A fully coupled fluid-solid approach for flame spread simulations has been developed using FireFOAM. Radiative heat transfer and soot treatment are fully coupled with the pyrolysis calculations. For gaseous combustion, the newly extended eddy dissipation concept (EDC) for the large eddy simulation (LES) is used. Due to low Reynolds number, the laminar combustion model based on viscous diffusion is presented and coupled with the EDC model. The soot model is based on the laminar smoke point concept recently extended to turbulent fires using the partially stirred reactor (PaSR) concept. For radiation, the finite volume discrete ordinate method (FVDOM) is used with the gaseous absorption coefficients evaluated using the polynomial coefficient of temperature. In the solid region, one dimensional diffusion equation for sensible enthalpy is solved. The effect of in-depth radiation is taken into account using the relatively simple formation according to Beer's law. The Arrhenius type pyrolysis model developed by FM Global is used along with their measurements of the PMMA physical properties as input data. The validation study has been conducted with the published experiment. The predictions are in very good agreement with the relevant experimental data, demonstrating that the present modelling approach can be used to predict upward flame spread over PMMA with reasonable accuracy. Such a fully coupled predictive tool can be used to aid fundamental studies of the flame spread phenomena such as investigating the effects of width, inclination angles and side walls on flame spread.

Experiments have been carried out to develop the food dryness technique by utilization of resonance frequency in the regime of far infrared rays emitting from radiant materials based on the polar crystal metals. The radiant materials developed to realize the resonance frequency with dryness substances have 0.94 in spectrum emissivity ranging from 3 μm to 20 μm in wave length and 180 w/mK in thermal conductivity. The samples used for the study are raw shiitake mushroom, scallop and whiteleg shrimp. The intensity of irradiant energy to food substances is 1.23 W/m² and the energy exchange efficiency is 77.6%. The acquisition obtained from the study are as follows that such food dryness technique using resonance frequency in regime of far infrared rays is very effective for realization of high efficiency dryness so as not lose the effectiveness of umami and flavor. And in addition it is not recognized the appearance of drip substances at any samples.

Cryopreservation technique has attracted special attention from those interested in food shortage in near future. However, because plant is essentially desired to be preserved with living, it is said that cryopreservation of plant is especially difficult. We found the possibility of damage decrease effect under low temperature due to electric current load on plant tissue and reported the results before. This research followed the abovementioned report and investigated the possibility of similar damage decrease effect due to electric current load for the leaf scale-upped from tissue as that of tissue. This research discussed the measure to evaluate the leaf damage due to cold stress using a hyper spectrum camera. As a result, we found new index to evaluate the leaf damage. From the results of new index from spectrum intensity distribution, weight change ratio of leaf before and after the exposure under low temperature, it was clear that there was the possibility of damage decrease under low temperature due to electric current load on leaf.

Dissolved methane concentrations (DM) at 41 lakes along 4 major highways were observed in the open water season in 2008, 2012 and 2013 to estimate diffusive methane flux from lake surfaces to the atmosphere and to verify an enhancive effect of thawing permafrost on the methane flux in Alaska. An inverse relationship between lake size and DM was obtained in lakes in tundra region as was found for the European boreal lakes. It suggests that no evidence indicating an effect of thawing permafrost on DM was found in these lakes in the tundra region at this moment. DM in lakes in the taiga region, however, were higher than those in the tundra region. All lake images on a map larger than 0.001 km² were analyzed and area and number distributions were obtained in order to calculate regional mass fluxes of diffusive methane. Total area of all lakes (807,619) in Alaska (northern region from 59°N) is 49,291 km². Regional summer diffusive flux of methane from lakes in Alaska was estimated to be 77 Gg CH₄ yr^–1. Average diffusive flux density (per lake area) was 1.56 g C m^–2 yr^–1.

