thermal efficiency and the much decrease in exhaust NOx concentration in the case of earlier injection.

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The effect of injection pressure of diesel fuel on the engine performance in a dual fuel compression ignition engine with natural gas as a main fuel was investigated at low and high engine loads. With increasing in the injection pressure of diesel fuel, the unburned loss decreases and the thermal efficiency improves. In a low load operation, the NOx emissions decrease with increasing in the injection pressures. In a high load operation, lower intake oxygen concentrations with cooled EGR and higher intake pressures with supercharging are necessary to suppress the increases in the NOx emissions and in the maximum rate of pressure rise, maintaining small unburned losses and high thermal efficiencies.

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The spray combustion characteristics of fatty acid methyl ester (FAME) mixed diesel oil were examined experimentally in this study. The FAMEs examined in this study are Methyl Laurate (ML), Methyl Oleate (MO), Methyl Linoleate (MLi) and Methyl Linolenate (MLn), the major components of coconut methyl ester, palm oil methyl ester and rapeseed methyl ester. FAMEs were mixed with diesel oil and injected into a high temperature and high pressure constant volume chamber with two observation windows. The luminous flame formed inside the chamber was photographed by a high speed color video camera and analyzed by a two color pylometry method of luminous flame. From the experiments, it is explored that the ignition delay and the combustion period of FAMEs are almost equivalent with those of diesel oil under the ambient condition of 3 MPa and 985 K. The flame temperature of each FAMEs mixed with diesel oil has only a slight difference. The amount of soot produced decreases with the increase of the mixing rate of FAMEs, which corresponds well with the mass fraction of oxygen content in each fuel.

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Ethanol has the same theoretical air-fuel ratio as DME but has different reactivity. In this study, effect of ethanol blending on ignition and combustion of DME spray was investigated by numerical calculation. As the results, the ignition timing retards and the equivalence ratio in a spray shifted toward lean with ethanol blending. NOx emission decreases when ethanol ratio of 30% or higher because the ignition delay elongates after the end of injection.

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Dimethyl ether is an alternative fuel for diesel cycle engines. In order to understand the spray behavior of DME, it is necessary to know the sound speed, however there is not the reliable value. In this study, we measured the speed of sound in DME in a wide pressure and temperature range of 1-80 MPa, 298-413 K. Sound speed in DME is about 400 m/s slower than that in diesel fuel. Near the critical point, the sound speed decreases remarkably. The measured values are consistent with speed of sound calculated based on BWR equation of state.

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Thermal efficiency and fuel consumption of a Diesel Engine which is main stream of the transportation has to be improved for control of global warming. And a diesel engine is expected to keep the good air quality and health effect, by exhaust emission reduction. Then this paper describes how the variety of Biodiesel Fuel (BDF) and the increase of the BDF mixing ratio reduce CO, HC, smoke and engine-out PN concentration. This paper shows that the PN concentration from the tail pipe is remarkably reduced by after-treatment system.

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As a way of reducing the amount of Paniculate Matter (PM) contained in the exhaust gas, Diesel Particulate filter (DPF) is widely used. To maintain the condition of DPF normal and effective, estimation of the amount of PM deposit accumulated in DPF is very important. Occasionally, the value of pressure drop rises suddenly and it leads to overestimation of the amount of PM deposit. The behavior of PM deposit layer, while the value of pressure drop is increasing, is still unclear. In this paper, we reproduce the sudden pressure increase phenomenon using a commercial diesel engine and a DPF. Several conditions are found to be indispensable to reproduce the phenomenon. The authors also have developed a visualization method to realize the wide-perspective internal observation of DPF. Under the engine operating condition that causes the sudden pressure increase phenomenon, the wide-perspective internal observation experiment has been conducted to clarify the behavior of PM deposit layers in DPF. Off-line experimental result: the image of the DPF observation surface taken after the experiment, indicates that the PM deposit layers have collapsed darling the experiment.

