The objective of this study is to develop a prototype of polymer- abrasive-water suspension jets (polymer -AWSJ) for micro-cutting of some materials. There are 3-systems as method which supply abrasive into water jet. The bypass system is excellent system for economy and simplicity of system in Abrasive Water Suspension Jets(AWSJs). However, it is demerit the abrasive concentration in jet decrease with jetting time. Experiment for the abrasive concentration in jet is conducted and as the results, experimental results for the abrasive concentration in jet agree with theoretical equation. It is shown that the abrasive concentration in jet is stable by changing the mass flow rate of bypass line.

The objective of this study is to understand the role of Sakafune-ishi as the fluidic device. Sakafune-ishi is the stonework which developed in Asuka period. The geometry of Sakafune-ishi looks like flip-flop device. We idealized the Sakafune-ishi as fluidic device. The experiment to observe the flow from output was carried out. In this experiment changed the combination of B, C, D, E, and H port, observed State of the outflow of water. AS a result, in this model the water simultaneously from all outflow ports was discharged. Therefore, it was found that the flow of water is not switched.

Cell separation is one of the most important technologies for future medical applications. New strategies to separate viable cells are needed to develop novel cell therapy which is a new medical treatment as a low invasive technique. Hepatocyte transplantation is one of the cell therapy for infants with metabolic disorder. It is expected to alternative treatment of liver transplantation. Preparation of the hepatocyte is important to improve the efficiency and the safety of the hepatocyte transplantation. In this study, the new strategy for cell capturing and separation method with the Dean in the liquid-liquid interface of two phase flow is proposed and confirmed experimentally.

Nasal continuous positive airway pressure (Nasal-CPAP) is frequently used in the care for the preterm neonates．I have developed a nasal CPAP device with bypath (BNCPAP) of vertical allocated type with additionally compiled HFOV function. In previous report，I performed the performance test of the BNCPAP device which I produced. In the present report， I perform a performance prediction about 7 calculation models that increased duct exit of model. BN-CPAP device which widened exit duct width lost CPAP pressure increase at expiration, and it became clear to have the new device performance that CPAP pressure decreased for increase of MAP.

The velocity measurements of the jet flow issuing from the pentagonal duct with and without the synthetic jet were performed by using hot wire probes and the constant temperature anemometer. The jet diffusion was investigated by analyzing the velocity distributions. In order to excite the share layer of the jet, the synthetic jet was spouted from the actuator set on the outside of a vertex of the duct exit at 45 degree angle with respect to flow direction. As a result, it has been found that the jet diffusion adding the synthetic jet with high frequency in xOz -plane is promoted due to the turbulent intensity becomes large in the vicinity of the jet center axis in the upstream region and in the shear layer in the downstream region.

A reactor core isolation cooling (RCIC) system of the Fukushima Daiichi Nuclear Power Plant Unit 2 is continued to operate even after the loss of power supply. As a result, the water injection to the reactor core has been carried out for more than 70 hours from the earthquake. Even though the control power is lost, the factors that water injection by the RCIC is continued is still unknown. On the other hand, from the results with the MAAP analysis, the RCIC is speculated that had been driven by two-phase flow of water and vapor. Therefore, in order to contribute to the clarification of the unexplained events related to the RCIC of 1F2, void fraction distributions based on water and vapor volumetric rates in the RCIC turbine has been evaluated analytically. From the present study, it was found that the torque applied to the turbine increases with the increase of accumulated water and prevents the rotation.

We have developed a portable flow visualization device system, which focuses on the cost-effectiveness, easy handling and safety in a real environment. In our previous study, the method of generating a sheet light using rotating multiple light sources is proposed and successfully applied to some flow visualizations. However, it is found that the amount of light is insufficient to reveal the structure of the flow. In this paper, our previous method is improved to raise the amount of light by means of increasing the number of the light sources. Several flow visualization experiments are carried out to show the performance of the proposed method.

In this work, the effects of liquid viscosity on flow patterns, gas slug velocity, liquid slug length, void fraction and friction pressure drop of two-phase flows in a horizontal circular microchannel with an inner diameter of about 530 μm have been reported. In the experiments, as the working fluids, nitrogen gas for the gas and seven kinds of liquids for the liquid mainly with different viscosity were used. Liquid kinematic viscosity of working liquids were ranging from twice to 20 times than that of distilled water. The gas slug velocity for the case of nitrogen distilled water coincided with homogeneous flow velocity and for high viscosity liquids it gave higher values than that of Hughmark's equation.

In this work,the effects of transition on flow patterns,gas slug length and friction pressure drop of two-phase flows in horizontal circular microchannel with an inner diameter 100,150,250 and 518μm have been reported.In the experiments,as the working fluids,nitrogen gas for the gas and distilled water.

Electrification between PMMA particles and aluminum pipe during fluidization have been investigated for different Initial water content of the surface of the particles. The dried particles moved strongly up and down immediately after fluidization while the channeling and the slugging flows were observed for humidified ones. Although the dried particles had initially negative charge, the particles had positive charge below the initial position of the packed bed because of the emission of water content on the particle surface during fluidization. The humidified particles had negative charge even if the emission of water content could be occurred. When the preservation interval of the dried particles in the paper bag got longer, they had negative charge. As the surface state of the particles was changed by adsorption of water little by little in the paper bag, the contact potential difference between the PMMA particles and the wall of the aluminum pipe changed.