Deep metastatic tumor drainage lymph nodes surgical resection leaves behind structural disruptions and associated risks ^(1,2). Hence, there is need for an alternative method with less disruption and risk. We herein report for the first time, the treatment of metastasis by incorporating lymphatic drug delivery system via the lymphatic network ⁽³⁾. Photothermal therapy (PTT) was deployed by combining biocompatible gold nanorods (GNRs) and near-infrared (NIR) laser irradiation using the lymphatic system administration. By controlling the temperature of the target site skin surface via water cooling system, the damage to the skin during the treatment period was avoided. This also allowed precise control over treatment conditions and planning. The results show that this delivery route is very efficient for non-invasive tumor treatment of lymph node metastasis.

Temperatures and gas concentration inside the dewar flask with volume of 20L filled with RDF were monitored to 20 days. Experiments were performed at the dewar flask in aerobic environment (oxygen concentration: 20%) and anaerobic environment (oxygen concentration 0.5%). As a result, the following three conclusions were obtained. (1) The highest temperature in the dewar flask was 77°C in aerobic environment, and 37°C in anaerobic environment. (2) The highest hydrogen concentration in the dewar flask was 3.2% in aerobic environment, and 53% in anaerobic environment. (3) Oxygen concentration has been increasing and decreasing in 1-2 day period in aerobic environment, aerobic and anaerobic environment were interchanged. There result confirm that inside the dewar flask filled with RDF has coexist aerobic and anaerobic environment and they replaced periodically. This conclusion suggest that collaborated action of aerobic and anaerobic bacteria fermentation effects the mechanism of RDF fire.

Recently, prevailing Lithium ion batteries(LiBs), mounted on electric vehicles have the risk of exploding by a fire caused by a collision with a gasoline car. The purpose of this study is to investigate whether commercial LiBs caused fire by external heating, and provide recommendations on the safety of LiBs. In this experiment, we heated the bottom of LiBs which were contained in an aluminum box by a 300 W heater for one hour, to make the battery in an unstable state electrochemically, thereby causing the battery to catch fire by internal short circuit. Also determined was battery voltage, internal battery temperature and heater temperature to observe the voltage behavior to battery temperature while heating. As a result, when the temperature of the battery reached about 80°C, the safety function of the battery operated, and the current was broken automatically. However, a battery fire occurred, which was caused by internal short circuit when the battery temperature reached about 140°C. Therefore, this experiment confirmed that only the safety function mounted on LiBs were unable to prevent battery fire. Moreover, when electric energy remains inside of the LiBs, we confirmed the energy must be released because there is a risk of the battery catching fire to occur again, even after extinguishing it.

Polynomial Chaos Expansion, which is a computationally efficient method for performing uncertainty analysis on large complicated models, is applied to a 2-D turbine blade conjugate heat transfer model, and an uncertainty of blade surface temperature associated with an inlet gas temperature and a TBC thickness is evaluated with 6 model runs. A surrogate model obtained in the polynomial method predicts computational results with great accuracy. It is concluded that the polynomial method is useful for uncertainty quantification of turbine blade temperature estimation.

A Low GWP refrigerant, R-1233zd(E), is low toxicity and non-flammable. And it's GWP value is approx. 1. The specific gas volume is much higher than R-134a, so that, it is not suitable for positive displacement chillers, but suitable for centrifugal chillers. Normal boiling point of R-1233ze(E) is 18.3°C, therefore the pressure in an evaporator of the chiller is lower than atmosphere pressure. In order to keep the performance of the chiller high, air contamination should be the lowest level. So we have developed a very simple air collection system for the centrifugal chiller using R-1233zd(E). In the air collection system, Peltier devices are equipped to condense refrigerant gas to make air concentration high. The performance of air collection system have been measured and evaluated.

With rapid development of electronic devices, their internal heat generation become significantly denser. Accordingly, the thermal management becomes increasingly important for the stable operation. For the heat dissipation performance improvement in limited installation spaces, passive two-phase cooling technique using water is being applied. Instead of water, using refrigerants as the working fluid is advantageous in many aspects. In this study, a gravity-driven cooling circuit using R134a, R1234ze(Z) and R1234ze(E) is experimentally investigated. The experimental circuit successfully kept the heating temperature simulating electronic devices below 80 °C at heat fluxes up to 111 Wcm^-2 and 125 Wcm^-2 with R1234ze(Z) and R1234ze(E), respectively. By using a super-hydrophilic boiling surface, the heat flux was extended to 133 and 135 W cm^-2 in R1234ze(Z) and R1234ze(E). The experiment demonstrated that using the refrigerant and super-hydrophilic surfaces could be a beneficial solution for electronic device cooling.

