This study was focused on relation between flow field and performance of a torque converter for various speed ratios. The converter was consisted of three components; pump, turbine and stator. The speed ratio was defined as the turbine to the pump speed. The detail flow fields around these components were visualized and evaluated based on numerical simulation results. The flow separation is one of the major interests in the converter and it was estimated from stream lines, distribution of pressure, velocity and vorticity in previous study. The authors tried in this study to identify the local flow separation around these blades based on Q criterion which was supposed by Hunt et al. for better prediction of the performance. As a result, it was able to grasp the detail vortex formations and reveal the relationship between these flow fields and the performance of converter at various speed ratios.

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In order to clarify the mechanism of the instability phenomenon which occurs when a pump-turbine stops suddenly, the experiment and the numerical simulation for the pump-turbine were performed in this research. The pressure are measured at inlet and outlet changing flow rate. Serpentine curve was observed on characteristic curve obtained from experimental and numerical result. The past research clarifies that appearing serpentine curve means instability phenomenon occurs. The numerical result shows that as the flow rate decreases, the torque coefficient decreases. The loss coefficient decreases when flow rate is more than design flow rate and it increases when flow rate is less than design flow rate. Serpentine curve appears when the torque coefficient's decrements exceeds rather than the loss coefficient's increments. Various losses which occur at pump-turbine's each parts calculated from numerical result are modeled mathematically.

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The mini centrifugal pump is widely used in the fields of industry and medical science, such as the cooling system of the fuel cell and the high-performance PC, and the ventricular assist device. Further downsizing and energy saving is required, and the investigations related to the internal flow is necessary in order to enable the high pump performance. In this research, the splitter blades are installed to the impeller of the mini centrifugal pump. And the splitter blades length is changed to research the influence of it on the performance and internal flow. The performance test was conducted by the experiment and numerical analysis. Furthermore, the internal flow was investigated by numerical analysis.

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Fluid-food pump used for the process of food supply is required for keeping high performance, decreasing shear loss and simple maintenance and so on. Although, the influence of the fluid food on pump performance and the ideal design method of the fluid-food pump are not clarified, also the design method based on the internal flow conditions is hardly conducted. In this research, a centrifugal pump having small number of blade and open and semi-open impeller was used to decrease shear loss and keep wide flow passage. In this paper, the pump performance and internal flow conditions including the main shroud clearance of the centrifugal pump using low viscous fluid were clarified by experimental and numerical analysis results.

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The contra-rotating axial flow pump with two rotors rotating reversely, has been proved with remarkable performance benefits as well as the significant interaction between blade rows in our previous experiments. In the present study, the rotor speed combination of front and rear rotors, which gives the better hydraulic efficiency, is discussed using one dimensional stream tube theory considering momentum conservation laws. Since it was theoretically indicated that reducing the rear rotor speed is effective for the improvement of efficiency, three types of rear rotors are designed, whose performances are evaluated by CFD. It is found that the reduced speed design of the rear rotor is actually effective, but the further considerations are needed for more appropriate design.

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In pumps and water turbines, the rotordynamic force and moment can cause shaft vibrations. The fluid force which acts on the backshroud of the impeller and runner generates the fluid moment, and it can cause the whirling motion of the rotor. We made a test facility in which the backshroud was modeled by a rotating disc and could observe the whirling motion of the rotor. By the simulation of the flow around the whirling disc, we found that the fluid moment acted on the disc. Therefore, it was releaved that the rotordynamic fluid moment excites the whirling motion.

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Rocket turbopump has suffered from rotor vibration problems. Mechanical seal is often applied to separate turbine from pump in the turbopumps. In this study, we measured rotordynamic characteristic of mechanical seal under whirling motion. Rotordynamic force of this seal was measured by the rotordynamic test stand (JARTS) with active magnetic bearings. It was found that the mechanical seal has extremely small rotordynamic force and do not affect rotor vibration.

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With respect to a viscous micropump using a rotating cylinder in a curved duct, the influences of the angle of the curved duct on the pressure performance and flow field were investigated. The model experiment, the numerical simulation and the theoretical analysis were performed. The theoretical analysis has the qualitative agreement with the numerical simulation. With an increase of the angle of a curved duct, the pressure coefficient at the zero flow coefficient is increased and the flow coefficient at the zero pressure coefficient is slightly decreased. Near the zero pressure coefficient, the vortices at the upstream and downstream of the rotating cylinder are observed.

