In order to reduce not only the emission of carbon dioxide which is known to promote global warming but the consumption of fossil fuel gas turbines are always requested to be highly efficient. In the turbine section, highly efficient is achieved by increasing the turbine inlet temperature. Film cooling is intensively used to cool the turbine section. And film cooling performance is improved by varying the various parameters cooling holes shape, the angle, etc. This paper details the cooling hole compound angle to inhibit Counter Rotating Vortex Pair (CRVP), which invite the cooling performance degradation. Reynolds-Averaged Navier-Stokes simulations have been conducted for the case of compound angle = 0, 30, 60 [deg]. According to results of numerical analysis, the cooling performance of compound angle = 30 and 60 [deg] is better than that of compound angle = 0 [deg].

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Brayton Cycle of CO_2 has been recognized as an attractive new method for power generation. In this cycle, Supercritical CO_2 is compressed and heated beyond the critical pressure and temperature. Transonic flows through a compressor cascade are investigated under the supercritical condition by our numerical method coupled with the condensation model. The condensation by the temperature decreasing is found near the leading edge.

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Icing simulations are of importance in the development of aircraft and jet engines. Currently, icing simulations are performed in the Eulerian framework. On the other hand, we employed the MPS method which is a mesh-free method in the Lagrangian framework. In addition, the MPS method can predict liquid interface if its deformation is large. Our final goal is to perform the three-dimensional icing simulation on NACA airfoil. In the present paper, we perform icing of one droplet as for a preliminary. The obtained result indicates that the three-dimensional icing simulation using MPS method reproduces the complex ice shape even in the two-dimensional simulation. If angle of attack is large, splash mass computed by the MPS method shows good agreement with that by the previous studies.

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Unsteady wet-steam flows through a three-stage low-pressure steam-turbine model developed by Mitsubishi Heavy Industry are numerically investigated. We solved compressible Nervier-Stokes equations coupled with nonequilibrium condensation models and SST turbulence model. Numerical results obtained by assuming single passage and multi passage are compared with each other and the effect of the blade number on unsteady wet-steam flows in the real low-pressure steam turbine is discussed. Numerical results are also compared with the experimental data.

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This research investigates experimentally the effect of forward-swept design on the performance of the rotor blades in a low-speed, single-stage axial-flow compressor under one-per-rev type inlet distortion. In addition to stall tests in clean inlet flow condition, full-annulus area traverse measurements are conducted at the inlet and exit of both the radial rotor and the swept rotor at their respective near stall points in distorted flow condition. The swept rotor shows throttle margin increase of 8% compared to the radial rotor in distorted inlet flow. In the case of swept blades flow, measurements show that a stalled region forms locally in the tip region at the exiting edge of the distortion, and vanishes as the rotor moves away from the edge. Since the forward-swept rotor causes a spanwise flow redistribution toward the tip, the tip stall cell can be vanished moving around the circumference.

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Small-sized axial fan is used as air cooler for electric equipment. But there is strong demand for higher power of fan according to the increase of quantity of heat from electric devices. Therefore, higher rotational speed design is necessary, however it causes the deterioration of efficiency and increases the noise. Then, the adoption of contra-rotating rotor for small-sized axial fan was proposed for the improvement performance. In the present paper, the unsteady numerical analysis was conducted to investigate the performance and internal flow of contra-rotating small-sized axial fan rotors at the design flow rates. Further, the appropriate blade row distance of the contra-rotating small-sized axial fan was clarified with the unsteady numerical analysis results.

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The contra-rotating rotor is effective for the down-sizing of the pump system. In the present study, since the reduced speed design of the rear rotor has been found to bring about higher hydraulic efficiency for contra-rotating axial flow pump, we design several rotors with different specific speeds of rear rotor to further examine the influence of rotor specific speed on hydraulic efficiency. It is found that the efficiency of rear rotor becomes better as the reduction of specific speed of rear rotor, whereas the efficiency of front rotor is deteriorated nevertheless of its constant specific speed, finally resulting in the maximum total efficiency at the moderate specific speed of rear rotor. Moreover, even though the rear rotor reveals the better efficiency with its reduced specific speed, the strong secondary flow is observed on the suction surface of rear rotor blade. More appropriate blade design seems to be necessary for further improving performance with the reduced specific speed design of the rear rotor.

