In rapid thermal processing of a semiconductor wafer, keeping a given temperature rising speed of the wafer during the heating process is very important. We calculated the effect of various heating control methods on the error of the temperature rising speed of the wafer. We calculated the PID control, the control by correcting with temperature rising speed, the control with a thermal model, the control with a prepared relation, and the combined method. We found that the combined method with a thermal model and rising speed is a good method to decrease the error of the temperature rising speed. The minimum error of the temperature rising speed at 700°C is less than 0.1°C/s during the temperature rising process of 100°C/s and the monitoring time step of 0.05s. We calculated the effects of control-delay-time and measuring error of the monitoring temperature on the error of the temperature rising speed.

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A Solid Oxide Fuel Cell (SOFC) with flat-tubular structure was successfully fabricated by ceramic wet processing. The SOFCs had 3 channels or 4 channels for fuel gas flow inside and were supported by the fuel-electrode. The SOFCs were composed of 8 mol Y₂O₃-ZrO₂ (YSZ) electrolyte, Ni-YSZ fuel-electrode and La_0.8 Sr_0.2 MnO₃ air-electrode. The SOFCs had a feature that fuel gas was homogeneously supplied to fuel-electrodes with fuel gas pipes made of heat-resistant alloy. The SOFC of 50 cm² active area was operated to achieve maximum power density of 0.23 W/cm² at1000°C. The effect of the fuel gas pipe on the cell performance was recognized, because the performance was two times as high as that of SOFC without the fuel gas pipe. The performance of the SOFC with 4 channels for fuel gas was slightly higher than that with 3 channels. It also appeared that the performance of SOFC with 3 channels was decreased rapidly with increasing fuel utilization.

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Local flow measurements were performed for vertical upward bubbly flows in a 9 mm-diameter pipe at normal- and micro-gravity conditions. A stereo image-processing method was used for measuring void fraction profile, interfacial area concentration and Sauter mean diameter. The flow measurements were performed at four axial locations (axial distance from the inlet normalized by the pipe diameter, z/D=5, 20, 40 and 60) at various flow conditions of superficial gas velocity (0.00840-0.0298 m/s) and superficial liquid velocity (0.138-0.914 m/s). By taking into account the normalized parameters on void peak fraction and void peak intensity in pipe cross-section, the phase distribution pattern was quantitatively-classified into three patterns : a wall peak, a core peak and an intermediate peak. The phase distribution pattern maps were newly presented for vertical upward bubbly flows at normal-and micro-gravity conditions.

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A solid-liquid two-phase mixture (water and aluminum particles) was vertically led to a T-junction. Particle number densities (number of particles per volume) at the outlets were measured at inlet concentrations of (1.7-9.2) ×10^-3%, Reynolds number ranging from 12000 to 19000, and Stokes number of 0.45 to 4.3. As a result, we found a velocity ratio (branch velocity/inlet velocity) range where solid particles did not enter the branch of the T-junction with the vertical orientation. The present data at lower inlet concentrations was compared with those obtained by Nasr-El-Din at higher inlet concentrations, i.e., 3 to 26%. We found that dimensionless concentrations at the branch (the present data) were higher than those obtained by Nasr-El-Din. Our dimensionless particle number density at the branch for the T-junction with the vertical orientation was found to be higher than those with the horizontal T-junction at similar inlet concentrations.

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Jets issuing through small holes in a wall into a freestream have proven effective in the control of boundary layer separation. Longitudinal vortices are produced by the interaction between the jets and the freestream, and this technique is known as the vortex generator jet (VGJs) method. In the case of VGJs with circular orifices, the jets are pitched at an angle of 45 deg or less to the wall for the effective suppression. However, a small jet pitch angle causes the complex operations in manufacture process of the jet orifice installed in the practical devices. In this study, the VGJs with T-shaped jet orifices were practically applied to flow separation control of a two-dimensional diffuser, and the suppression effect for the T-shaped orifice was compared to that for the circular orifice in the case of a large jet pitch angle (60 deg). The T-shaped orifices produce the counter-rotating vortex pair which has the different strength between positive and negative vortices, and the longitudinal vortices exist near the lower wall. Therefore, the VGJs with T-shaped orifices provide more effective momentum transfer to the boundary layer and make the separation control effective, in contrast to the VGJs with circular orifices.

