A rapid expansion of moist air or steam in a supersonic nozzle gives rise to non-equilibrium condensation. If the latent heat released by condensation exceeds a certain quantity, the flow becomes unstable and a periodic flow oscillation occurs. In the present study, a numerical simulation of moist air flows in a supersonic nozzle was carried out using a special short duration supersonic wind tunnel, called a Ludwieg tube. The effects of the height of nozzle throat and initial relative humidity of the moist air have been shown for static pressure, condensate mass fraction and nucleation rate and total pressure loss numerically. As a result, it was found that the characteristics of flow with occurrence of condensation upstream of nozzle were largely different from that with occurrence of condensation in the nozzle.

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In recent years, the various processing ways using explosives have been studied in our research group. All the studies are related to the use of the underwater shock wave from the explosion of explosives in water. To suit the particular application, it is necessary to make the control of underwater shock wave to serve the demands of respective purposes. The purpose of this study is to explore the control of underwater shock wave by the use of detonating cord in a spiral configuration. The control of underwater shock wave includes the convergence technique of underwater shock waves and the technique to keep a constant pressure in the operating time The explosion of the spiral detonating cord will be expected to result in the convergence of shock available at the nearby of the spiral center. From this, the high shock pressure is generated. We use the high-speed camera to observe the converging process of underwater shock wave and pressure transducers to measure the pressure at the spiral center.

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The final aim of study is confirm a new technique that can crush frozen soil and/or ice on the farm by underwater shock wave generated underwater explosion of explosives. In the cold region, for example, North Japan, Russia, Norway, and Sweden, etc., this technique can makes carry out early sowing and having large harvest. Especially, in Hokkaido prefecture Japan, if sowing is carried out in April, we may be expected to have a 150% of harvest of ordinary season due to the total of the sunshine hours. At first, we carried out experiments, which use explosives and ice block. The process of of shock wave spreading in the ice solid was observed by using of the high-speed camera.

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This paper describes fundamental investigation to apply penetration of micro-jet to disintegrate microcapsules in Drug Delivery System (DDS). Deformation processes of a bubble near curved elastic wall by underwater shock wave were observed by optical shadowgraph method using high-speed camera. It is found that a bubble generates micro-jet toward wall and opposite side whose characteristics are affected by wall elasticity, wall curvature and a position of an initial bubble. Maximum velocity reaches 93m/s, which corresponds to 37MPa as water pressure. Changing wall elasticity, wall curvature and an initial bubble position can control penetration force by micro-jet.

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The supercritical liquid discovered in 1821,the specific character was known for many years. However, it began to be used industrially in Japan after the oil shock of the second half of the 1970s. Development of the process which extracts the high ingredient of added value focusing on fields, such as food and medical supplies, using the super-criticality CO_2 was furthered at first in Germany. The supercritical water attracts attention with a rise of the ocncem of the latest resources problem or an environmental problem. Moreover, the process development such as recycling, decomposition of dioxin and PCB and oilizing and monomerizing of a waste plastic have been active. In recent years, use of the woody biomass is briskly performed in Europe. Since there is the woody biomass abundantly, it tends to go into a hand. In this study, we proposed using the explosive welding technique for the development of pressure vessel and performed the numerical simulation.

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In the recently, it was showed that the airfoil model constructed with flat panels (based on double wedge airfoil) had the flight ability in the subsonic and transonic conditions. However there are few experimental aerodynamic data on the airfoil model constructed with flat panels in such flows. As the preliminary study, visualizations of the flow field around the double wedge airfoil model are performed with a conventional and sharp focusing schlineren method. The results show that the expansion and oblique shock waves are produced at the corner of airfoil surface on the double wedge airfoil model. Also, it is shown that this system has a capability for visualizing any cross section of transonic shock tube airfoil flow.