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Numerical studies were carried out for examining the influence of initial velocity and unsteady evaporation of droplets on the group combustion behavior of droplets group. Unsteady evaporation and ignition delay are taken into consideration by solving the transfer equations of heat and mass which govern droplet evaporation and by employing detailed reaction kinetics. Calculation results indicate that giving initial velocity to droplets group change ignition and combustion behavior from symmetric to asymmetric. Droplets on leading edge side strengthen tendency of single droplet combustion with the increase of initial velocity. Though droplets on trailing edge side strengthen the tendency of group combustion for relatively small initial velocity, they strength tendency of single droplet combustion for relatively large initial velocity.

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Dynamic behavior of unburnt diesel sprays under no-evaporation and evaporation conditions were investigated by dual nano-spark shadowgraph photography method. This method enables obtaining two individual high definition shadowgraph images with short photographing interval. Details of temporal behavior can be obtained by comparing these two images. Image analysis was conducted by in-house developed image analysis algorism. As a first step, the raw image was converted into the image that emphasizes the degree of spatial fluctuation. This image shows obvious boundary of the evaporated fuel. This technic can extract not only the outer boundary in the diesel spray, but also the inner boundary between fluctuated region and high density region. In second step, the shapes of extracted boundary on the sprays photographed with certain time interval were compared and the movement of the boundary was calculated. Accordingly, this technic can extract the information of spray dynamic behavior about both of outer and inner boundary of diesel spray. In the present study, the following phenomena were observed. Air entrainment in upstream of the spray was observed only in no-evaporation condition. Spray tip in no-evaporation condition tended to penetrate parallel to the spray axis, instead of the spray tip in evaporation condition expanding wider angle to the axis. Inner core region of the spray moves faster than outer boundary movement.

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The purpose of this study is improvement of spray characteristics of the nozzle, which was developed in this previous study, for a direct injection Diesel engine. The nozzle which was used in this study is that excellent combustion characteristics are obtained by only changing geometric shapes of the multi hole nozzle, that is, inlet and outlet shapes of nozzle holes, hole diameter, hole length and pitch circle diameter of nozzle holes. In this study, effect of geometric shapes of the nozzle developed in this study on atomization characteristics was investigated. As a result, it was cleared that when round inlet and outlet shapes of the nozzle holes were used, atomization characteristics were improved significantly compared with the sharp inlet shape nozzle. Moreover, it was found that in case of the nozzle without hole length of round inlet shape nozzle, breakup length, that is, liquid core length, becomes short about 50 % and spray angle becomes large about 50 % compared with the sharp inlet shape nozzle.

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A laser 2-focus velocimeter (L2F) was used for measurements of velocity and size of droplets in diesel sprays. The L2F had a micro-scale probe which consists of two foci. The data sampling rate of the L2F system was markedly high as 15MHz. Fuel sprays were injected intermittently into the atmosphere by using a common rail injector. The orifice diameter of the injector was 0.112mm and 0.135mm. The rail pressure was set at 135MPa. Measurement positions were located in the plane of 10mm downstream from the exit of the nozzle orifice. The results showed that the size of spray droplets injected from larger orifice was larger than that injected from smaller orifice. The number density of spray droplets injected from larger orifice was lower than that injected from smaller orifice except at the spray center. The number density of spray droplets at the spray center was smaller than at other positions on both injector.

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Measurements of temporal and spatial changes in the velocity and size of droplets of diesel fuel sprays were conducted near the nozzle orifice by a laser 2-focus velocimeter (L2F). The L2F had a high sampling frequency of 15MHz. Fuel sprays were injected intermittently into the atmosphere by using an 8-hole injector nozzle. The diameter of the nozzle orifice was 0.112 mm. The injection pressure was set at 40 and 135MPa. The time interval between injections was 333ms. Measurement positions were located at 10 mm from the nozzle exit. The number of data measured at each position was 40,000. The distance between droplets in the direction of droplets' flight was determined by multiplying the droplet velocity and the time interval between 2 droplets sequentially passing the measurement volume. The measurement result showed that the droplet velocity was the fastest at the center of fuel sprays and the droplet size near the spray center was larger than that at the periphery of fuel sprays. When the injection pressure became higher, the velocity and size of droplets became higher. The number density at the center of fuel sprays was lower than that at the periphery of fuel sprays. It was found that the luminance of spray image became higher with increase of injection pressure.