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Flow around a circular cone mounted on a flat plate has investigated with flow visualization in a thin laminar boundary layer. The apex angle of circular cone is in the range of 2α?90° and the height H is 50 mm. Then, the Reynolds number based on the height of the circular cone is 1010 and the relative boundary layer height δ/H is almost 0.41. The flow visualization was conducted by means of a dye injection. Necklace vortices (Primary and secondary vortices) are formed around the circular cone. The front stagnation height Y _s, which is a representative length scale of the necklace vortex, tends to increase with 2α less than 2α?45°. The streak lines at topside of the front stagnation height have a curvature near the circular cone and the curvature increases with 2α. From pressure gradients in the neighborhood of the stagnation point, semi-empirical formula on Y_s/H was proposed as a function of a and δ/H. The formula is well consistent with the data of the present flow visualization and other researchers.

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The effect of viscosity of the liquid phase on the averaged liquid velocity field in front of, around and behind the large bubble rising in stagnant liquid in a circular pipe of inner diameter D=40.0 mm is measured. Ultrasonic Velocity Profile monitor (UVP) is used to measure the velocity field. The instrumentation and measurement method are similar to those the authors have presented in the previous paper⁽²⁾. Five kinds of silicone oil whose kinetic viscosities cover 102-8 946 mm²/s and water are used as the liquid phase. In the liquid phase in front of the large bubble, the magnitude of small upward velocities decreases with increasing the kinetic viscosity. In the liquid film around the large bubble, the downward acceleration is small when compared with water. The maximum downward velocity in the film soon becomes a constant value of bubble rising velocity approximately if the kinetic viscosities are larger than 330 mm²/s. In the wake behind the bubble tail, a large ring vortex, which appeared when water is used, is not recognized for the silicone oil.

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Experimental studies of a turbulent flowfield developing over the heated riblet surface were carried out in a low-speed wind tunnel. The instantaneous velocity fields were measured by using a particle image velocimetry (PIV) in a plane that was parallel to the riblet surface, and compared with those over a heated smooth surface. The reduction ratio of the skin friction coefficient over the heated riblet surface reached up to 8% for the riblet spacing of about 13 viscous wall units. This is almost the same spacing as that obtained for the non-heated condition. The streamwise and wall-normal turbulent intensities against the local time-mean velocity were decreased in their peak values for the heated riblet. The instantaneous fluctuating velocity fields obtained by subtracting the ensemble-averaged velocity from instantaneous velocity vectors revealed that the appearance of a lowspeed streaky structure became more intermittent over the riblet surface. This fact suggested a reduction in turbulence production in the near-wall region. Furthermore, it was also found that a perturbation of the spanwise velocity fluctuation was restricted near the riblet surface.

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The effects of a turbulence-generating grid on fluid mixing and chemical reaction in a liquid sheared mixing layer were experimentally investigated. The grid was installed at various positions in a mixing layer. Instantaneous velocity and concentration were simultaneously measured using a laser-Doppler velocimeter and a laser-induced fluorescence method. The results show that the grid generates turbulence at small scales and enhances fluid mixing and chemical reaction, but it decreases the velocity gradient in a mixing layer and the decrease of the velocity gradient results in the decrease of turbulence intensity and vertical mass transfer. Whereas the former influence appears only in the near region of the grid, the latter influence remains in the downstream region of the grid. Consequently, fluid mixing and chemical reaction are more promoted in the case which the grid is installed in the developed mixing layer than those in the cases which the grid is installed in the transitioning mixing layer.