Cooling capacity and COP of an adsorbent chiller using low heat capacity adsorber were estimated by a simulation of silica-gel/water pair adsorption refrigeration cycle. In the simulation, various operating parameters which were temperature and flow rate of the external fluids such as heating, cooling and chilled water, heat transfer conductance of evaporator and condenser and switching time of the adsorption/desorption process were given as the boundary conditions. As the result, it seemed that the influence of external fluid conditions on the capacity and COP was same one as seen in a conventional cycle. However, because of the improvement of adsorption rate, an enhancement of the conductance in the evaporator and condenser, and shortening the switching time increased the capacity effectively. Then, the appropriate operating conditions for the chiller were clarified. Finally, it was estimated that the capacity and COP of the chiller with low heat capacity adsorber were up to two times as large as those of a commercial FAM-Z02/water pair adsorption chiller with conventional one.

Experiments have been carried out to examine the fundamental characteristics of radiation cooling of new radiant materials developed for the study based on the polar crystal metals. In addition, the basic performance for the radiation cooling of LED lamp and LED fluorescent light haven been also investigated using the new radiant materials. The acquisition obtained for the studies shows that the radiation effect of new radian materials is superior to those of existent radiation paints such as alumite and high efficiency heat radiation paints. And the rate of temperature drop of diode on LED lamp and LED fluorescent light can be estimated as 10%. Where, the new radiant materials are produced by mixing nano-size crystal metals into high efficiency heat radiation paints. This concept is caused by the increase of surface area due to the rough surface generated by nano-size crystal metals.

There are several methods for heat transfer enhancement. For example, one can attach various fins on the heat transfer surface, process the surface roughly, insert twisted tape, and so on. These methods increase the heat transfer coefficient or area by manufacturing changes to the heat transfer surface. However, it is necessary to consider the problem on account of processing heat transfer area. In the previous study, heat transfer and flow characteristics performances of air-water heat exchanger by under the condition inserting metallic wire was evaluated. By the increase of porosity, although heat removal amount is slightly reduced, the pressure drop was found to be greatly reduced. On the numerical analysis, it was to evaluate the validity of the analysis model. The metal thin wire having a square cross section by inserting the flow path in the flow path in a mesh lattice pattern, it is possible to simulate the experimental results, it is possible qualitative assessment.

Ignition limits (limiting current value) of insulated electric wire with continuous current supply under microgravity was studied with numerical method. From previous study, we mentioned that results of ignition limits obtained by microgravity experiments are limited by microgravity period (20 s). Then in present work, we conducted numerical analysis to find limiting current values without the effect of microgravity period. As a result, a limiting current value by numerical calculation are lower than that by microgravity experiments. In addition to that, we discussed a mechanism to decide limiting current values with numerical analysis. Results of numerical analysis indicated that limiting current values could be determined by exhaustion of insulation. After all of the insulation was thermally decomposed and gasified, air which was removed near the wire surface by fuel gas diffused back towards wire surface. This leaded to increase in heat release rate near the wire surface. On the other hand, such inflow of air removes fuel gas from near the surface. When current value was higher than a limiting current value, heat release rate can increase enough to cause ignition even though fuel concentration near the wire surface decreased. Thus it was mentioned a possibility that amount of insulation, which controlled air diffusing, could decide limiting current values. Therefore, numerical calculation for thicker insulation cases were also conducted. The numerical results showed thicker insulation caused ignition with lower current values. This indicated that ignition limits could be dominated by thickness of insulation.

Recently, CFD is used on a heat exchanger's design for cutting cost. A constant temperature treatment for boundary condition using design process of a heat exchanger is often imposed on a heated or cooled wall. In the case of caluculating heat conduction of metal, harmonic mean is applied for valuation of heat conduction between fluid and solid. In this study, boundary condition is applied not the harmonic mean of thermal conductivity but the way of calculating thewall temperature for an improvement in analytical accuracy.