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We have constructed and applied a new cavitation model called "Multi-process Cavitation Model", which takes the various elementary processes in cavitation into account, for cavitation in cold water and that in liquid nitrogen as one of the cryogenic fluids. The proposed model was validated through CFD simulation around a hydrofoil, and compared the present results with the other simulation results and the experiments. As a result, the present model could predict the lift coefficient and surface pressure distribution better than the other cavitation models in the case of cold water while it could not accurately predict the temperature distribution in the case of liquid nitrogen, which is our near future work to be improved.

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Active Charge Accumulator (ACA) was developed as high efficiency pressure converter in Aqua Drive System. But the detail characteristic of ACA has not been revealed yet. This study especially focused on the depressurization efficiency under several flow rates and valves switching conditions of ACA. If water pressure is decreased, then flow rate is increased in the depressurized process in case of ACA, it is main reason of higher efficiency compared to that with control valves. As a result, the energy conversion efficiency is independent of the supplying flow rate. The working frequency of ACA increases with the flow rate. There is upper limit of the frequency owing to capacity of ACA. Stability of supplying pressure by ACA is independent of the flow rate, but threshold value of valve switching of ACA has great influence on the supplying pressure.

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In this numerical study, the time-averaged and instantaneous heat transfer are assessed in terms of the self-oscillating fluidic device. This fluidic oscillator consists of one inlet, two outlets and two feedback loop channels. The fluid flows a feedback loop channel alternately and results in the impinging jet fluctuation. This self-fluctuating phenomena have successfully been simulated by numerical simulation. As a result, the linear relation between the input flow rate and oscillating frequency is indicated. Utilizing the self-oscillating fluidic device for wall cooling, lots of local maxima of the time-averaged and instantaneous Nusselt number were obtained at the hot target wall. This is because the quasi-steady impinging jet generated by the self-oscillating fluidic device produces the quasi-steady vortex.

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The moisture separator reheater (MSR) is a facility which is used to improve the thermal efficiency for the nuclear power plant. We have been developing the technique to improve moisture separation efficiency of MSR using wire-mesh combined with wave-shaped vanes. The objective of this study is to clarify the wire-mesh configurations which can minimize the exit moisture by droplet diameter measurement. We confirmed that droplet diameters were increased and the exit moisture was reduced as the number of layer was increased. Within our experiment range, six layered wire-mesh with 0.65 mm diameter can minimize the moisture, which is reduced from 0.45% without wire-mesh to 0.08%.

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Aimed at improving the quality and the efficiency of the coating, we have investigated the motion of liquid particles in an actual airless spray by using a high speed video camera. In this study two-dimensional velocity vectors of the particle were quantitatively obtained by the mean shift algorithm and the particle tracking method. We show the statistical analysis for the particle size, the direction, and the velocity of the liquid particles in the actual spray, and discuss their roles on the quality and the efficiency of the paint coating.

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The pressure is calculated by using CFD velocity distribution of car wake flow obtained by the PIV measurements. It is studied how to reduce PIV measurement errors. Then it is found the location of boundary edges should be carefully selected as well as the method of imposing boundary condition should be carefully given. It is also found averaging velocity reduces estimation error.

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A comfortability of passenger in vehicle depends on a lot of parameters, as an ambient temperature, driving speed, radiant temperature, air humidity, rate of metabolism of passenger, and thermal insulation of clothing. In order to consider the circumambient influence, it is important to evaluate the comfort of the occupant as to visualize the thermal environment in vehicle, in addition for this aim, -we need to optimize air-conditioning equipment HTVA.C. The purpose of this study is to simulate the heat transfer and air flow interior of vehicle. The physical parameters which are important in evaluating the comfortability has been investigated to discuss the time response of thermo-fluid dynamical influence. Since the thermal environment in the vehicle is so greatly affected by solar radiation, it is necessary to build up the numerical model which was especially associated the solar radiation. In this report, we have considered a vehicle interior model by taking into account with the solar radiation and visualized the temperature distribution and velocity distribution.