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It is well known that all positive displacement pumps generate a flow pulsation which interacts with the system to produce a pressure pulsation. This pressure pulsation is a periodic function of time with a fundamental frequency and higher harmonics. Therefore, if the change of pump rotational speed in the operation cycle is not large such as in a hydraulic excavator, folk lift, an injection molding machine, etc., the harmonic frequencies of pressure pulsation would be almost fixed. For these kinds of hydraulic systems, a quarter wavelength side branch has been widely used for attenuating the pressure pulsation. In this paper, an effective design method for the insertion of the quarter wavelength side branch is described. An optimum design calculation used in this study searches the design parameters such as lengths and an insertion position of the side branch by taking account of wave propagation characteristics of the all circuit elements. The design results were examined by both the theoretical calculation and the experimental results, and the designed side branch showed good attenuation performance in the certain hydraulic circuit.

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In recent years, the wind turbines have been installed actively and the suitable sites of wind farm have been decreased on land. On the other hand, a lot of wind energy resources are latent and it is expected that wind power will be installed in the future on the sea. This study aims to establish a measurement method of wind characteristics using a small ship for decision of suitable site for offshore wind power. We constructed the wind measurement system, which is composed of an ultrasonic anemometer, a differential GPS (DGPS) and an inertial measurement unit. The system was installed to a small ship and wind characteristics at 10 m height above the sea surface were measured by an ultrasonic anemometer on the Sea of Japan close to Tottori prefecture. Raw data of the wind velocity obtained in the proposed method includes the error caused by the pitching, rolling and yawing of the ship. In this study, the raw data of wind velocity was corrected by the data of the DGPS and the inertial measurement unit. Conclusively, the raw wind velocity contaminated by the oscillation and cruising of the ship was corrected and the wind velocity maps were obtained.

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An application of contra-rotating rotors, in which a rear rotor is employed in tandem with a front one and these rotors rotate in the opposite direction each other, has been proposed against a demand for developing higher specific speed axial flow pump. The most important feature of contra-rotating axial flow pump is that the rear rotor, installed instead of the stator of conventional type, plays a role not only to recover the static head but also to give the energy to the fluid directly. Then, the rotational speed or the pump size could be reduced with the same design specifications of pump head and flow rate as those of the conventional type. As another advantage, contra-rotating rotor theoretically yields a stable head-characteristic curve with a negative slope. In actual performance test of contra-rotating axial flow pump, a positive slope of head-characteristic curve, however, appears at the partial flow rate, which seems to be in the same manner to conventional type, depending on the rotors design. In the present study, in order to investigate the flow mechanism of head deterioration at the partial flow rate, blade-to-blade velocity distributions around the rear rotor have been measured with Laser Doppler Velocimetry (LDV) in the partial flow rate conditions by ensemble averaging technique with the rotating position of the rear rotor. Flow distributions in the tip region of rear rotor at flow rates just before and after the head deterioration are compared and the flow mechanism of head deterioration is discussed with the help of static head distribution on the casing wall.

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Motions of tracer particles enclosed in a tank-treading lipid bilayer vesicle have been observed by phase contrast microscopy. Giant vesicles were swollen from 1, 2-dioleoyl-sn-glycero-3-phosphocholine with hydration water containing polysterene particles by the gentle hydration method. Using the simple shear flow apparatus shown in our previous report [Hatakenaka, Takagi and Matsumoto, Trans. JSME, Series B, Vol. 74, 530 (2008)], we analyzed motions of particles in a tank-treading vesicle relative to the center of mass of the vesicle. In our observation, the particles move along the ellipsoidal orbits, which are homothetic to the vesicle shape. It is shown that angular velocities of the particles near the membrane change periodically, and agree quantitatively with the experimental result on a motion of a particle adhering to the membrane of a tank-treading vesicle [Kantsler and Steinberg, Phys. Rev. Lett., 95, 258101 (2005)]. It is also shown that the velocity of the inner fluid close to the membrane is not constant along the circumference, and it implies the possibility of a three dimensional flow field of the lipid molecules or an apparent stretching motion of the membrane having hidden surface area due to the thermal fluctuation.