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In this study, the effect of the rotor axial offset and impeller-diffuser gap (smaller gap or larger gap) on the performances and the unsteady thrust forces of a three stage centrifugal pump were experimentally investigated. The change of the gap was realized by cutting an impeller diameter. By cutting the impeller diameter (larger gap) the positive slope of the head performance curve was observed in lower flow rates than 20% of design flow rate, while it was not observed with the smaller gap. In the flow rate range with the positive slope, the distinct pressure fluctuation with low frequency (14% of impeller rotation), measured at the inlet throat of diffuser vane, could be recognized, which was found to be caused by the diffuser rotating stall with 1 cell. The unsteady radial thrust force caused by the diffuser rotating stall was observed at the same time. The rotating stall was more significantly observed in the 3rd stage, which was probably because the test pump system employed the balancing drum for the thrust balancing device; the effective flow rate is larger in the 1st and 2nd stage diffusers than the 3rd one due to the leakage flow to the balancing drum just upstream of the 3rd stage diffuser.

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The CFD analysis was conducted to investigate the effect of impeller tip clearance on internal flow in a centrifugal compressor with vaned diffuser. In previous studies, the leading-edge vortex (LEV) was produced near the diffuser leading-edge and the growth of the LEV deteriorated compressor performance. In addition, the LEV was enlarged by the tip-leakage vortex. In case of using impeller without clearance, corner vortex produced on pressure side of the impeller plays a similar role to tip-leakage vortex. Furthermore, the LEV develops and forms a huge flow blockage within diffuser passages at off-design operation, considering impeller tip clearance. However, the flow fields in diffuser passages were stable because the LEV was stationary on the suction side of the diffuser leading-edge in analysis of using impeller without tip clearance. Therefore, the tip-leakage vortex was considered to be the cause of diffuser stall at off-design operation.

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We have developed a new micro air pump, which is driven by a single piezoelectric actuator. In this paper, its pumping mechanism is studied numerically. It is shown that the phase difference between two vibrating disks in the air pump, a diaphragm driven by a piezo actuator and a disk vibrated passively by pump room pressure, plays a critical role to generate net flow rate. The phase difference is set to be a desirable value by adjusting the thickness of the passive vibration disk.

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Ventricular assist devices (VAD) are receiving a lot of attention as a cure for heart failure. The cure for serious heart failure is possible by a ventricular assist device or a heart transplant. VAD is used as a bridge to the heart transplant. Furthermore, the use of VAD as destination therapy is expected. Therefore, VAD is a promising device as future heart failure treatment. However, VAD has a lot of problem with practical use, such as anti-thrombosis, anti-hemolysis, durability and safety. And, expansion of the application range by the further downsizing is demanded. In this study, the semi-open impeller for the micro centrifugal pump with 24mm impeller diameter was adopted. In the present paper, its performance and internal flow condition are investigated based on the numerical analysis results.

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Rotordynamic force and moment can cause shaft vibrations in pumps and water turbines. The rotordynamic fluid force which acts on back shrouds of the impeller and runner generates the rotordynamic fluid moment, and it can cause whirling motions of overhung rotors. A test facility in which the back shroud was modeled by a rotating disc was made and the whirling motion of the rotor due to the rotordynamic fluid moment could be observed. It was found in computations that a cause of the rotordynamic fluid moment can be explained by an inertia of a radial clearance flow in ranges of higher whirling angular velocity ratios in which the flow has stronger unsteadiness and a pressure loss in the seal at the periphery of the disc in all ranges of whirling angular velocity ratios.

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Unsteady flow field inside a torque converter model made of acrylic resign is measured using a dynamic stereo PIV system. The index-matching technique is used to visualize the flow field in the gap between an impeller and a turbine. The rotation speed of the impeller is 250rmp while those of the turbine are 25rmp and 150rpm, giving the speed ratios of 0.1 and 0.6, respectively. The instantaneous velocity maps obtained from the stereo PIV analysis are phase averaged according to the relative angles of the impeller, the turbine and the stator. Those phase averaged three-component velocity maps are reconstructed to visualize 3-D characteristics of this complex unsteady flow field.

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We study the internal flow of Hard Disk Drives (HDDs). The flow induced by a stack of rotating disks exhibits complex behavior, which is supposed to be responsible for the performance and reliability of HDDs. We built a HDD model consisting of non-axisymmetric enclosure equipped with arms and a shroud opening. Flow visualization was performed using a scaled experimental model with all the parts made of a transparent material. An application of refractive index matching to the working fluid enabled clear view of the whole flow field with minimum optical disturbances. Velocity fields in planes parallel to the disk surfaces were evaluated using particle image velocimetry (PIV) at a Reynolds number corresponding to a typical operating condition. We focus on the flow behavior near the arms and in the shroud opening, influenced by the insertion angles of the arms.