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We confirmed the superiority of the flow of the new 3D-blades by Computational Fluid Dynamics(CFD) for the high efficiency of the turbofan for package air-conditioner indoor units. As a result, the new 3D-blade fan reduces the flow-separation at the leading-edge and blows out uniformly form the outlet of the fan. In addition decreasing of 15% of axis power by the CFD result, and reducing of fan motor input 11% by the actual machine evaluation.

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In order to clarify the influence of diffuser on the characteristics of a forward curved fan, the influence of bare ratio and outlet angle on the characteristics of the fen was analyzed by the experiment of the actual fen and the numerical simulation. In this study, the mechanism of the discrete frequency noise generated due to the separated flow of the diffuser is discussed. The optimized bare ratio was in the vicinity of 17°. The fan separated inside of the diffuser generated the discrete frequency noise due to interaction between the reversed flow from the diffuser and the impeller rotating at the blade passing frequency. The efficient outlet angle existed within 10° to 15°. The diffuser made by the outlet angle contributed for increasing the pressure ratio than that of the bare ratio. Furthermore, we clarified that to restrain the separation in the diffuser is effective for decreasing the fen noise.

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Centrifugal Turbo-Blower is able to produce high pressure, but operation sound of it is bigger than that of other blowers. The mechanism of the noise generation has to be elucidated in order to decrease that noise. In this study, we focus on lap area (gap between inlet pipe and impeller) which affects blower noise, and investigate the noise at lap area by measurement of noise and velocity fluctuation and numerical analysis. As a result, we found that noise have relation to a re-entrant flow, and the interaction between the re-entrant flow and inlet flow increases velocity fluctuation which causes the noise at lap.

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The noise generated from the internal flow in a centrifugal fan was computed by computational aero-acoustics (CAA). The sound sources were obtained by large-eddy simulation (LES) of turbulent flow in the centrifugal fan. The computed sound pressure level (SPL) agrees fairly well with the experimental data in the frequency range from 400 Hz to 2000 Hz. Fluid forces acting on the impeller at the plane perpendicular to the axial direction play important role on the predicted SPL. The peak of SPL at blade passing frequency (BPF) of 600 Hz is not captured by CAA.

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In the present paper the attention is focused on the relation between the vortex shedding and acoustic pressure fluctuation on acoustic resonance which occurred in the two-dimensional model of boiler. We measured the characteristics of acoustic resonance, the pressure fluctuation on the surface of tubes at the nodes of acoustic pressure and the acoustic pressure fluctuation on the side wall. If the acoustic resonance occurred, the peak level of spectrum of surface pressure and the coherence between vortex shedding and wall acoustic pressure in the tube banks also increased. The time variation of amplitude of surface pressure fluctuation repeated the increase and decrease although the acoustic resonance occurred. The time variation of amplitude of wall pressure fluctuation also repeated the increase and decrease. However, the minimum magnitude of wall acoustic pressure did not became 0, because there were many tubes in the tube banks.

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In order to clarify the effects of the distance between the plates on aerodynamic sound and flows around a cascade of flat plates, wind tunnel experiments were performed with the various ratios of the distance between the plates to thickness, s/b = 0.5, 1.0, 1.5, 3.0, 6.0 and 13.0. For s/b = 6.0 and 3.0, the intense aerodynamic sound with acoustic resonance radiates. For the large distance of s/b = 13.0, as the freestream velocity increases, the variation of the sound pressure level does not have local maximum. This indicates that acoustic resonance becomes weaker. For the smaller distance of s/b = 1.0, the frequency of the vortex shedding from each plate differs between neighboring plates. As a result, the resonant acoustic radiation becomes weaker. For the much smaller distance of s/b = 0.5, the intense vortex formation does not occur in the wake of each plate and intense tonal sound does not radiate.

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This study deals with the aerodynamic noise generated from a valve in an exhaust system. Because of the aerodynamic noise, noise reduction effect of actual exhaust system is less than a theoretical valve. The aerodynamic noise from the valve, generated for the condition of valve and flow velocity distribution in order to find the relations of flow velocity distribution and aerodynamic noise generated from the valve, valve set angle and valve mounting position changed. The result shows that the flow velocity distribution and valve mounting position have the effect of noise reduction.