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The characteristics of supersonic jet noise from a Mach 2.0 nozzle with a thin-nozzle-lip thickness have been experimentally studied over a range of nozzle pressure ratios from 2.0 to 10.0. Acoustic measurements were conducted in an anechoic room providing a free-field environment. Shadowgraph technique was used as the tool to study qualitatively the shock wave patterns which are primarily responsible for shock related noise. The measured screech frequencies under overexpanded conditions are found to agree with Tam's theoretical results.

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To predict motions of both the micro and the macro free surfaces, we have developed a new method -called a particle/CIP hybrid method- that combines advection equations of the particle method with those of the CIP method. The new method was applied to a dam-break problem, namely, the fragmentation of a liquid column was predicted, and the prediction was found to agree well with experimental measurements. It was also used to predict breakup of a liquid film in a swirl injector used in automobiles. In this case, the predicted jet angle agreed well with the measured angle, qualitatively.

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The flow characteristics in counter-current flow in inclined pipe were examined experimentally. The classification of flow characteristics was done by visual observation, pressure gradient and liquid hold-up to characterize the flow regime. As a result, it was found that (1) the pressure gradient fluctuation was the biggest in churn flow, while it was almost constant in stratified flow, (2) the liquid hold-up at the onset of flooding agrees with the Lockhart and Martinelli correlation for the inner diameter 16mm. Furthermore, an experimental correlation to predict the frictional factor multiplier at the onset of flooding was proposed.

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Adiabatic experiments were conducted to measure pressure drop for single-phase liquid and gas-liquid two-phase flows through a circular microchannel with an internal diameter of 99.7μm. In order to study the effects of liquid properties on the pressure drop, aqueous solutions of ethanol with four different mass concentrations and distilled water were used as the working liquid, while nitrogen gas was used as the gas phase. For the single-phase flow experiments, the friction factor data were obtained for each working liquid used, and the data agree reasonably with conventional theory. Furthermore, early transition from laminar to turbulent flow was not observed over the present experimental flow conditions. For the two-phase flow experiments, pressure drop data were collected over a wide range of superficial gas and liquid velocities. The present pressure drop data could be well correlated by Lockhart & Martinelli type correlation irrespective of the working liquids tested, if an appropriate constant needed in the correlation is adopted.

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Nonlinear time series analysis is applied to gas-liquid two-phase flow in a vertical pipe of 42mm diameter in order to characterize complex dynamical behavior, and estimated fractal dimensions of time series are tested by the surrogate data method. The results show that (1) the point correlation dimension method with constant time window reconstruction is more reliable than the widely used Grassberger-Proccacia method with constant delay time reconstruction, (2) it is necessary to check the convergence for time series length, (3) the analysis using cross-sectional void fraction time series is more reliable than the analysis using pressure fluctuation time series.

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There have been derived the dual wings system in ground effect craft in order to improve the control stability on PAR (Power Augmented Ram wing) system. We have done to evaluate such aerodynamic performances as the coefficients of the lift and drag, its performance ratio for these constructions and arrangements. Those computer analyses have been introduced the reasonable tendencies on the relationship of those arrangements.

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Improved equations for evaluating the longitudinal stability in steady motion of high-speed for wing-in-ground-effect crafts were formulated. It was applied to special conditions for trend analysis and to an experimental WIG craft. The crafts may consist of arbitrary number of wings within or out of ground effect. The parametric studies on the effect of sizes and locations of the horizontal tails of the craft on the stability have given reasonable arrangements and tendencies.

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Aerotrain is a new transport system by using wing-in-ground effect. It has main wings and vertical side wings in the guide way. The vertical side wing which fixed at the main wing tip. The wind tunnel measured data show that the interaction of main wing and side wing is high in ground effect. The present work tried to raise the Aerotrain efficiency by using attached fillet in the sharp corner between the side wing and main wing. The results show that the optimum lift to drag ratio depend on the separation area by wing interaction and the separation area depend on the fillet shape and size.

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We examined the aerodynamic performance of the wiper with and without a spoiler by CFD. Numerical analysis was carried out in the condition of attaching the wiper on the windshield. Comparing with experimental results, it was clarified that this method was able to predict a down force and a resistance force with sufficient accuracy on practical usage. Furthermore, this paper describes the aerodynamic effect of the spoiler.