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Measurements of void fraction distribution around tubes across horizontal tube bundle in liquid-gas two-phase flow were carried out using X-ray radiography system. Under bubbly flow condition, it was observed that bubbles mainly passed through the vertical tube gaps and accumulated on the upstream side of the tubes. Also it was observed that void fraction was lower around the wall side tubes than that the center tubes. Measurements results of the void fraction were underestimated comparing to the previous studies. Because void fraction near the wall is lower than that in the center-region. Thus, cross-sectional averaged void fraction decreased comparing to the void fraction which was averaged except for the near-wall region.

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Influence of background rotation on the behavior of a bubble plume in a tank is investigated experimentally, purposing a flow control for large LNG container subject to the Earth rotation. We used the rotating tank facility in University of Warwick, and found a single air-chimney stabilized in the case of point-source of air injection. In contrast, the line-source bubble injection resists to the chimney formation and keeps planer curtain like structure. We also found eccentric oscillation of bubble plume in the disk-source type of injection.

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Wavy concentrations of mist flow are observed in a horizontal pipeline as Reynolds number falls into transition regime between laminar and turbulent states. We analyzed numerically the behavior of the mist using synthetic gas phase flow structure which models turbulent puffs, and succeeded in simulating the wavy passages.

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The purpose of this study is to discuss bubble-bubble interactions in a pair of zigzagging-ascend bubbles. For this specific purpose, a bubble generator that controlled the formation and launch of bubbles precisely was employed. The bubble's equivalent diameter was 2.68 mm. The two bubbles were launched and the initial bubble-bubble distance was 3.5, 4.0, 4.5, 5.0, 5.5 mm. The relative angle θ between the leading bubble and trailing bubble were set at 30°. Using a high speed video camera and PIV, we visualized motions of the bubbles and their surrounding liquid motion. The liquid motion induced by the trailing bubble was considered to enhance dynamic pressure acting on the leading bubble. The leading bubble took symmetrical-ellipsoidal shape, and symmetric property of the surrounding liquid motion has become stronger. As a result, a zigzag motion of the leading bubble was suppressed.

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The purpose of the present study is to enhance measurement accuracy of a Single-Tip Optical fiber Probe (S-TOP) in droplet measurement. The S-TOP only with a wedge-shaped tip enables simultaneous measurement of the diameters, velocities and number density of bubbles/droplets. To accurately measure droplets in a spray, discrimination of a touched position by the S-TOP is essential. In this study, we revealed a characteristic peak-noise (a post-signal) contained in an output signal of the S-TOP. The post-signal intensively appears when the S-TOP penetrates a droplet at its pole. We experimentally quantified the relationship between the intensity of the post-signal and the touched position. As a result, the touched positions could be easily and reasonably discriminated by the post-signal method. This new detection technique successfully improved the accuracy of the S-TOP droplet measurement; the difference in the measured results of the S-TOP and visualization becomes smaller than 5 % at most.

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A wireless electrical resistance detector has been developed in order to measure the real-time particle volume fraction in a centrifuge for controlling a rotational velocity and particle supply rate. The developed detector was attached around a cylindrical vessel to be mock a centrifuge. With the developed detector, the particle volume fractions in sodium chloride solution were measured under experimental conditions of various rotational velocities, particle supply rates and measurement cross section positions. The particle volume fractions are increased as the rotational velocities and the particle supply rates are increased, and the particle volume fraction is decreased as the measurement cross section position is increased. The measured particle volume fractions coincide with an anticipated tendency of particle volume fraction. The appropriateness of measurement results is qualitatively validated.

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The Cavitation reduces the performance of the fluid device. When the cavitation bubbles collapse, it will causes the shock wave and sometimes causes the micro-jet towards the wall. We visualized the laser-induced bubbles using BOS(Background Oriented Schlieren) method. The BOS technique is one of the visualization techniques, which enable us to perform experiments with simple optical system, and it requires a high-speed camera, a background image and a light source across to illuminate a background. The principle of BOS technique is similar to conventional Schlieren technique. As a result we have been able to visualize the density information of the shock wave induced by laser.