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This study aims to investigate the spray development process of diesel spray under small-quantity injection condition. The effects of injection pressure and injection quantity on spray tip penetrations were analyzed using a rapid compression and expansion machine, and the effects of injection-rate pattern on spray development process were simulated using a one-dimensional spray model. The results show that the spray tip penetration is dependent on time with exponent more than one just after injection start, and the exponent turns to one and one half as time elapses. With small-quantity spray the exponent is one forth after the end of injection. The simulation results show that the penetration dependence on time to the power of more than one during beginning of injection is caused by increasing momentum flux by rising injection rate, and the penetration rapidly decelerates as reducing momentum flux at the spray tip by decline of injection rate.

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The effect of fuel injection conditions during cranking period on cold startability of DI diesel engine under low-temperature condition was evaluated experimentally. Injection strategy during cranking period was two-stage injection consisting of a pilot injection and a main injection. The main injection timing was fixed at 9 deg. BTDC, and the pilot injection timing was changed from 15 to 35 deg. BTDC. Allocation of injection quantity to the pilot injection and the main injection was changed between 5:95 and 25:75. Dynamic strain of glow plug was measured for evaluation of ignition quality. Cold startability resulting from the ignition quality was good when the pilot injection timing was late and the pilot injection rate was 15-20 %. Furthermore, temporal variation of aldehyde emissions during engine warm-up was obtained. Aldehyde emission was relatively high when the pilot injection timing was 35 deg. BTDC.

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This study investigates influence of fuel injection and ambient gas conditions on lean burn combustion process ignited with diesel fuel. Fuel injection pressure, ambient gas pressure and equivalence ratio were varied in a wide range and influence of those parameters was closely evaluated based on the high speed imaging and the pressure analysis. The result showed that the ignition delay period of diesel fuel was prolonged at high injection pressure and low ambient gas pressure. The initial combustion period was decreased with an increase of the ambient gas pressure when the injection pressure is high.

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Effects of the engine oil on the ignition of iso-octane premixed gas have been investigated using a rapid compression machine. The ignition delay times of the iso-octane premixed gas at an equivalence ratio of 1.0 with or without engine oil in temperature and pressure ranges of 680 - 730 K and 3.0 - 3.8 MPa were measured. The pressure profiles of the iso-octane with the engine oil show a single stage pressure rise over the entire temperature and pressure range, while those of iso-octane show a two-stage pressure rise. We found that there was a line determining the limits of temperature and pressure conditions where the ignition delay times of the iso-octane with engine oil were shorter than those of iso-octane. These results indicate that there are some temperature and pressure conditions in engine cylinder, where the engine oil promote the ignition of the iso-octane premixed gas.

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The oxidation mechanism of gasoline has been investigated using detailed kinetics mechanisms of gasoline surrogate constructed by Mehl et al. and Hashimoto et al.. To validate these mechanisms, the simulated ignition delay times were compared to those of experiments. The mechanism constructed by Hashimoto et al. predicted the experimental results better than that constructed by Mehl et al., which derived from the difference of the reactivity of n-heptane. Although there are some discrepancies between the ignition delay times calculated by the Mehl et al. mechanism and those calculated by Hashimoto et al., it is found that the oxidation mechanism of gasoline is identical.

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A new method for visualization of oil film flow is proposed in this study. We are aiming to visualize oil film by dissolving a photochromic dye in lubricating oil and coloring with UV ray. This paper explains the photochromism of oil and the applicability to measurement of oil film thickness and flow visualization. Firstly, we examined the suitable oil for visualization because the condensation of colored photochromic dye was confirmed in the conventional test oil, PAO. As a result, ester oil, which has relatively high polarity, was obtained as the suitable lubricating oil for visualization. Secondly, we tested this method in the wedge-shaped oil film to quantify oil film thickness. Consequently, it was confirmed that the oil film thickness can be quantified from the absorption of light caused by photochromism. We also confirmed the change of color with time and obtained the relatively long colored lifetime of photochromism. Finally, flow visualization was tried in the flow channel made thickness approximately ten micrometers. The test oil flowing through this flow channel was colored with a third harmonic of Nd-YAG laser. The oil film flow was visualized with the help of image processing.