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As the maximum speed of Shinkansen trains increases, aerodynamic characteristics of pantograph have become an important subject of discussions. To maintain steady current-collecting performance, it is crucial to r educe the fluctuation of the aerodynamic lift force that works on pantographs. By combining computational fluid dynamics and numerical optimization techniques, we tried to optimize the pantograph configuration. This paper describes an outline of the method and the result of computation.

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The desertification is regarded as one of the global subjects in 21th century, because the desertified area has been estimated as approximately 6 million ha every year. In this paper, the flat sand surface is formed within an acrylic passage. The knife edged-plate is equipped at the tip of the passage. The saltation movement of the sand particle on the sand surface is observed in a uniform flow from a wind tunnel. Since the form of actual sand particle is not globular, the drag coefficient of the actual sand particle is determined by using the free-fall motion method in quiescent water. Instead of actual trees, the circular cylinders are set on the sand surface, and the sand surface form is observed.

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The suction flow from the upperside of a sphere on a flat plate is studied experimentally in order to lift the manganese nodules etc in the deep sea by a suction flow surrounded by a swirling jet flow. The experiments are carried out using air flow in the atmosphere. The lifting force exerted on the sphere is measured by using balances. The flow around the sphere is visualized using the tuft method. Several kinds of inlets are tested. It is concluded that the inlet of suction pipe with concentric annulus, which is composed of the outer pipe for swirling jet flow and the inner pipe for suction flow, is suitable for lifting valuable mineral deposits on the actual ocean floor.

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It is known that the flying characteristics of the golf ball are influenced by flying speed, rotational frequencies and the number of dimples, etc. In this study, the pressure acting on a test spheres is measured using a pressure transducer, and the flow visualization around the test sphere is performed applying the spark tracing method by changing the number of dimples and Reynolds number, The number of dimples is changed from 0 (smooth) to 504,and the diameter of the sphere is 42.6mm. Reynolds number is changed from 4.23×(10)^5 in a uniform air flow. A further, a three-dimensional aerodynamic characteristic of the golf ball is clarified by using the CFD (LES model). From the results, the separation point, pressure distribution and the flow pattern of the wake flow became clear.

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The sphere is a basic configuration of three dimansion body, and the drag has already been already researched. Drag coefficient is steady by about 0.44 and this paper is described on the change of the fluid force and flow pattern on a sphere in the critical range of the Reynolds number. In the critical region the flow changes into the complexity because it is a transition region from the laminar to turbulent flow. In the critical region the fluid force and pressure distribution were measured. in uniform flow in the Reynolds number range of 1.0×(10)^5∿4.1×(10)^5. From these results, in the critical region of Reynolds number the separation point does not become symmetrical, and the flow becomes unsteady in the upstream of the separation point.

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It has been focused on the study of fluid mechanics at the low Reynolds number (about (10)^2<Re<(10)^4), which is animal flight area. It is necessary to examine the aerodynamic characteristics of the wing to clarify what kind of wing shape is suitable for the flight at this region. Thus, we planed to survey the wake flow field produced by the wing section of NACA0012 when the angle of attack changes suddenly using hot-wire anemometer at Reynolds number of 1000. Moreover, we drew some diagrams of instantaneous velocity in the wake of wing since the angle of attack has changed impulsively. As a result, we found that the wake is rocked periodically by upwash and downwash.

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The performance of airfoils operating at chord Reynolds numbers below (10)^6 becomes more important with relation development remotely piloted vehicle, sailplanes and Mars airplane, etc.. In this study aerodynamic characteristics of a flat plate airfoil operating at a chord Reynolds number range of Re=2.0×(10)^4&acd;5.0×(10)^4 was examined in a low-speed low turbulence wind tunnel. A flow visualization was made at a Re=2.0×(10)^4. The lift and drag forces on the airfoil were measured by a three component force balance. Smoke was used to visualize the flow patterns around the airfoil. The result of this research indicated that reduction of flat plate thickness improved the performance of the airfoils.