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We had developed the vibrating flow pump (VFP) for left ventricular assist device based on the fluid dynamical analysis and the animal tests. The main advantages of VFP were generating the oscillated blood flow and having simple mechanical structure. In this study, we constructed an experimental apparatus for a prototype artificial heart and lung by means of installing hollow fibers into the vibrating tube in the VFP. The characteristics of gas exchange were investigated both by experiment using bovine blood and by numerical analysis. The unsteady, incompressible, and axisymmetric Navier-Stokes equations and diffusion equation were solved based on finite difference technique. In the prototype VFP, the effect of the oscillated flow on the gas exchange was relatively small in the range of Reynolds number of O (1) -O (1 000). Comparing experimental and numerical results, we discussed the validity of the numerical analysis and predicted the characteristics of the VFP. The basic design data of VFP installing hollow fibers were accumulated for the artificial heart and lung.

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In order to achieve an in vivo simulation of the circulatory system, it is important to apply appropriate physiologital conditions such as physical properties, models, and boundary conditions. In this paper, we focus on modeling of outflow boundary conditions taking account of the effects of peripheral vessel network for hemodynamic simulation. The network of cerebral arteries is modeled including the arteries and arterioles, whose sizes can not be resolved by MRA. The peripheral resistance, compliance, and impedance are treated by one-dimensional simulation and zero-dimensional model of the network. The present method is applied to two patient-specific models with or without occlusion in the cerebral arterial circle of Willis. As a result, particularly in the case with occlusion, the present method shows a significant difference in the flow rate of each artery and also improvement in blood flow distribution in the network comparing to the simulation with free-stream boundary condition.

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Recently, it has bemome a social problem that the disease infection by the pathogenic micro-organism spreads all over the world. Therefore, it is expected to establish an advanced sterilization method which has the advantages of simple configuration and ability to operate at atmospheric pressure. We studied the sterilization effects of the steam plasma flow at atmospheric pressure on bacteria. We developed a plasma source of the steam plasma flow at atmospheric pressure in a quartz tube of 8 mm in diameter and clarified its plasma characteristics and sterilization efficacy against Geobacillus stearothermophilus. A flow rate of the steam plasma flow of atmospheric pressure in a tube is 8.1 L/min which equals to the velocity of 2.7 m/s. When the applied voltage was 13 kV_pp and its frequency was 3 kHz, the discharge current of 62 mA and the discharge power of 30 W were observed. Under this condition, a good sterilization result of G. stearothermophilus was obtained for the sterilization time of 30 minutes.

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Natural convective flows around an array of vertical heated plates were investigated experimentally. Main concerns were directed to the influences of plate numbers on the heat transfer characteristics of the plates. The both surfaces of the test plates were heated with constant and equal heat fluxes and their local heat transfer coefficients were measured. The results showed that the coefficients of the surfaces facing outward become higher than those facing inward of the array. The flow fields around the bottom of the plate array were visualized with smoke. The result showed that the ambient flow directs from the sides to the center of the array and enters the parallel channel obliquely. These flows cause the above difference in the coefficients. While the above difference gradually diminished in between the plates placed in the central part of the array, and their coefficients asymptote to those of the empirical equation that assumed a uniform velocity at the channel inlet.