A novel heat exchanger using parallel small refrigerant channels has recently been developed for air conditioning systems. Boiling flow in parallel channels is, however, subject to unstable flows. The unstable flows trigger dryout even under low time-averaged quality conditions and result in deterioration of heat transfer capacity of the heat exchanger. The authors developed a simulation model which predicts heat transfer capacity of the parallel channel heat exchanger under unstable boiling flows. In this paper, to confirm applicability of the model, the simulation results for pressure drop oscillation and density wave oscillation in a single channel tube were presented and compared with the conventional experiments. The simulation model reproduced well the periodical changes of mass flow rate and pressure drop in the pressure drop oscillation and stability boundary for the density wave oscillation.

To investigate the forced-oscillation-frequency responses on the three-dimensional thermal convection inside a cube heated from one wall and chilled from its opposite wall in the non-gravitational field, the authors conduct computations at Plandtl number Pr = 7.1 (water). The direction of the forced sinusoidal oscillation is parallel to the temperature gradient inside the cube. As a result, five kinds of flow structures S2, S4, S5, S6 and Sα appear in the tested ranges of vibrational Rayleigh number Raη and non-dimensional forced-oscillation frequency ω. The Sα consists of a pair of trident currents. Whenever it is not conductive but convective for ω < 5.0×10², convective motion always starts with the S4 from the rest at each forcing cycle. The authors find out the optimum frequency where the amplitude of a spatially-averaged kinetic energy attains the maximum at each Ra_η. At the optimum frequency, flow structure is always characterised by the S4. So, the optimum frequency can be related with the S4.

Forced convective heat transfer from a single row of cylinders placed in the longitudinal and the transverse direction to the flow was investigated experimentally. The average Nusselt numbers from the longitudinal row of six-cylinders were first measured in the range of Reynolds numbers Re_d =160-2000 and the spacing between cylinders G =5-70mm, where the cylinder diameter d were varied as d=8.4 and 14.4mm. Similar measurements were also carried out for the transverse row of multiple cylinders. It is found that the average Nusselt numbers Nu_G are well correlated with the non-dimensional parameter Re_G (G/d) for both cases of the longitudinal and transverse row of cylinders, where Nu_G and Re_G stand for the Nusselt and Reynolds numbers based on the cylinder spacing.

In a highly rotating electric motor, spatial and temporal harmonics in the magnetic field generate a vast amount of heat in the rotor. Fast elimination of this heat from the rotor is the key factor for designing the electric motor. In order to simulate the heat transfer of the motor rotor, we have built a thermal network model of highly rotating concentric cylinders and set up the test equipment. Measurement of the flow condition and the resulting Nusselt number of the narrow gap between the two cylinders validate our heat transfer model. This model gives us a swift and simple calculation tool for designing a highly rotating electric motor.

Three-dimentional numerical analysis was conducted on the natural convection heat transfer of nanofluids under microgravity environment with G-jitter. G-jitter is modeled with sinusoidal oscillation of gravity, and the residual gravity and amplitude are the same as 10^-3 G. Nanofluids is a suspension composed of water and Cu nanoparticles. Shallow rectangular chamber is filled with a nanofluids. The bottom wall is heated and the top wall is cooled, and the periodic boundary condition is applied to other boundaries. Rayleigh number is 3×10⁶, volume fraction of suspensions are 0, 0.01 and 0.05. The findings obtaind are summarized as follows: Thermal plume is observed in the chamber, and thermal convection repeats occurrence and disappearance to follow the gravity modulation. The local heat transfer rate increases at the bottom wall where downward flow collides. Convective heat transfer decreases with increasing volume fraction since viscosity of nanofluids is increased. When the volume fraction was 0.01, heat transfer characteristic is the best in a parameter of this analysis.