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It is known that an oscillating airfoil can produce a driving force through the generation of a reversed Karman vortex street, and this can be expected to be a new highly effective propulsion system. A heaving airfoil model was made and it was operated within a water channel. The wake formation behind a heaving airfoil was visualized and a dynamic thrust force was measured using a 6-axis force sensor based on force and moment detectors. We have been examined various conditions such as reduced frequency and amplitude in NACA 0010 profile. The results showed that a thrust coefficient increased with Strouhal number. We also presented the experimental results on the unsteady fluid forces of a heaving airfoil at various parameters.

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3 dimensional wake structures behind rectangular flat-plate wings with aspect ratios of 0.1&acd;1.0 have been investigated using Laser Doppler Velocimeter and yaw-probe. Flow details, such as vorticity vectors and vortex lines in the wakes, have been analyzed for the 5 typical flow configurations (PS-1&acd;PS-4,FS), which were classified in the previous report from the measurements of aerodynamic characteristics and surface flow visualization. Trailing vortices are clearly formed for flow configurations, PS-1 and PS-2. Ring-type vortices are shed for FS. Vortex structures for PS-3 and PS-4 appear to be mixed types of trailing vortices and ring-type vortices.

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This study focuses on the aerodynamic characteristics of flexible wing, especially the relationship among the shape of air intake, surrounding flow and inner pressure of the wing. The improvement of the shape of air intake and pressure distribution from he standpoints of aeromechanics will contribute to raise flexible wing gliding ratio. As the object for measurement, we had prepared rigid and flexible wing (these wings have same wing cross), and simplified intake model. At this moment, our experimental equipment is composed of accurate pressure gauge and visual image instrument and hot wire anemometer. By this experiment, it became clear that the pressure distributions of these two wings were completely different. We also confirmed the particularity of surrounding flow that has air intake.

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Fractal is one mathematical method of analysis of complicated system which complication can be described by dimension of fractal. Piezoelectric pump is a new type fluid machine, which is apt to a wide aspect of applications in such scopes as medical treatment and micromechatronics, for it's realizable to simplify and minimize its structure. The character of the noise from this new pump, which affects it deeply, however, has not been studied and reported. Firstly, there is a judgment in this paper that the noise from piezoelectric pump presents fractal, and then the relationship between the noise level and driving frequency is explained based on the theory of fractal.

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The radiation of impulsive sound, i.e., pulse, from a flanged cylindrical duct at the open end is investigated using a high accuracy 7-point optimized DRP scheme. The computed result shows that an expansion wave near the open end on the inner wall of duct is produced immediately after the compression pulse radiates from the open end. The strength of the radiated wave is closely related to the pressure gradient of the wave near open end. The present results also clarify that the length of pulse significantly changes the characteristics of wave pattern.

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We have measured the radial distribution of the jet axial velocity except for the core part near the nozzle of the water jet by using a laser-Doppler-velocimeter without any tracer. Experiment data showed that the ratios of the maximum velocity to the theoretical velocity calculated from Bernoulli's euation and the mean velocity to the Bernoulli's theoretical velocity were in the range of (0.93&acd;0.95) and (0.78&acd;0.87), respectively.

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A new primary standard for hydrocarbon flow measurements has been constructed at National Metrology Institute of Japan. The facility is designed to calibrate hydrocarbon flowmeters from 50mm to 150mm in diameter, at flow rates from 3 to 300m^3/h by using light oil and kerosene as the working fluids. The calibration procedure is based on a static-gravimetric method with flying start and finish. As a result of introducing a newly developed diverter system and other sophisticated equipments, the expanded uncertainty of the calibration has been proved better than 0.03% for volumetric flow rates, which enables calibration service with the smallest uncertainty in the world. The dominant sources of combined uncertainty of flow rate are uncertainties in the measurements of the mass of liquid in the weighing tank and the density of the liquid through the flowmeter.