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Experimental investigations have been carried out for opposing mixed convective flows of air adjacent to downward-facing, inclined heated plate. The experiments covered the ranges of the Reynolds and modified Rayleigh numbers as, Re_L =400-4 600 and Ra_L*=1.0×10⁷-5.4×10⁸, and the inclination angles as; θ= 15 to 75°from horizontal. The flow fields over plates were visualized with smoke. The results showed that a separation of forced boundary layer flow occurs first at the bottom edge of the plate, and then, the separation point shifts toward upstream with increasing the wall heat flux, and finally, reaches to the top edge of the plates. It was found that the separations at the bottom and top edges are predicted with the non-dimensional parameter as; (Gγ*_Lθ/Re_L^2.5) = 0.35 and 1.0, respectively. The local heat transfer coefficients of the inclined plates were also measured and the results showed that minimum coefficients appear in the separation region. Moreover, it was revealed that the forced, natural and combined convective flows can be classified by the non-dimensional parameter (Gγ*_Lθ/Re_L^2.5).

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Two rectangular block-like elements as an electronic module are positioned in a parallel-walled channel and cooled by forced convection airflow. A metal plate without holes as a barrier protrudes above the plane of the modules, which is intended to function as a cover for protecting them from mechanical or electromagnetic damage, or as a thermal control device. Per-module heat transfer coefficients in the presence of the barrier of various gap, G, between the barrier and the channel and distance, L, between the module and the barrier were measured. In the presence of the barrier, the heat transfer coefficient at the 2nd row module is enhanced, but is diminished at the 1st row module. Nusselt numbers are correlated as a function of Reynolds number and G/L.

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A new technique of catalytic CVD growth of single-walled carbon nanotubes (SWNTs) is developed using a mixture of carbon monoxide and hydrogen as carbon source and reaction enhancing agent at atmospheric pressure (COCCVD technique). High-quality SWNTs are produced on a quartz substrate dip-coated with Co and Mo bimetallic catalysts nanoparticles. A dramatically enhanced yield of SWNTs by mixing an equimolar amount of hydrogen to carbon monoxide was explained by a proposed mechanism based on the reaction thermodynamics. Contribution of the 'reverse water-gas reaction' and the'reverse water-gas shift reaction' in addition to the Boudouard reaction is the key chemical reaction steps. Since this mixed gas is abundantly available in coal gasification plants and natural gas reforming plants, production of SWNTs in such plants can be proposed.

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The catalytic reaction mechanism in the growth process of single-walled carbon nanotubes (SWNTs) is considered for carbon monoxide catalytic CVD (COCCVD) and alcohol catalytic CVD (ACCVD) methods. Combinatory CVD experiments were carried out employing a wide variety of catalyst metals, ranging from commonly used transition metals such as Co and Mo to noble metals such as Au and Pt. As a result, we propose that difference in eletronegativity is a key factor to choose a pair of binary catalysts. In the efficient catalyst reaction for a combination of catalyst metals with large electronegativity difference, the metal atom with larger electronegativity functions as a carbon bonding site, and other metal atoms help the dissociation of H₂. For the combination of similar electronegativities, the metals have no work-share. Furthermore, catalytic activity of Au and Pt are demonstrated for COCCVD in addition to the previously reported ACCVD with adequate heat-treatment condition.

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In order to control the morphology of single-walled carbon nanotubes (SWNTs) grown on a flat substrate by using CO catalytic chemical vapor deposition (COCCVD) method, several catalysts preparation methods and different amount of hydrogen addition are examined. As a result, we found optimum conditions for the sparse horizontal growth and novel vertically aligned growth. From this experimental survey, we discuss that the distance between catalyst nano-particles on a substrate has a crucial role for the determination of the final morphology of SWNTs. Vertically aligned growth is obtained by decreasing the distance between catalyst nano-particles during catalysts preparation, and by preventing from the deactivation of catalysts particle due to wrapping of carboneous material at the initial stages of CVD.

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In this research, optimum spray atomization is verified in the liquid injection with the microwave heating technology, the local contact microwave heating. The fuel used was ethanol, which is valuable in biomass-origin fuel. The fuel was jetted seven times, once every five seconds. The experiment time was 30 seconds. The spray was photographed using a 130 Mpix color CMOS digital camera. The feature of the spray that could be appreciated by the pictures was defined as the droplet dispersion area. The photographs were qualitatively evaluated with simple image data processing. As a result, the droplet dispersion area was increased with microwave heating. This shows that there is a possibility of change through spray atomization.