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Noise and vibration control are the one of important issues for engineering. A sound insulation cover which envelops a sound source is very useful for the noise reduction. When large noise and high temperature heat are emitted from the sound source, we have to consider the heat cooling as well as the noise reduction. The purpose of the present study is to investigate the acoustic characteristic of a sound insulation cover with and without a small hole using acoustic/structure coupled analysis. The effect of hole size and position were also investigated. Although a lot of sound leaked from a large size hole, a small size hole hardly influenced the sound insulation performance of the cover. It is clearly that sound pressure distributions around the cover changed obviously according to the input frequency of a sound source.

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Longitudinal vortex system was produced by a three-dimensional delta wing. The wing with attack angle of 15 degrees was merged in the uniform flow speed of 0.4m/s. Generation mechanism of longitudinal vortex and the structure of the vortex system were clarified by CFD. Tip angles range from 40 degrees to 140 degrees. As a result, it was found that vorticity has a great influence on pressure coefficient on the wing. Vorticities and pressure coefficients have their maximum values around 80 degrees and 100 degrees, respectively. Structure of the vortex system was captured clearly.

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A muffler is attached to the exhaust duct of a diesel engine, and aerodynamic noise is generated by exhaust gas flows into the muffler. The jet flow diffusion device diffuses an air flow inside muffler. An air flow flowing into the jet flow diffusion device flow out outside through the perforated metal and slits. In this study, we performed measurements of the aerodynamic noise changing by perforated metal, the cone position and an attachment position of the support. Then, in order to clarify the aerodynamic noise sources, we performed measurements of the velocity fluctuation of the flow of air flowing out of the jet flow diffusion device. The result of the aerodynamic noise measurement experiment shows that the SPL increases when cone position is on the upstream side.

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In this paper, three components of flow velocity around NACA0012 airfoil in some two dimensional sections are measured by using the stereo P1V method in order to clarify flow structures and unsteady behavior of airfoil tip flows contributed to tip flow noise. The Reynolds number based on the chord length of the airfoil and uniform flow velocity is 1.3×10^5 and 3.3×10^4, and the airfoil is under the high lift condition. Band pass filtered characteristics with velocity distributions are shown.

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The splash caused by a falling water droplet is often seen in our life but the noise induced by it sometimes annoys us. In the present paper, the form of splash was observed using high speed camera in order to reduce the noise and compared between the form of splash when a droplet fell into the water tank with flat bottom and that when a droplet fell into the water tank with slope bottom. As the result the column-type splash formed by the droplet on the slope bottom inclined to the upper direction of slope and the noise by splash was disappeared.

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Recently, it's a problem of aerodynamic noise radiated from wind turbine. One of numerical aeroacoustical code for wind turbine noise prediction is FAST, constructed based on the airfoil noise prediction model. However, prediction accuracy in codes isn't enough. In this study, it's aimed for database construction of airfoil noise on the inflow turbulence and for improvement of the prediction model based on the results by wind tunnel test using active turbulence generator (ATG). In this paper, it's shown that airfoil noise can be measured under the turbulence intensity of 10 to 20 % and eddy scale of 300 to 1600 mm. The three types of airfoil models have wing sections of NACA0012, DU96 and S831, their chord length of 150 mm and aspect ratio of 3.3 as two-dimensional model, respectively. It's clear that turbulent flow affects as same frequency range on velocity spectra as on sound spectra, but airfoil shapes do not affect it.

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In order to make a strong turbulence field in a wind tunnel, the properties of 3-D multi-scale turbulence grid using fractal was experimentally investigated. The intensity and scale of turbulence generated by the developed multi-scale turbulence grid were larger than that of the conventional grid turbulence. On the other hand, the turbulence Reynolds number of the developed grid was smaller than that of an active turbulence generator. Since the structures of suggested turbulence generator is simple compared to the active turbulence generator, it seems to be suitable application to generate large scale turbulence for an actual scale automotive wind tunnel.