Experimental observations on the trigger mechanisms for the departure from nucleate boiling in subcooled flow boiling in a vertical, single-tube with an inner diameter of 4 mm and heated length of 5 mm are presented. In this study, a transparent heated tube is used. The tube is made of Pylex glass which inner wall is covered with extremely thin gold film, and it can be measured the inner wall temperature and observated flow behaviour simulataniously. Experiments used FC-72 as a test fluid are counducted under the conditions of G=400-1000 kg/m²s, ΔT_sub=30 K, q_in=464-673 kW/m². Three indicators, dry patch area, three-phase interfacial length and two-dimensional projected gas-liquid interfacial area (2D-PGIA) are drived from high-speed images. 2D-PGIA that is proposed in this study is a new indicatior, it can be considerd as a simple expression of interfacial area concentarion. The results indicate the possibility that the reduction of 2D-PGIA at constant heat flux condition is the trigger of DNB.

We previously found residual water after the complete evaporation of volatile droplets such as organic solvents, which was considered to be condensed from ambient onto the droplet interface. Since evaporation of these liquids into moist environments is ubiquitous, the understanding of the influence of surrounding moisture on evaporation process is necessary. In this work, we measure the amount of condensed water at different stages of ethanol droplet evaporation in controlled environments by means of gas chromatography. Preliminary experiments show an increase in the amount of condensed water as relative humidity rises. We also propose an enhancement of ethanol evaporation probably due to the heat of condensation.

It is important and required for chemical analysis/synthesis using microfluidic channels to visualize diffusion phenomena and chemical reactions. We have thus developed a near-infrared (NIR) absorption imaging method to simultaneously measure the temperature and concentration distributions of aqueous solutions. This method is based on the fact that the ν₂ + ν₃ absorption band of water in an NIR region shifts to shorter wavelength as the temperature increases and that the band is very sensitive to the mole fraction of water. This paper shows the temperature and concentration images of aqueous solutions of methanol, ethanol, and glucose flowing in a Y-shaped microchannel. From the concentration images, the diffusion coefficient of each solute in water is determined by using a fitting function based on a one-dimensional diffusion equation, and its temperature dependence is quantitatively discussed.

We studied a flow phenomenon of liquid into a trench with or without gas during a filling-trench process in semiconductor manufacturing. The flow was calculated using a particle method. Our goal is to find the best condition to fill trench in minimum time. Effects of parameters such as surface tension, dynamic viscosity, and initial liquid film thickness were obtained. We also calculated the flow into a micro trench.

The transient three-dimensional numerical computations are carried out to clarify natural convective heat transfer characteristics of Al₂O₃-water nanofluids in a vertical cylindrical enclosure heated from below and cooled from above. Thermophysical properties of Al₂O₃-water nanofluids such as density, specific heat capacity, thermal expansion coefficient, viscosity, and thermal conductivity are estimated by the conventional prediction equations. Computed average Nusselt numbers of natural convection of Al₂O₃-water nanofluids decreased with the increase of the particle volume fraction compared to that of water. On the other hand, computed convective heat transfer rates of Al₂O₃-water nanofluids increased with the increase of the particle volume fraction compared to that of water. The increase of the convective heat transfer rates disagrees with the experimental results reported by Li and Peterson. Therefore, the natural convection computed by using the thermophysical properties of Al₂O₃-water nanofluids estimated with the conventional prediction equations cannot describe the heat transfer characteristics of nanofluids accurately.

Measurements of temporal changes in the velocity 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 0.101 mm. The injection pressure was set at 80MPa. The time interval between injections was 333ms. Measurement positions were located at 10 mm from the nozzle exit. The number of data measured was 40,000. Turbulence intensity of droplet velosity was determined as relative standard deviation of velocity. Spray width was evaluated by high-speed images of spray. The measurement result showed that there was a strong negative correlation between droplet turbulence intensity and spray width.

Spray characteristics and vaporization characteristics of diesel fuel spray were experimentally measured in a constant-volume chamber. A single-hole solenoid injector was used, which can achieve super high injection pressure, that is, 350 MPa. Spray angle and spray tip penetration were measured in room-temperature ambient gas. Vapor-phase and liquid-phase penetrations were measured in hot ambient gas. The effect of fuel injection pressure was examined up to 350 MPa. The spray angle increased with increasing injection pressure. The effect of injection pressure on the spray tip penetration were reproducible by the conventional theory. Enhancement of fuel vaporization by increasing injection pressure was qualitatively.