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3-D movement of flame fronts in propane-air turbulent premixed Bunsen flames have been examined by a four-element electrostatic probe. Measurements were conducted at three different positions in a turbulent flame brush, one position on the centerline and two positions off axis. The probability distributions of the magnitude and of the direction cosines n_j of the velocity vector of the flame-front propagation are examined. This paper reports results obtained at the off-axis positions in a propane-air turbulent premixed flame of the equivalence ratio of 1.10. Flame-front movements were observed to depend on whether the flame front moved the probe in the direction of the unburnt-to-burnt or burnt-to-unburnt. When the flame front moves in the unburnt-to-burnt direction, it moves symmetrically in the tangential direction and toward the burner axis in the radial direction. When it moves in the burnt-to-unburnt direction, it moves symmetrically in the tangential direction and away from the burner axis in the radial direction. Effect of the thermal expansion on the magnitude of the velocity vector of the flame front is seen to be quite appreciable toward the downstream region.

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3-D movement of flame fronts in propane-air turbulent premixed Bunsen flames have been examined by a four-element electrostatic probe. The probability distributions of the magnitude and of the direction consines of the velocity vector of the flame front have been examined at three different positions in a turbulent flame brush, one position at position A and two positions off axis. This paper reports results obtained from flames of 0.80 and 1.40 equivalence ratios. At position A, velocity vectors of the flame front are distributed symmetrically around the burner axis independent of whether the flame front passes from the unburnt-to-burnt or burnt-to-unburnt direction. Off axis, velocity vectors of the flame front are mainly distributed towards the burner axis for the unburnt-to-burnt passage, while they are mainly distributed toward the outer side of the burner for the burnt-to-unburnt passage. Distribution of the magnitude of the velocity vector of the flame front for the former is slightly asymmetrical, with a tail to high velocity and that for the latter is asymmetrical, with a tail extending to low velocity and a sharper cut-off at high velocity. Effects of the direction of the flamelet propagation with respect to the gas and of fluctuation of the gas expansion tend to add to the flame-front for the former, but subtract from it for the latter.

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In this paper, experimental results were reported to investigate a behavior of combustion wave when a shock wave was transmitted into a combustible premixed gas of oxygen and hydrogen. In general, phenomena occurring in the premixed gas would be classified into four types, i.e. (a) the shock wave was just transmitted without causing ignition for the shock wave propagated with low-Mach number, (b) the gas was ignited behind the shock wave and a deflagration wave was propagated following the shock wave, (c) the deflagration wave was transited to a detonation wave behind the shock wave, (d) a detonation wave was directly initiated just behind incident shock wave having high-propagation Mach number. In this study, a shock wave produced by a detonation-driven shock tube was transmitted into a premixed gas of oxygen and hydrogen varied with an equivalence ratio, initial pressure of premixed gas and Mach number of the shock wave. As a result, the phenomena of combustion wave were classified using a cell-size of steady-propagating detonation wave. For sensitive gases having small cell-size, the detonation wave was directly initiated behind the shock wave even though the Mach number of the shock wave was relatively low. Empirical equations to evaluate a Mach number and temperature behind shock wave were obtained, which are threshold parameters to cause detonation wave behind transmitted shock wave.

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A low NO_x combustor for kerosene-fueled micro gas turbine based on a new concept was proposed. The combustor consisted of primary and secondary combustion zones, and they were connected by a throat. A swirler was set between the primary and secondary combustion zones. In order to enhance recirculation of burned gas in the primary combustion zone, combustion air was introduced through the swirler and forced to flow upward to the combustor bottom. In this study, fundamental combustion characteristics such as lean combustion limit, exhaust gas composition and combustion gas temperature were measured using three fuel atomizers which rated flow rates were 3.0 gallon/h, 4.5 gallon/h and 6.0 gallon/h respectively. It was shown that the combustion stability and emission characteristics in the case of 3.0 gallon/h nozzle were superior to those in other cases. Further, gas velocity in the primary combustion zone was measured by Leaser Doppler Anemometer (LDA) and behavior of the recirculation of burned gas was investigated.