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Inside automobile engines, it is important to control the generation of liquid film and liquid film behavior. There have been some studies to classify steady wave or transition to breakup and scattering by cross-flow. However, clear visualization measurements of interaction between liquid film and cross-flow are also needed because transition and scattering are indefinite to be predicted. In our experiments, air from wind tunnel flows on the water film in a square duct, and the film is photographed using the high speed camera in various conditions of air and water velocities. It is found that the liquid film behavior can be definitely classified in four, that is smooth, wave, transition and scattering by dimensionless parameters. And the Kelvin-Helmholtz wave transition equation is applicable to transition region the beginning part of our work about the dimensionless numbers.

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Knowledge of turbulent flows in rod bundles is important for improving safety analysis codes for nuclear reactors. In this study, we therefore measured liquid velocity in single-phase and bubbly flows by installing a small LDV probe into a rod of a 2×2 rod bundle. The local time-averaged velocity and turbulent intensity were obtained from 10,000 instantaneous velocities at each measurement point. The Reynolds shear stress in the rod gap was evaluated from velocity data measured from two directions. The experimental results showed that (1) the turbulence is enhanced due to the presence of bubbles at a low liquid volume flux, whereas the turbulence modification due to bubbles is not clear at a high liquid volume flux, and (2) the Reynolds shear stress can be evaluated by measuring velocities from two different angles between the horizontal plane and the optical axis of the LDV not only for single-phase flow but also for bubbly flow.

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The direct numerical simulation (DNS) of the turbulent channel flows by the sudden changes of the Reynolds number (Re) is performed to investigate the transient phenomena in the turbulence field. In the first stage of the transient state, the wall friction changes to unit during a very short time. Then again that is recovered about 10% in the second stage and the profiles of the mean quantities asymptotically reach to the fully-developed ones. At the case of the sudden Re increase, the low-speed streaks are weakened, while at the inverse case those are enlarged temporarily in the transient state.

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In this study, the direct numerical simulation (DNS) of compressible turbulent flows through the square duct with several arrangement patterns of the adiabatic walls is performed and the flow fields are investigated. The friction of the adiabatic wall decreases and the flow near the adiabatic wall is stabilized. The drastic change of the secondary flow in comparison with the incompressible one occurs only in the case of one adiabatic wall. The arrangement patterns of the adiabatic walls have an influence on the distribution of mean quantities. From the results of instantaneous fields, the vortex structures are inactivated in the case of three adiabatic walls.

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In this study, the results were discussed of experimental investigation of supersonic jet. The jet becomes underexpanded when the pressure ratio exceeds the critical value across the convergent nozzle discharging it. The jet is not uniform because of the presence of the expansion wave, the compression wave and the shock wave formed in it. In this experiment, the flow field is experimentally visualized in order to analyse the behavior of jet.

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Experimental investigations on heat transfer caused by side-jet injection into hypersonic cross flow were performed. The present paper describes analysis of aerothermodynamic effects of several vortices which are generated in separation region in front of side-jet stream. Measurements of heat transfer distribution with high spatial resolution were conducted by using Temperature Sensitive Paint to reveal the influence of small vortex structure in the separation region. In addition, numerical simulation was performed simultaneously. As a result, surface heat transfer distribution caused by the aerodynamic interaction showed characteristic patterns of heating and they showed good agreement with the prediction by the numerical study.

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The present study reports of passive technique to enhance the cavity-induced pressure oscillations by modifying the cavity leading edge configuration. 3 (three) leading edge geometries namely circular-contoured, slanted and circular contour on 30° slant edge were used in the study. The density-based algorithm in ANSYS Fluent 13.0 was used to solve the time dependent Navier-Stokes equations. The SST k-ω model was used for modeling the turbulence within an unstructured mesh solver. Validation of the computational code used was accomplished and the results showed a good agreement between the numerical simulation and experimental data. The study comprised the analysis of pressure oscillations in and after the cavity. The modification of cavity leading edge shown influencing to the pressure fluctuations.

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This study describes pressure drop characteristics at a rectangular elbow that a sudden contraction or a sudden expansion simultaneously occurs. This flow pattern can be found in high-density packaging electronic equipment. In order to predict flow pattern of cooling air in electronic equipment, an accurate prediction of airflow rate cannot be achieved by using conventional formulas for calculating pressure drop characteristics in simple ducts. This paper especially clarified the pressure drop characteristics at the rectangular elbows with the sudden contraction or the sudden expansion through the experiments. A relationship between the pressure drop and a change of the cross section area of the flow passage between an upstream side and a downstream side of the elbow was investigated. By using our experimental results, a prediction formula of the pressure drop was developed.