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A new technic to measure the propagating flame precisely by using densely installed multiple ion-probes has been developed. This system targets the high-intensity and pulsatile combustion, including knocking in gasoline engine, and oscillating combustion in burner or gas turbine combustor. In such environment, observation of details in the combustor by visualization is generally limited because of the strength of observation window. In contrast, ion-probe is physically and thermally strong enough to endure such environment. In the present paper, characteristic features of this measurement technic were investigated by the series of basic tests for measuring the different types of propagating flame with LPG- oxygen-nitrogen mixture. The result shows that this measurement technic has an ability to capture the fluctuation of propagating velocity both in deflagration propagating at a few meters per second and in detonation propagating at supersonic speed with a few kilo meters per second. It is expected that this technic has sufficient performance to capture precisely the knocking in automotive engines and oscillating combustion in burners.

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The development of new energy engine is important to overcome the social problems of global warming and energy crisis. However, in the most recent future, it is important to improve the thermal efficiency of conventional gasoline engine also. As one of the countermeasures, the HCCI combustion applying negative valve overlap (NVO) has been evaluated in the many literatures. So far, we evaluated the normal spark-ignition combustion applying NVO, and we reported the effectiveness to lean limit extension. In this paper, the effectiveness to thermal efficiency is reported.

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CO_2 in exhaust gas from automobile is brought about global warming. In a spark ignition engine, lean combustion brings high thermal efficiency. It becomes difficult to ignite successfully on the other hand. There is a risk of shortening the longevity of the igniter though in it, there is a method of increasing the spark energy as measures. In the study, we proposed the spark plug that installed the flange of dome shaped as the risk measures. This spark plug has aimed at the collection of the shock wave energy generated at the spark discharge and the control of the flow around the spark discharge path. We made dome flanged spark plugs of 3 types. The effect of dome flanged spark plug on the ignition probability using a single cylinder natural gas engine was examined. As a result, it has been understood that the dome flanged spark plug with three holes was effective for the ignition characteristics for wide range of engine speed. (162 words)

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There is a problem to decrease the ignition probability while lean combustion improves that the thermal efficiency of spark ignition engines. Therefore, some techniques that improve the ignition probability are necessary in lean combustion. In the present study, the ignition and combustion characteristics of the spark plug with dome-shaped flanges were examined by using swirling flow fields. The result shows that the dome flanged spark plugs were high ignition probability compared with conventional plug. It is considered the reason was the effect of the collection of the shock wave energy and the effect of suppressing the flow in vicinity of the spark gap. Especially, in lean condition, the ignition probability of the dome flanged spark plug with three holes and the hole was arranged in straight for the flow was the highest. In other side, the combustion characteristic of the dome flanged spark plug with three holes and the hole not to face the flow was better than conventional plug and other dome flanged spark plugs.

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This study investigated the effect of streamer discharge on lean-combustion in an internal combustion engine. A continuous streamer discharge was generated in the wall-side of the combustion chamber of a 2-stroke optically accessible engine that allowed visualization of the entire bore area. The experimental results showed that the weak flame was initiated and grew from the circumference of the electrode under the application of a streamer discharge. As a result, lean-combustion can be made exceed lean-limit of a conventional spark-ignition engine.

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In recent years, Fossil fuel depletion and global warming, air pollution as environmental problems have become big problems. We were focused on plasma assisted combustion for the purpose of high efficiency and reduce environmental impact of the internal combustion engine. The present study had been executed as an experiment on the stage before the plasma assist ignition was applied to a diesel engine. Using a rapid compression machine in the study, we examined the effect of improving the ignition and combustion characteristics of the fuel-air mixture by plasma generated by the micro wave. First of all, the condition that strong plasma is generated was examined in the condition under the high pressure. As a result, it has been understood that the intensity of the plasma was depended on the micro wave frequency. In the plasma assist ignition, it has been understood that the ignition and combustion characteristics are greatly improved compared with a conventional spark ignition. (156 words)

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Hydrogen has been attracting attention as a useful fuel to improve state of environmental pollution and resource depletion by using fossil fuels. In internal combustion engines, which are widely used as conventional technologies, the hydrogen fuel can be applied. Since minimum ignition energy of hydrogen is lower than that of other fuels, the hydrogen fuel tends to cause abnormal combustion. However, the abnormal combustion is easily controlled in a rotary engine. In this study, therefore, a hydrogen rotary engine (HRE) was developed. For improving stability and output power of the 20cc HRE, combustion pressure sensor was adopted to measure combustion pressure in the 20cc HRE. Combustion pressure of the 20cc HRE at high load was decreased with delay of the ignition timing. Maximum torque was 0.24 Nm at BTDC 5 °. Exhaust gas temperature of the 20cc HRE was increased with delay of the ignition timing. On the other hand, thermal efficiency of the 20cc HRE was improved.