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A low NO_x combustor for kerosene-fueled micro gas turbine based on a new concept was proposed. The combustor consisted of primary and secondary combustion zones, and they were connected by a throat. A swirler was set between the primary and secondary combustion zones. In order to enhance recirculation of burned gas in the primary combustion zone, combustion air was introduced through the swirler and forced to flow upward to the combustor bottom. In this study, effects of configuration of primary combustion zone on combustion gas flow in it were investigated. The length of primary combustion zone, swirler vane angle, diameter of throat and height of guide vane were changed independently from the standard configuration. Distributions of gas flow in the primary combustion zone were measured with LDA. The relation between combustion stability and the distributions of gas flow was discussed, and it was found that appropriate combustion gas recirculation in the primary combustion zone was necessary to keep combustion stability high.

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In order to reveal the soot removal mechanism in Electric Diesel Particulate Trap (E-DPT), mechanism of soot trapping and re-burning of soot particles in exhaust gas was investigated using one channel electric diesel particulate trap (1 channel E-DPT). The E-DPT is capable to trap soot particles by applying DC electric field between electro-plates. The results showed that soot particles like a whisker grew up from negative electrode side toward positive one. Soot particles trapped on the plates formed many soot bridges in narrow space between electro-plates. Formation of soot particles depended on electric intensity. In the condition of F=200kV/m, lumps of soot were observed instead of whisker like soot bridges and soot trapping and soot re-burning were balanced. Ignition of the soot lump was occurred at the contact point between the lump and electro-plate, however re-burning of whole the lump was rarely observed. Remained soot drifted to down stream. It is thought that many remained soot particles were discharged from the E-DPT. Incomplete re-burning of soot lump caused soot removal efficiency deterioration of E-DPT. In the case of narrow space and high electric intensity (F=600kV/m, L=0.5mm), however, soot bridge re-burning was main phenomenon and soot lump re-burning was controlled.

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For development and analysis of new diesel combustion system which fulfills the features of common-rail injection system such as multiple injections, an advanced single-cylinder optically accessible engine with very wide observation field was developed. The combustion chamber of this engine can be optically accessible from three directions of top, bottom, and side. In addition to direct observation of phenomena in the piston cavity and the squish area, 2-dimentional laser diagnostics in arbitrary cross sections are possible. In this paper, we introduce the details of this engine and examples of in-cylinder visualization with this engine ; 1) direct observation of the soot reduction mechanism of after injection, 2) visualization of mixture formation of pilot injection using LIF, 3) validation of an in-cylinder EGR stratification technique by LIF measurement.

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Water to gas oil (W/O) emulsified diesel fuel has been researched actively to reduce the load on the environment. However, this is due to the large drop-size distribution and the polydispersion W/O emulsion produced by an agitation-type method. We examined the characteristics of the microscopic-monodispersion emulsified fuel by using a Shirasu Porous Glass (SPG) membrane, which was made from volcanic ash called “Shirasu”. The microscopic emulsion from the 1-micrometer pore diameter of the SPG membrane was examined with respect to the combustion characteristics on a direct diesel engine. The major results are as follows; (1) The particle size of gas oil emulsion increases to about 3.5 times the pore size of the original SPG membrane. (2) The particle distribution showed monodispersion and, thus, can make an ideal monodispersion microscopic W/O emulsified fuel for diesel engines. (3) By using the microscopic monodispersion emulsified fuel we can remarkably reduce the both emissions of NO_x, CO, HC, Soot and PM, and fuel consumption by 5-15% compared the base gas oil.

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