In order to investigate the phase changing phenomena of Diesel fuel, the critical locus curve of nitrogen-tridecane mixing system was estimated. The result shows that the critical pressure of the mixture indicate a strongly non-linear curve and its peak value is more than 10 times larger than the in-cylinder pressure at the end of compression stroke. Furthermore, we investigated the effect of atmospheric condition in an engine cylinder on the gas-liquid phase-changing process of a fuel-air mixture. The phase change condition from liquid to gas of the mixture was determined with comparing the adiabatic mixing temperature to the dew point temperature obtained from vapor-liquid equilibrium calculation.

Effects of ambient temperature and density on combustion of diesel spray under high temperature and high pressure ambient were experimentally examined using a constant volume chamber of 60cc that simulates the combustion chamber of automobile diesel engine. It is confirmed that the ambient temperature and pressure has large effect on the shape of heat release rate, the ignition delay and the combustion duration. As the increase of ambient density and as the increase of ambient temperature, the ignition delay becomes shorter. In comparing with the results of 800cc combustion vessel, ignition delay shows the difference in the low ambient temperature range.

Effects of fuel injection duration and ambient conditions on ignition and combustion characteristics of diesel spray in a high temperature and high pressure vessel was experimentally examined using single hole nozzle. The fuel injection duration was changed from 0.4ms to 1.2ms. The ambient temperature was changed from 860K to 985K. The ambient density was 15kg/m³. The flame temperature and the KL factor were quantified through an image analysis technique using two-color method. From the experiments, it is confirmed that, the injection duration has little effects on ignition delay and flame temperature at initial stage. As the decrease of ambient temperature, the ignition delay becomes longer and the flame temperature becomes lower. From the discussion of the 1D KL factor distribution, it is confirmed that the soot production at the head vortex region and that at the quasi-steady region have to be discussed separately. From the discussion of total KL factor it is confirmed that, as injection duration increased, soot production at the quasi-steady region increased proportionally.

In order to improve the pour point and smoke emission of coconut oil biodiesel, coconut oil isobutyl ester, trans-esterified from isobutanol and coconut oil, was mixed with isobutanol, and the fuel properties, combustion characteristics and exhaust emissions of the blend fuel were investigated using a single cylinder DI diesel engine. Coconut oil isobutyl ester with 30 mass% isobutanol (CIBE-IB30) has lower pour point (-20 °C) compared to coconut oil 1-butyl ester with 30 mass% 1-butanol (CBE-B30). The ignition delay of CIBE-IB30 is slightly longer than that of CBE-B30. Therefore, especially at low load conditions HC and CO emissions of CIBE-IB30 are higher than that of CBE-B30. However, CIBE-IB30 has almost the same thermal efficiency and NOx and Smoke emissions compared to CBE-B30 at all load conditions. From the experimental results of pour point, thermal efficiency and exhaust emissions, it is concluded that CIBE-IB30 is better alternative diesel fuel than CBE-B30.

This study aims at improving exhaust emissions and thermal efficiencies in a natural-gas engine with diesel-fuel pilot injection. Performances and exhaust emissions were measured for various pilot injection conditions under a supercharged condition using a single cylinder small-bore test engine. Two-stage pilot injection was examined varying first/second pilot injection timings and quantities. The results show that two-stage injection offers lower NOx and HC emissions, while the available range of equivalence ratio is restricted. Advanced second injection lowers NOx emission, while it increases HC emission for a fixed BMEP. The smaller amount of second injection is preferable for lower NOx; however, the available range of equivalence ratio is narrower.

In order to search an injection strategy for partially PCCI combustion implementing low NOx, low smoke, and low maximum pressure rise rate, a series of experiment was carried out using a single-cylinder diesel engine equipped with a dual injector system (DIS), which includes two sets of common-rail injection system. The DIS enables variable injection rate for each injection pulse and a wide-range dwell between injection pulses, including even negative injection dwell. The baseline injection strategy was three-stage equally divided injection. The effects of injection timings, ratio of injection quantities, and second-injection pressure were investigated under a condition of constant speed, constant load, and constant NOx emission concentration. The results show that significant reduction of smoke emission was obtained by using the three-stage equally divided injection, while maximum pressure rise rate increased. A combination of increasing second-injection quantity, reducing third-injection quantity, and lowered second-injection pressure reduced the maximum pressure rise rate, keeping thermal efficiency and low smoke emission.