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Recently mixing technology is important to chemical engineering, food engineering, bio engineering and etc.. However, mechanism of emulsification has not been fully understood. In this study, breakup processes of oil droplets in water were visualized to clarify the emulsification mechanism using an emulsifying equipment with homogenizing mixer. The effect of flow generated by a rotating impeller on atomization was investigated. A PIV technique was used to evaluate the flow field around the homogenizing mixer. The experimental result showed that there were three different kinds of break up processes of oil droplets in the vicinity of the impeller. In addition, it was observed that the flow around the impeller was inclined in its rotating direction to the vertical axis.

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The past studies have reported that, in the flow around a circular cylinder at Re=15,000,a large drag reduction can be achieved by appropriate rotational oscillations to the circular cylinder. But concerning the drag reduction effect n the lower Reynolds number range (Re<3,000), there is discrepancy among the past studies. In the present study, three-dimensional turbulent simulations with the LES model were carried out in order to unveil the mechanism of the drag reduction effect of the flow around a circular cylinder with rotational oscillations at Re=2,000.

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Flow around a rectangular cylinder in oscillatory flow was studied by a numerical simulation using a finite-volume method. The computations were carried out through Keulegan-Carpenter number (KC) in the range of 3≦KC≦12 at Stokes number (β)=95 in the cases of D/H=0.4,0.6 and 2.0 such as in the cases of circular and square cylinder. For D/H=0.6,at KC=12," transverse-vortex street" observed in circular cylinder was also predicted. It was found that at the low KC number the change of spanwise correlation of transverse force corresponds to the ones of longitudinal vortices along the span.

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Flow-induced in-line oscillation of a circular cylinder has been experimentally studied by free oscillation tests in a water tunnel. The cantilevered cylinder models were supported elastically by a plate spring so as to oscillate only in the in-line direction. An end-plate (=3d) was fitted to the free end of the cantilevered cylinder to examine the influence f end-effects on the flow. Air-injection pipes were set at 300mm (=15d) upstream before a cylinder model to examine the influence of bubbles. The response characteristics of cylinder with aspect ratio of 10 in bubble flow shows only one excitation region at Vr=1.1 to 3.2 and the oscillating amplitude is smaller than that is uniform flow at Vr=2.0 to 3.2. While a cylinder with aspect ratio of 14 in bubble flow has two excitation regions. The amplitude in the second excitation region (2.5<Vr3.0) is smaller than that in uniform flow. The response characteristics of cylinder with an end-plate in bubble flow shows two excitation regions near half of the response velocity. The amplitude in second excitation region (at Vr=2.5 to 3.3) is smaller than that in uniform flow.

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This paper describes the flow characteristics around circular cylinder with arc grooves. In this study, cylinders with arc grooves of different depths are used. There are 32 grooves in the direction of the axis. Three pressure holes inside the grooves and one between a pair of grooves are prepared in order to measure the surface pressure around the cylinder. Drag and lift coefficient are calculated from the pressure distribution measured in the range of Reynolds number Re=0.35×(10)^5&acd;1.8×(10)^5. And the velocity distributions on the surface of the cylinders are measured by means of the hot wire. From these experimental results, the change of drag and lift coefficient to the depth of grooves and Reynolds number of the cylinder with arc grooves and effect of the grooves in decrease of drag are developed.

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In this study, the flow features of vortex shedding from a square cylinder forced-oscillating in the in-line direction were investigated by use of flow visualization technique at the Reynolds number Re=1004,with six kinds of amplitude ratio and the range of oscillation frequency ratio from 0.0 to 12.7. As a result of the experiments, six kinds of representative flow patterns were observed. In the case of the smallest amplitude ratio 2a/h=0.0353,there was not an influence of the cylinder oscillation to the mean vortex shedding frequency. It was found that when the oscillation amplitude ratio 2a/h becomes large, the frequency ratio which the lock-in occurs to becomes small and even if the cylinder oscillation frequency is smaller than the natural Karman vortex shedding frequency, The lock-in phenomenon arises. The flow pattern map in the lock-in region was shown.