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This study aims to investigate if we can use mixtures of biodiesel fuel (BDF) and diethyl ether (DEE) as substitutes for jet engine fuels. The BDF used here was actually derived from waste edible oils. The performance tests were conducted by using a micro gas turbine jet engine for a model plane. The fuels tested were JetA-1 and the BDE/DEE mixtures with DEE-concentrations from 0 to 25 wt%. The present test results show that the thermal efficiency tends to decrease with increasing DEE-concentrations up to 25 wt%, the BDE/DEE mixtures give almost the same thermal efficiency as JetA-1, but they give lower specific fuel consumptions than JetA-1 as a whole.

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The tri-generation system with a diesel engine of heat, electric, and CO_2 has several advantages, including high energy efficiency and reduction of GHG emission by production on green fuel derived from biomass stored CO_2 from engine exhaust. In previous study, we revealed that the aeration of enriched CO_2 is effective to increase algal cell density and algal-oil production in lab experiments. In this study, we demonstrate mass production of algae-oil at enriched CO_2 aeration in cultivation in outdoors experiments. In experiment, the microalgae, Scenedesmus dimorphus, was cultivated in photo bioreactors in greenhouse and two cases of enriched CO_2 aeration; one is a concentration of 10%-CO_2 for 1.5 hours per day and another is 2%-CO_2 for 7.5 hours. And, the influence of starvation state by addition of NaCl on oil production was also investigated. The results show that the aeration of enriched CC_2 for 7.5 hours per day is effective to increase algal cell density. And, the oil content in algae is increased by the starvation stress due to addition of NaCl.

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A unit analysis method using "contact model between the element of a belt for continuously variable transmissions and the pulley sheave" and "the model which considered a gap in the bearing" was contrived. And that was made able to predict tooth contact of a gear correctly. In the conventional model, pulley and the neighboring parts was modeled with one body easily. In the new model, slide pulley and fixed pulley were divided, and oil pressure was set,thereby it was able to express pulley axial bending same as an actual machine.

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In recent years, the power conversion using oil pressure attracts attention as measures against global environment problems. Although a hydraulic motor is effective in oil pressure-power conversion, this is designed for high pressures such as several 10 MPa. So apparatus suitable for the oil pressure-power conversion of low-pressure is needed from now on. Authors made the property evaluation equipment for the power recovery which built into the closed circuit used a slanting axis type hydraulic pump/motor, and performed evaluation examination about the power recovery from the circulating oil of several MPa.

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Recently, necessity of energy saving is more increasing in the industrial field with relation to energy cost increase. Measurement of steam flow rate is indispensable for a performance diagnosis and an energy solution in facilities such as factories and power plants. However, installation of sensor for steam flow is not generally enough. The industrial facilities needs to be out of operation temporarily, in the case of installation of conventional flowmeter such as orifice type and vortex type. Because steam pipes are necessary to be cut for the installation. Accordingly, clamp-on type steam flowmeter, of which installation does not require pipe-cutting, is hoped to be developed. Ultrasonic sensor has certain degree of possibility for steam flow measurement. On the other hand, there are such problems as ultrasonic inlet to a pipe and operational condition of temperature, to be solved. Therefore, we devised "heater method" for steam flow measurement. A circumferential heater is attached to the outside of a tube. Then, axial temperature distribution on the tube outside is measured. Steam velocity is analyzed on the basis of the temperature distribution, considering heat transmission in the pipe. The sensor is heat-resistant and possible to measure high temperature fluid, because it is comprised of the heater, thermocouples and insulator. It is necessary to solve physical phenomenon such as temperature boundary layer and heat transmission in the pipe in case of area heating, to develop the method. This proceeding reports measurement theory confirmation using air and steam flow rate measurement by the heater method.

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