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The typhoon makes a serious damage to the apple farmer by dropping apple before the harvest due to the strong wind. We investigated the drag coefficient C_D of apple models. We are focusing on the influence of the bag to cultivate the delicious fruit. The C_D was obtained in experimentally with or without bag. The drag force and the shear stress of stem under the condition of typhoon were determined from the obtained C_D. The drag force increased with using a bag, so that the shear force acting on model also increased. The obtained shear stress was compared with allowable shear stress of real tree. The direction of bag realizes the shear stress less than the allowable value. Thus, the dropping apple due to strong wind can decrease with the suitable shape of bag to decrease the drag force.

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Drug inhaling therapy for the asthmatics was investigated in the present report. The treatment is a noticeable therapy for the patients required to take medicine not only asthma, but also other disease. In order to achieve an effective drug delivery and to reduce the side effects such as inflammation, we aim accurate prediction according to the particle depositon rate to estimate appropriate particle diameter and inhale flow rate for individual patient. In this report, we performed particle tracking simulation in a 3D model reconstructed from DICOM images. Then we calculate the efficiency of the particle transport in oropharynx through oral cavity. Consequently, we demonstrated the particle deposition rate has been related to the Stokes number and curvature of a streamline in flow.

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We developed a micro multipoint laser Doppler velocimeter (μ-MLDV) for noninvasive in-vivo measurements of blood flow and we presented the results of demonstrations performed on experimental animals. In this paper, we investigate the validity of power spectrum analysis for determining the flow velocity and the minimum power of the semiconductor laser in the μ-MLDV. Average velocity of blood flow was estimated from a peak position in the power spectrum. The laser power was reduced from 140 to 30 mW since 30 mW was the minimum power at which images of blood flow velocity in microvessels could be obtained. About 30 mW (power density of 15 mW/mm^2) is the maximum power which can be irradiated to humans. Further reduction in the laser power is necessary before this technique can be applied to humans.

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Predicting the flow distribution of the liver is important to consider the optimum conditions when developing new medical treatment for liver diseases. However, these predictions are difficult because of the multiple functions and the complex structure of the liver. In this study, a hybrid liver perfusion model using a computational fluid dynamics (CFD) analysis with a porous medium was developed. This hybrid liver perfusion model consisted of three parts: a portal vein part represented an inlet vessel, a hepatic vein part which represented the outlet vessel and the liver tissue part, which was represented by a porous medium. As a result, the flow rate distribution calculated using this analysis was in good agreement with experimental results of the weight distribution of the hepatic lobes. Therefore, This model could be a powerful tool for enhancing to develop the novel medical treatments.

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A glycocalyx layer on endothelial cells is considered to play an important role in sensing of fluid force of blood flow. In order to investigate particularly an influence of glycocalyx layer on the blood flow, a high spatial resolution and high accuracy velocity measurement technique was developed. In the technique, we use confocal micro PIV and super-resolution microscopy to measure the flow field near the layer. Additionally we developed a special tracer particle fabricated by a silica particle and polyethylene glycol to improve the accuracy of PIV. As the result, a measurement technique for three dimensional velocity distributions with lateral resolution of 6.8 μm and depth resolution of 250 nm was realized to investigate particularly an influence of glycocalyx layer on the flow.

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Magnetic compound fluids additionally containing needle-like particles are produced as new working fluids of dampers. Two kinds of needle-like particles are prepared for the experiments: one is iron particles (ferromagnetic particles), the other is hematite particles (paramagnetic particles). Damping force of the damper utilizing such magnetic compound fluids is investigated by using a simple prototype damper. The damping force of the damper increases with increasing the mixing amount of needle-like particles even though the same amount of micrometer-size magnetic spherical particles is decreased. The magnetic compound fluid containing small amount of magnetic fluid produces strong damping force in the presence of magnetic field.

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In the present study, we conducted experiments for thermo-magnetic natural convection of TSMF by applying uniform magnetic field in a cubic cavity. This study focused on the heat transfer and flow characteristics of thermo-magnetic natural convection with non-magnetic particles. From experimental results, it was found that heat transfer was enhanced with imposing an external magnetic field when the non-magnetic particles are immersed in the thermo-magnetic natural convection. It was realized that the heat transfer characteristics of the thermo-magnetic natural convection with non-magnetic particles depend on the intensity of magnetic field, size and number of the particles immersed in the convection.