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The space allowed for mounting a torque converter on front-wheel-drive cars has been increasingly reduced in recent years due to the adoption of larger engines with more cylinders and the higher functionality achieved for transmissions, including the addition of more speed ranges and greater use of CVTs. This situation has dramatically heightened the need to reduce the torque converter's axial length. This paper presents a numerical analysis of the fluid flow state and loss characteristics in a new torque converter with a flatter design. The results make clear the effect of the flatness ratio on hydrodynamic performance. Measures for reducing torque converter loss are examined on the basis of the analysis results, and their effectiveness is evaluated.

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Today, environmental problems are shouted large, and something that the energy of nature can be effectively used even if it is low efficiency like the wind mill is reviewed. The jet pump is reviewed from the advantage such as being able to use the energy of nature effectively though is comparatively low efficiency. Therefore, this study did the study concerning the hydraulic transportation of the solid particle using the characteristic of the water type jet pump. The performance of the water type jet pump was investigated by changing nozzle to throat ratio from 0.27 to 0.67 and the driving pressure from 0.15 to 0.50MPa. Afterwards, the influence on the performance of the jet pump when the particle was transported in the maximum concentration was examined.

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Biodegradable and mineral oils were assessed experimentally using a swash plate type axial piston pump. Six kinds of synthetic ester type biodegradable oils, three types of biodegradable vegetable oils and the mineral oil with the viscosity grade of 46 were prepared. The discharge pressure was set at 20MPa and the oil temperature was kept at 80℃. The pressure, temperature, flow rates and the torque were monitored during the continuous operation up to 300 hours. The performance of the pump was evaluated at every 100 hour and the physical and chemical properties of the oils were analyzed. In conclusion, i) The changes in viscosity of the vegetable oils were largest; followed by the synthetic biodegradable oils and the mineral oil, and ii) The increases in the viscosity, total acid number and the color were marked while the changes in the pump performance were less shown.

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This paper presents the result of static pressure distribution measurements on the surfaces of endwall and rim-side wall of a nozzle ring with a rib behind the blading. The measurements were performed with an axial flow model turbine that consists of a nozzle ring and a rotating disk equipped pin blades, and with a constant disk cavity gap. The velocity ratio of the rotating disk to the main flow was changed under a constant blade Reynolds number. The pressure distribution characteristic to discuss the possibility of the main flow enrolment to the disk cavity was clarified through the study.

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A new valve-less micro-pump was developed in this study. The pump is composed of a variable volume pump chamber with a piezoelectric actuator and a fluid conveying pipe connected to the pump chamber with an angle through the pipe. A net pumping was realized in the asymmetric flow profiles in the asymmetric configurations of the pump chamber and fluid conveying pipe. The actuator was driven by using a sinusoidal 250V AC signal at frequencies from 8 to 25Hz. The frequency response of the pump to the driving frequency showed that there exists an optimal driving frequency for the pump geometry. The maximum flow rate was 1.3ml/min at 0Pa under the optimum frequency, whereas the total head rise through pump was 600Pa at zero flow rate for water. The net pumping of fluid in valve-less micro-pump was confirmed by numerical calculation using commercial CFD software CFX-TASCflow.

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A purpose of this study is to investigate the effect on drag reduction in a circular pipe flow by means of the wall coated with nonwoven fabric. Five types of nonwoven fabrics used in these experiment are an electret ones made of polypropylen. Friction factor was measured for various Reynolds numbers (8000-40000) against tap water and air, and these results were compared with those obtained by a circular pipe without nonwoven fabric. The following results were obtained : The maximum drag reduction was estimated to be 30% for the tap water and 6% for the air. It was proven that the wall coated with the nonwoven fabric is effective to reduce the drag in the circular pipe flow.