Formaldehyde (HCHO) is an important intermediate species in the oxidation of fuel, whose concentrations contribute to the construction of the detailed chemical kinetic model of fuel oxidation. In this study, HCHO in a dimethyl ether (DME)-premixed flame under atmospheric pressure was quantified using 2f-wavelength modulation spectroscopy (2fWMS) and a mid-infrared interband cascade laser (mid-IR ICL). 2f-WMS spectrum of HCHO in the DME-premixed flame was obtained and HCHO concentration was measured in terms of the peak intensity of the 2f-WMS spectrum. The concentration distribution of HCHO in the DME-premixed flame was also obtained using the HCHO concentration measured by the mid-IR ICL and an Abel conversion.

In this study, the influence of coexisting lower alkanes on n-heptane HCCI combustion was experimentally investigated. The experiments to compare n-heptane/methane HCCI and n-heptane/propane HCCI were carried out using a single cylinder HCCI engine. As the result, the low temperature reaction was more suppressed and the start timing of high temperature oxidation reaction was delayed in n-heptane/propane HCCI than in n-heptane/methane HCCI, though the octane number of propane was lower than that of methane. This inconsistency with octane rating was explained by numerical analyses on the basis of detailed kinetic mechanism that propane consumed more OH radicals as the chain carrier of low temperature oxidation mechanism since propane had higher reactivity with OH radical than methane.

To examine new fuel's ignition delay time, a simpler experimental method other than a shock tube or a rapid compression machine is required. In this study, a new method to estimate ignition delay time combining a micro flow reactor and the Livengood-Wu integral is proposed. Using a micro flow reactor, which has a steady temperature distribution by an external heat source, the steady ignition point for premixed gas under constant pressure is obtained. Then, the temperature history that the premixed gas had experienced before it ignites can be calculated. Based on the Livengood-Wu integral and the temperature history, the coefficient and the activation energy for the Arrhenius type ignition delay model was obtained. Finally, the ignition delay time for the lean methane-air premixed gas is predicted using ignition point and temperature history. However, the predictions were quite different from other researches because the actual temperature history might be changed from the temperature history obtained before ignition for normal flame with heat release from its combustion. But for weak flame with less heat release, more accurate value was obtained.

Heat efficiency is improved by making a lean burn in a spark ignition engine, but on the other hand, it brings on problems that ignition probability falls into misfire and/or decreases effective work due to the downslide of flame propagation. It is important to make lean burn succeed in strong turbulence field to avert these problems. In the present study, the ignition and combustion characteristics of the spark plug with dome-shaped flanges that has some holes for exchanging gas 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 mixture condition, the ignition probability of the dome flanged spark plug with three holes was the highest. The combustion characteristics of dome flanged spark plug that has 2.4mm holes was better than conventional and other dome flanged spark plugs. Furthermore, when the direction of the hole was set up in the direction where a flow is introduced, combustion characteristic was improved.

Influences of flame temperature on knock occurrence process in a constant volume vessel were investigated in this study. Flame temperature was varied by Ar dilution to the mixture. Mixture composition was determined so that adiabatic compressed temperature of end gas was almost constant. Cool and blue flames were observed in front of the propagating flame before the occurrence of pressure oscillation at all of the experimental conditions. Knock occurrence process may be sensitive to temperature distribution in the end gas which is affected by heating near the flame and cooling at the chamber wall. Then unsteady 1D numerical simulation using detailed reaction mechanism was carried out in order to investigate the temperature distribution in the end gas. The occurrence of cool and blue flames observed before the knock occurrence might be affected by temperature distribution in the end gas.