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Behavior of an air flow around a permeable porous plate placed perpendicularly on a heated ground plane was experimentally investigated with the aid of a laser Doppler velocimetry. The experiment was performed for three kinds of porous metal plate with different porosity and permeability. From mean streamlines around porous plate, we found that a recirculation region moved to downstream with increasing in permeability and disappeared for the highest permeability. In addition, temperature measurements were also conducted to assess a local Nusselt number. The Nusselt number distributions along the streamwise direction showed that a heat transfer was enhanced just behind the porous plate because of the air flow permeation. At the highest permeability, abovementioned phenomenon was remarkably observed, but increasing in Nusselt number due to the effect of reattachment of flow did not occur.

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When a cylinder rotating around horizontal axis was put on the turntable rotating around vertical axis, and when a device to trim the powder attached to the cylinder wall was added, wheat flour and aluminum powder could be stirred well. But starch and aluminum powder could not be stirred well with that way. It was found that they could be stirred well, if the axis of the cylinder was set apart from the horizontal axis of rotation with distance of several mm.

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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. Its filtering effect about 2.1mm particles was explained well by the theory of branch pipes. In this report, filtering effects about 8.5 μm particles were studied. It was found that the filtering effects were better than the theoretical values, because the concentration of particle in the boundary layer on the rotating disk was less than that outside of boundary layer. Next, number of suction holes was increased from 8 to 12, and their filtering effects were studied. It was found that the filtering effects decreased with more than 9 holes.

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Trees pump up water to the high leaves with narrow tubes. It was found that we could also pump up water to high places with narrow tubes without large energy loss as follows. (1)Narrow tubes less than 2.5mm inside diameter were used to maintain a column of water by surface tension. (2)Water columns total length of which was less than 10m were pumped up by decompressing the upper part of narrow tube. (3)The speed of columns of water had to be maintained less than several mm per second, otherwise columns of water were divided into a lot of drops of water.(4)To achieve the purpose, an airtight container filled with water was used, from the bottom of which water was drained drop by drop, and the top of which the upper part of narrow tube was connected. (5) An orifice was set at the narrow tube exit to prevent increasing velocity of water column when it flew into a collection device. (6)When orifices were set in a narrow tube at the interval that is shorter than the length of one column of water, plural columns of water could be pumped up continuously, and plural narrow tubes could be used with one airtight container.

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When the strong wind blew at an umbrella parallel to the ground from the unexpected direction, the umbrella was lifted by the lift force, and the umbrella was inclined to the opposite direction of the wind by the drag force. The umbrella received a strong wind on the back side (concave), and the umbrella turned inside out, and the ribs were broken in this way. These were found settled as follows. When a hinge turning freely was arranged at the top of axis of umbrella and the angle was maintained with springs, the umbrella inclined to the direction of wind, and the umbrella received downward lift force. The umbrella could always receive the strong wind on the convex surface, and ribs would not be broken. Furthermore, it would reduce the rain person suffered.

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This paper presents two-dimensional ow around NACA0012 in a periodic flow with a sinusoidal velocity profile in the streamwise direction. The measurement is conducted in water tunnel under Reynolds number Re = 3000, reduced frequency k = 2.27 and angle of attack 15°. The phase-averaged velocity field is measured by using Particle Image Velocimetry (PIV). It is found that high phase turbulent intensity points are observed on the separation/reattachment points in one period.

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For various types of viral infectious diseases represented by influenza, it is an important issue to prevent a risk of viral infection. In addition virus can penetrate in respiratory, then viral adhesion part is difficult to revealing. In this paper, to specify where virus adhere in respiratory tract, viral movement were simulated by CFD using some parameters based on epidemiology. As the parameters, change in droplet radius because of evaporation, a sedimentation rate of particle was adopted. In addition, flows caused by breathing were also thought for the computation. As a result, visualization of viral movement was observed by the simulation. Then a possibility of contribution to specifying infection part was shown.

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Nasal continuous positive airway pressure (Nasal-CPAP) is frequently used in the care for the preterm neonates.In previous report,We had developed a nasal CPAP device with bypath (BNCPAP) of vertical allocated type with additionally compiled HFOV function. In the present report, we have optimized the positions terms of Two relation with Two holes. As the result, CPAP pressure increases about 40Pa during respiration phase.

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The Great East Japan Earthquake in 2011 caused a giant tsunami which led serious damage in the Tohoku and Kanto areas. According to studies after the earthquake, breakwaters mounded the bottom of the bay were destroyed by the tsunami and their disaster mitigation effect did not work. For tolerant breakwater of tsunami struck, we investigate effect of submarine plates which are set close to breakwaters. In the present study, we conduct numerical simulations of the flow around breakwaters with the submarine plate. The MARS method is employed to capture the free surface of tsunami and the k-ε model is used as turbulence model. Results show that the submarine plate decreases wave forces of tsunami and a breakwater's tolerance of tsunami is improved.