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When a magnetic field is applied to a magnetic fluid, ferromagnetic particles form clusters. Clusters increase the viscosity of a magnetic fluid so the magnetic fluid flow characteristic can be controlled by magnetic field. Today, magnetic fluid is applied to damper, speaker, aseismic device, etc. There are many experimental studies about magnetic fluid cluster formation under DC magnetic field. However, there is not sufficient information about the experimental investigation under AC magnetic field. Then, we performed the present study. We investigated the cluster formation and the effect of clusters on two-dimension flow in a square duct under DC and AC magnetic fields.

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Advanced water treatment technologies using OH radical and O radical have been studied. The persistent organic substances such as dioxins which cannot be decomposed by even ozone. OH radical and O radical can decompose these substances since they have stronger oxidation potential than that of ozone. In this study, acetic acid was used as a model of persistent organic pollutant. Acetic acid decomposition experiments were carried out by using multiple bubble jets with nanosecond pulsed discharge. In order to obtain optimum conditions, the effects of various applied voltages and anode geometry on the decomposition rate and energy efficiency were clarified.

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The highly temporal streak imaging of an underwater discharge revealed that the primary streamer propagation was intermittent though the propagation had been considered continuous from our previous study. In addition, the intermittent luminescence pattern was synchronized with the pattern of discharge pulsed currents. The primary streamer in ultrapure water was generated by the application of a single-shot pulsed positive high voltage with a duration of 10 μs to a needle-wire electrode system with the tip radius of 40 μm and with the gap distance of 6 mm.

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The stripping technology of single-wafer processing using ozone is proposed on photoresist stripping in the semiconductor manufacturing in order to reduce the environmental burden. In the present study, we utilize the ozone microbubble with a venturi tube. First, the generation of the ozone microbubbles in the venturi tube is observed via a high speed video camera. Next, to clarify the effect of the superficial liquid velocity, the superficial gas velocity and ozone water concentration on the photoresist stripping rate, the photoresist stripping experiments is conducted. As a result, it is observed that the ozone water concentration affect the photoresist stripping rate. However, compared with the existing research, in this stripping system, it is suggested that both the superficial liquid velocity and the superficial gas velocity affect the photoresist stripping rate more effectively.

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Magnetorheological (MR) fluids are suspensions of micron-sized magnetic particles dispersed into carrier oils, and behave like a Bingham fluid with magntic-field responsive yield stress. In this research, bidisperse MR suspensions consisting of micro (6.6 μm) and nano (110 nm) iron particles dispersed into silicone oil were fabricated to investigate the relationships between the magnetic field-induced particle cluster structures and the MR responses. The particle cluster structures formed in the suspensions under applied magnetic fields were visualized using an optical microscope in a transmission mode. As well known, the particle chains formed roughly along to the applied magnetic field were observed for the suspension containing the micron-sized iron particles. The MR responses of the bidisperse suspensions changed significantly as a function of the solid fraction of nano-particles. Interestingly, field-induced shear stress was enhanced when the solid fraction of nano-particles was 25%. The enhancement of the shear stress can be attributed to the formation of distinct and wide particle cluster chain

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In this study, the relationship between the share stress by a magnetic functional fluid and the polished material's removal quantity was investigated on the precision processing of vertical tube inner wall utilizing a magnetic compound fluid. On the processing experiment, two kinds of tools consisted of one ring-shaped permanent magnet were used. And the shear stress to act on the each tool and the removal quantity were measured. From the experimental results, the correlation between them was clarified. It can be suggested that the processing pressure induced by the shear stress was related to the removal quantity.

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Innovative energy conversion device has been developed for efficient wind energy utilization. This device has co-axial configuration and the rotational speed of the turbine can be kept constant by controlling rotational torque by Lorentz force with electrical power generation. The overshoot occurs in motor torque for the step-like change of rotational speeds due to the inertial of the liquid metal flow. With increasing the rotational speed from 1000 rpm to 1500 rpm, the change in the motor torque a little with increasing the magnetic flux density, because of the moderate response of the liquid metal flow by electromagnetic interaction.