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We investigated the drag reduction phenomena on highly water repellent surfaces, which have micron to sub-millimeter order of projections at several intervals of the same order. The most significant drag reduction in the present work was achieved on the surface of the largest structure among those of the constant concavo-convex ratio. The ability to hold the air layer in water depends on both the size and the ratio of concavo-convex structure. The water-repellency of these surfaces in bulk water didn't match that estimated from the contact angle of water droplet on the surface in ambient air.

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Pressure drop through a porous material set in a circular tube was measured experimentally using air as a working fluid. A fiber was constructed by a thin copper wire (d_w=0.5mm). The porosity ε was from 0.98 to 0.999 and Reynolds number from 2000 to 1500. Usually, the characteristic length of porous material is wire diameter or particle diameter. However, in porous material with high porosity the hydraulic length including tube wall and porous material was proposed as a characteristic length in place of wire diameter.

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The Air Turbo Ramjet (ATR) Engine is considered to be one of the propulsion systems for Space Planes. The Precooler is one kind of the heat exchangers and a key technology of the ATR Engine. The Precooler reduced the compressor work by increasing air density. It, however, produces the inlet distortions of total pressure and temperature at the compressor inlet. To clarify the distortions, the Precooler is modeled as elbow ducts with tube banks and the distributions of the velocity are measured. The results show that the velocity becomes fast in the inner region and slow in the outer region for the elbow ducts with tube banks, opposite to one for the elbow duct without tube banks.

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The pseudo direct numerical simulation, extended to boundary fit coordinate, has been carried out for fully-developed turbulent flow though triangular rod bundle, on the assumption of infinite array. The purpose of this work is to verify the method to be applied for rod bundle thermal hydraulic analysis. The turbulent Reynolds number, based on the friction velocity and the hydraulic equivalent diameter, is 600. The good results for the mean velocity profile, and the wall shear stress distribution are obtained.

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Numerical simulations are performed using a deformation grid to investigate a propulsion mechanism of deformed hydrofoil profile. The shape of the hydrofoil profile was chosen by NACA65 type hydrofoil. Hermit and transfinite interpolations are used to generate internal grid points. These method can eliminate the overlaid grids at large amplitude. A fractional step method using implicit numerical viscosity is adopted for computational efficiency. We compared five kinds of thickness about difference of propulsion power and it's efficiency. And it is clear that propulsion efficiency increases with decreasing thickness.

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A numerical method for moving and deformation grid in the three dimensional flow is developed. The new arbitrary Lagrangian-Eulerian method considerd grid acceleration is constructed. The scheme is fourth-order accurate in space and uses the momentum equations for the velocity coupled to a Poisson equation for the pressure. The fourth-order consistent scheme is applied to the convective terms in the Navier-Stokes equation. In this investigation, the flow around periodic bending flat plate is computed. As the results of this investigation, drag and lift force around deformating plate can be estimate. It is also demonstrated that fractional step method are required to advance the solution from n to n+1 instead of the rezoning method.

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Three-dimensional numerical calculations have been performed on liquid-metal magneto-hydrodynamic (MHD) flow through a rectangular channel in the inlet and outlet sections of a magnetic field. The continuity equation, the momentum equation including the Lorentz force term and the induction equation have been solved by the finite difference method. The pressure drops in the inlet and outlet sections of the magnetic field becomes larger than that in the fully-developed region inside the magnetic field. The pressure drop in the outlet region becomes larger than that in the inlet region of the magnetic field. A pressure recovery along the flow axis, which is shown in the inlet section of the magnetic field, is not seen in the outlet section of the magnetic field.

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The principle of alleviation of "micro-pressure wave" is to decrease the pressure gradient of the compression wave generated by a train entering a tunnel. "Optimum nose shape" minimizes the pressure gradient under the given conditions of train cross-sectional area and nose length. After reviewing the results of numerical optimization of the nose using CFD, we performed aeroacoustic analysis. As a result, the characteristics of the optimum area distribution and the influence of the offset of the train axis was clarified.

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Experiments are performed using flow visualization to investigate variety of flow pattern appearing in the flow around a disk in a casing. Small flake of aluminum power is used. Stability ranges of Reynolds Number are obtained from many experiments.

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