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The influence of revetment on wind current at closed shallow water regions was examined by water tank experiment using PIV. The wind current changes its direction in the region close the revetment and becomes the countercurrent near the bottom of the water tank. Velocity and velocity fluctuation of countercurrent are large at the revetment side. They are smaller at the offing side. They vary with angle of the revetment. The revetment with gentler angle realizes higher velocity and fluctuation at offing side. These results suggest sediments on the bed near gentle slope are easily transported in closed shallow water regions.

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Although the integration of computation and experiment in fluid dynamics has been steadily progressing, and the recent development of measurement techniques of flow velocity enables us to obtain highly accurate data for various flow fields, several difficulties occur in a real environment. One of most difficult issues is how experimental data can be easily obtained in a wide region. In this study, we propose a portable flow visualization device system, which focuses on the cost-effectiveness and easy handling. In this paper, two measurement techniques of three-dimensional flow velocity are introduced. One is a measurement method of three-dimensional flow direction using tufts, which the locations of the endpoints of the tuft are automatically measured by two or more versatile USB-cam and recent image processing libraries. The other is a new method of generating a slit light using rotating multiple light sources. It is shown that, in a real environment, the three-dimensional coordinates of two endpoints of the tufts are obtained by the proposed method, and the flow field around a bluff body is visualized using a slit light which generated by the rotating multiple light sources.

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The micromixer, which has a rotor with a curved channel, is studied experimentally. The Taylor-Dean flow in a curved channel of rectangular cross-section is investigated using PIV (Particle Image Velocimetry) and LIF (Laser Induced Fluorescence) methods. Two walls of the channel (the inner and top walls) rotate around the center of curvature and a pressure gradient is imposed in the direction of the exit of the channel. The non-dimensional parameters concerned are the Dean number De and the Taylor number Tr. Photographs of the flow in a cross-section at 180° downstream from the curved channel entrance are taken by changing the flux (De) at a constant rotational speed (Tr) of the channel walls. It is found that good mixing performance is obtained in the case of De ≤ 0.1Tr. This tendency appears more strongly if aspect ratio is large. And we have confirmed the effect of secondary flow on the mixing.

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Chaotic mixing in a curved-rectangular channel flow is studied numerically. One wall of the channel (inner wall) rotate around the center of curvature and a pressure gradient is imposed in the direction toward the exit of the channel. This flow is a kind of Taylor-Dean flow. There are two parameters dominating the flow, the Dean number De (∝ the pressure gradient) and the Taylor number Tr (∝ the angular velocity of the wall rotation). In the present paper, we analyze the physical mechanism of chaotic mixing in the Taylor-Dean flow by comparing fluid mixing and velocity field. It is found that good mixing performance is obtained in the case of De/Tr ≤ 1/6. This tendency appears more strongly if aspect ratio is large.

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Particle focusing into a specific area in a microchannel is especially important for precise particle detection, separation and sorting in various microfluidic devices for biomedical diagnostics and cell biology. In recent years, although various particle focusing approaches in microchip have been reported, they have some problems such as complicated fabrication and peripherals. This study suggests an innovative three-dimensional (3D) hydrodynamic particle focusing technique applicable in wide Re with only two inlets. The performances of the particle focusing m under different flow rates and channel shapes were evaluated by numerical simulation. In addition, experimental evaluation of the focusing was performed by particle speed measurement. As a result, we confirmed the validity of the proposed particle focusing technique.

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Metal nanoparticles have unique electrochemical and optical properties depending on their conditions, such as size, shape or aggregation, and are extensively expected as an advanced sensor in various fields. We have developed a microfluidic device capable of generating a stable concentration gradient in microchannel as a reaction field for nanoparticles. In this device, nanoparticle solution is seeded in the concentration gradient. The aggregation of gold nanoparticles (15 nm in diameter) in NaCl aqueous solution was employed as a sample. It was confirmed that a continuous change in the color of solution reflecting the degree of aggregation in accordance with NaCl concentration.

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人工心臓の歴史的背景、拍動型から回転型までの人工心臓ポンプの種類、耐久性を決める軸受の種類、人工心臓開発で重要である血液適合性向上への流体工学的視点について解説した。

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