To investigate the physics of the gas and particle phase in the particle laden turbulent flows, the velocity variations of gas and particle phases of turbulent boundary layer flows are simultaneously measured by the particle image velocimetry (PIV). Changing the particle size, and taking the conditional average based on the velocity of the gas phase and particle phase, the effects by the behavior of the particle and the particle size on stresses in the particle phase are investigated. It is found that rising particle greatly contributes to the Reynolds shear stress of the particle phase.

The generation of the three-dimensional twins vortices behind soccer balls wake was confirmed by 3D-Dynamic PIV measurement and the fluid forces occurred on the balls were measured simultaneously. As a result, it was confirmed that the direction of the jet flow between the three-dimensional twin vortices was opposite to the direction of fluid forces.

The purpose of this study is to elucidate an unsteady phenomenon related to a control valve in the hydraulic equipment. Experiments on a control valve plug model with no support were conducted by using a Magnetic Suspension and Balance System (MSBS). The fluid force and the differential pressure between upstream and downstream acting on the valve model was measured by steady–state tests and oscillating tests. The fluid force and the differential pressure changed to depend on the flow rate and the gap distances. The flows are quasi-steady at frequencies 0.25 ~ 1.0 Hz by comparing the results of steady–state tests and oscillating tests. These results show that the evaluation of a control valve plug with MSBS will be beneficial to design the hydraulic equipment.

In large plants, an accident occurs that the piping system vibrates and finally leads to destruction. The fluid flowing through the pipe is regarded as one of the causes, and two types of phenomena“Acoustic Induced Vibration ”and“ Flow Induced Vibration ”are generated. The natural frequencies of the pipe and of the fluid column in it was examined by modal analysis of ANSYS. In the experiment, the pipe and the fluid column vibrate each other at the mode anticipated by the calculation. At resonance frequency, the amplitude of vibration becomes large as the acoustic power of source increases.

The behavior of the unsteady necklace vortex formed in front of a rectangular flat plate with an aspect ratio of 2 vertically standing on the flat ground wall on which the laminar boundary layer develops was investigated by using a dynamical visualization and the time series PIV measurement. As a result, it was revealed that the necklace vortex pattern could be classified into five types of 2-, 4- and 6-laminar necklace vortex systems, and two unsteady vortex systems such as oscillation and amalgamation behaviors. The boundary of the necklace vortex patterns depends on Reynolds number and the boundary layer thickness. The turbulent intensity increases rapidly in the amalgamation.

In a narrow tube water columns could be maintained with surface tension, and they could be transported to height only with very slow speed, otherwise they were divided into a lot of drops of water. The limited values of velocity were found experimentally at various surface tensions and with various diameters of tube. With a compressed air tank and regulator, air of low pressure and low flow quantity was supplied to transport a water column upward. The methods of connecting a water supply pipe, an air supply pipe and a water column transportation pipe were studied for next water column to be supplied automatically after a water column flew into a collection device. It was confirmed that water could be transported to the height of 60m with this system. This means that we can transport water to height automatically and continually, if we have a bicycle inflator, a pressure vessel and a long narrow tube.

By using the phenomena that the concentration of particles decreased by passing through branch pipes, a rotating filter was developed to remove particles in two phase fluid. In this report, filtering effects about water containing 8.5 μm aluminum particles were studied. It was found that the concentration of particles of rotating filter output was less than the theoretical values, and that a lot of aluminum particles were collected in a rotating filter. The principal of this filter could not be explained by the phenomena mentioned above, and it could be explained as follows. As the number of rotation increased, a boundary layer containing a lot of particles was formed on the rotating filter. As the quantity decreased, the rotating filter inhaled liquid from the boundary layer containing high density particles. In the rotating filter, a forced vortex was formed. Because of high specific gravity, aluminum particles were hard to move to the outlet at the center of the rotating filter, as the number of rotation increased and the quantity decreased. So ideal filtering device could be formed, which collected particles from original fluid and drained out fluid with lower concentration of particles than original fluid.

We often perceive odors of smoking at seats for non-smokers of cafés and restaurants. A new ventilation system was developed by using the knowledge that neither flow separation nor backward flow could occur in case of increasing velocity distribution near walls by using 1/10 models⁽¹⁾⁽²⁾. In this paper, the effects of the system were examined by using an actual scale model, and it was confirmed that the system could remove smoke promptly, and that unsteady flow prevented smoke from staying in the wake of column. The conditions when residence time of smoke was the shortest were found as follows. The value of Strouhal number was about 0.3, and the ratio of flow time and period was about 0.5.

When a cylinder rotating around horizontal axis was put on the turntable rotating around vertical axis, and when a standstill device to trim the powder attached to the cylinder wall was added, wheat flour and aluminum powder could be stirred well. And starch and aluminum powder could be stirred well, if the axis of the cylinder was set apart from the horizontal axis of rotation with distance of several mm. But starch and powder of aluminum oxide could not be stirred well with such method. The device to trim the powder attached to the cylinder wall was turned freely and was stopped turning momentarily in every rotation, the powder was vibrated and stirred well. The effects were so strong, it was found unnecessary to rotate the cylinder around vertical axis.

The accidents that a truck overturns by a storm have occurred frequently. Shapes of the container of truck hard to overturn were studied. The moment of force caused by side wind around tire of truck model was measured by using wind tunnel and device made with 3D printer and momentum coefficients were found. It was found effective that the corner of the roof of container was rounded off.