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Recently, electrohydrodynamic (EHD) flow driven by applied external electric force is attracting a lot of interests. As usual, EHD flows require at least several tens volts of applied voltage. In this study, we aim to find out a method to induce EHD flows with the lower applied voltage. A reservoir filled with NaOH solution is divided by an anion-exchange membrane that has a small pore. Applying electric potential, a cation flow can be observed in the pore when the cross-sectional area of the anion-exchange membrane is 200 times larger than that of the pore. By applying a 2.2 V of voltage, electric signals and velocity fields in the pore are simultaneously measured.

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In this study, focusing on self-assembled pattern formation of molecules on various substrate surfaces, we address this topic in terms of reaction-diffusion model. In a previous study, it was found that charged polymer molecules, such as deoxyribonucleic acid (DNA), formed self-assembled patterns on mica and highly oriented pyrolytic graphite surfaces, which seem to be affected by the atomistic surface conditions. However, details of the pattern formation mechanism have not yet been clarified. Herein, we model interactions between molecules, such as DNA, and the symmetric surface structures using a two-component reaction-diffusion model. It is suggested that self-assembled patterns are strongly affected by symmetric surface structures, where a size difference between the atomic configurations of surfaces and adsorbent molecules are also taken into account. Although relatively large-size molecules may not directly reflect the surface structures, they provide interesting patterns resulting from the reaction and diffusion. On the other hand, small molecules, strongly affected by the surface structures, tend to clearly transcribe the surface patterns. Consequently, this study effectively explains the essential mechanism of the self-assembled pattern formation.

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Cavitation bubbles were generated by an underwater shock wave and formation of microjets in the collapse process were visualized by a high-speed camera. The directions of the microjets showed the same direction of the initial shock wave propagation. These results imply that the direction of the microjets were affected by the compression wave not expansion wave which was generated by reflection at an interface between water and air.

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The characteristics of sound sources are analyzed by Lighthill equation based on the direct numerical simulations of compressible isotropic turbulence to investigate the physical mechanisms of the noise from fine scale turbulence and their interactions with shocklets. We study mainly on the compressibility effects on the sound source terms in Lighthill equation by comparing various turbulent Mach numbers (M_<t0> = 0.1 to M_<t0> = 1.0), where the sound source terms are decomposed into the Reynolds stress, entropy, and viscous term. We show that the Reynolds stress term is the most contributer to the overall sound sources for all Mach number cases, on the other hand, the sound level of viscosity term is very small. Also the characteristics of sound sources are changed due to the generation of shocklets for high Mach number cases. For low Mach number flows, the Reynolds stress term and entropy term has positive correlation so that the overall sound level is intensified. However, for high Mach number flows, the overall sound level is weakened because the negative correlation between the Reynolds stress term and entropy term becomes stronger and they partially cancels out each other.

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In recent years, research of space plane and hypersonic airliner has been eagerly studied in the aerospace field, and a technique for measuring the temperature and pressure changes in the airframe surface is essential. Many researchers focus on the Temperature-Sensitive Paint (TSP) and Pressure-Sensitive Paint (PSP) as a technique for measuring them. In this study, we investigate a temperature measurement using Bakelite as visualization measurement method. It was possible to measure the stagnation temperature of the hemisphere model as the temperature distribution image in hypersonic wind tunnel based on the relationship between the temperature and the emission intensity of Bakelite.

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The instability wave generated in the transitional supersonic jet is investigated by linear stability analysis(LSA) and large-eddy simulation(LES). For the LSA, the analysis code for axis-symmetric flow based on shooting method is newly developed in this study, and the validity is first demonstrated using a benchmark test problem. Using this LSA code and LES results reported previously, the development of instability wave and transition behaviour are discussed in detail.

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A reflected shock wave by focusing reflector is simulated using the Navier-Stokes equations with the detailed oxy-hydrogen reaction mechanism. Into the tube which has focusing end wall, ignition successes around focal point under the no-ignition condition at the flat wall. The shock focusing is one of effective way of detonation initiation. However, the ignition mechanism from shock focusing is not clear. In this study, we aim to indicate the ignition phenomena induced by shock focusing.

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