The effects of hydrothermal aging on a Cu-ZSM-5 SCR/DPF catalyst were investigated to understand the aging mechanism of an SCR catalyst coated on DPF. NOx conversion and NOx oxidation efficiencies were obtained for the hydrothermally aged SCR/DPF catalyst. NOx conversion ratio provided by the standard SCR reaction is more sensitive to hydrothermal aging than that provided by the fast SCR reaction. NOx conversion efficiency of the deteriorated catalyst at 500 °C was higher than that of the fresh catalyst. NO and NH₃ oxidation efficiencies and NH₃ and NO₂ storage capacities decreased after hydrothermal aging.

It has been reported that a fraction of the ash generated by an engine can slip through the diesel particulate filter (DPF), causing malfunctioning of the OBD. To investigate the mechanism of this ash slip, repeated experiments are necessary. However, ash formation in an engine is very slow. In this study, a stable and accelerated ash generation system was constructed using a diffusion flame burner. Ash samples were analyzed by HPLC, XRD, and SEM-EDX. The produced ash contained CaSO₄, CaS, Ca₃(PO₄)₂, Ca₅(PO₄)₃(OH), CaO, ZnS, and ZnO, and had particle sizes of approximately 1 - 10 μm. These characteristics are similar to those of the ash generated by an engine system, which indicate that the system constructed using a diffusion flame burner can generate ash comparable to that generated by an engine.

Thermal efficiency and fuel consumption of a diesel engine which is main stream of the transportation has been improved for control of global warming. And a diesel engine is expected to keep the good air quality and the health effect, by exhaust emission reduction. In this research, the influence of fuels, diesel fuels and BDF(Bio-diesel fuel), and EGR on the exhaust emission and nano-particle exhausted the diesel engine were investigated in detail. This paper describes that BDF also is very effective to reduce the exhaust emissions and nano-particle in condition with EGR.

The internal combustion engine encounters the cavitation erosion induced by piston slap. The impact vibration between the piston and cylinder liner generates the pressure fluctuation on the coolant side of the liner and leads to occur the cavitation in the case that dynamic pressure falls below its vapor pressure. Authors have already developed the analytical method to predict the liner vibration caused by the piston slap. In this paper, the acoustic characteristic of the water coolant passage of the actual diesel engine in vacuum condition is analyzed and compared with the measured result. Then, theoretical method to determine the coupled vibratory characteristics of structure and water acoustic field is developed. This method employs modal analysis technique and Finite Element Method. Calculated results of vibro-acoustic characteristics of the engine block and the water coolant passage are compared with the measured ones. Water pressure in the water coolant passage at the running condition is calculated and the possibility of the liner cavitation occurrence is discussed.

Some energy is lost from an operating machine by all means. In this research, the energy that is lost by the intention of the manipulator of the machine is defined as the artificially discarded energy. Then a way to recover the artificially discarded energy from an operating machine as the potential energy is discussed. In this paper, the basic mechanism to recover the kinetic energy of a vehicle reducing speed by braking as the potential energy into a spiral spring was proposed and the prototype of it was made. The preserved energy in the spiral spring will be regenerated as the kinetic energy again of the vehicle when the vehicle begins moving. The flow of the energy is shown and the recovery efficiency and the regeneration efficiency are discussed by some basic experiments.

In order to establish a monitoring method for clinker deposits during the operation of pulverized coal-fired boilers, we have been developing a monitoring technology by using strain gauges and a thermal image camera which is not affected by flames and ash particles. We removed the influence of temperature fluctuation and vibration from strain gauge data and applied the specific medium infrared rays as the measurement wavelength in the observation by the thermal image camera. As a result, the changes of the clinker weight and the clinker distributions on the panels have been monitored successfully.

Power generation in isolated areas is a difficult challenge. Isolated areas usually rely on diesel engines to generate electricity, but fuel transport costs and global oil availability threaten the energy security for these areas. Although solar and wind energy have been regarded as a solution, their inherently variable output require high capacity energy storage systems to provide a stable power output. Recent advances in hydrogen technology allow us to consider hydrogen fuel as a viable energy storage/supply method. In this study, a hydrogen fueled micro-grid for isolated areas is proposed. This optimal model is designed to minimize the objective function by finding the optimum number of residences, the size of the facility, and the capacity for each component of the grid. As a result of the analysis, the proposing grid has environmental and economic advantages in compared the conventional system.