Non-equilibrium behavior of the turbulent pipe flow subjected by sudden change of the wall roughness has been investigated experimentally. The mean velocity, streamwise turbulent intensity and the local wall shear stress were measured for the initial stage of the process after sudden change wall condition from rough to smooth. The mean velocity show acceleration before approaching to fully-developed smooth wall flow. The local wall shear stress shows the overshoot behavior over the relaxation process. Gradient of the logarithmic velocity approach to fully-developed smooth wall flow in the early stages.

Most wall-bounded shear flows undergo a subcritical transition scenario. The lowest limit of the transitional regime features intermittent coherent structures that are, for instance, turbulent-laminar patterns in plane channel flows. The transitional phenomena on smooth walls have been considered well; however, walls in industrial situations have hydro-dynamically roughened surface, since a perfectly smooth wall is ideal and uneconomic for production. The aim of this study is to elucidate the influence of roughness on the turbulent-laminar patterns and to evaluate the robustness of the turbulent-laminar patterns on the roughness wall. We study plane Couette flows with one/two rough wall(s) by means of direct numerical simulation and found several flow structures in roughness induced regime.

Wall shear stress fluctuations are difficult to measure in the experiment, because it is hard to measure directly the velocity gradient close to a surface since the boundary layer thickness is so small that any measuring instrument will disturb the flow. However, a diffusion-controlled electrochemical reaction at small cathodes embedded in the wall can be applied to obtain the velocity gradient at the wall. In this paper, shear stress fluctuation measured by electrochemical method of turbulent pipe flow are analyzed and compared with LES through the power spectrum and probability density function. As well as use one low-pass filter to pick up the low frequency part for checking the effect of large-scale motion to the shear stress fluctuation, and the large-scale structures movement.

Change of the flow structure in the turbulent magnetic fluid flow by applying magnetic field was investigated experimentally. Measurements of the velocity distribution and Reynolds shear stress distribution were performed by Ultrasonic Velocity Profiling (UVP) method. The flow velocity of the magnetic fluid flow increases at the duct center but decreases in the near wall region by applying magnetic field. Moreover, the Reynolds shear stress is suppressed by applying magnetic field. This suppressed Reynolds shear stress becomes large in excess of that without magnetic field in the downstream of magnetic field region, and then it recovers to the first state.

In order to investigate turbulence structures and to clarify the sustaining mechanism of aeroacoustic sound sources in wall turbulence in the future, a turbulent boundary layer of compressible flow was simulated by using the direct numerical simulation technique. After that, the characteristics of large scale and fine scale pressure structures were observed by applying a spatial filter to the structures of pressure distribution. The simulation results showed that the large scale structures are correlated with pressure fluctuation on the wall surface. In addition, the frequency of the growing large scale structures corresponded to the frequency of the propagating pressure wave. The analysis results suggested that the large scale structures could be associated with sound sources.

Turbulent flow at high Reynolds number introduces large scale structures in the outer region which affect the turbulent motions. Reynolds number dependence on the pressure fluctuations is studied from Direct Numerical Simulations (DNS) data set at Reynolds number 180, 400, and 1000. The results indicate that the peak of root mean square value (r.m.s) of total, slow, and rapid pressure fluctuations depend on the logarithmic Reynolds number. Probability density function (PDF) for the total pressure shows slice difference between the studied range of Reynolds number. Power spectra are similar for the three pressures close to the wall, and at the center of the channel, rapid pressure shows different behavior in the intermediate and the high wavenumber range. Scale structures associated with total, slow, and rapid pressures introduce variation with the Reynolds number suggesting for more work in the scaling analysis.

The local wall shear stress measurement technique has been developed using a thin plate called as “sublayer plate” attached to the wall in the sublayer of the wall turbulent flows. Pressure difference between forward and backward edges of the plate is correlated to known wall shear stress obtained in the fully developed turbulent channel flow. The calibration curve can be well represented in dimensionless group and the new method has sensitivity as high as that of the sublayer fence, even if it is submerged in the linear sublayer. The additional experiments prove that the sublayer plate has reasonable angular resolution to detect the local wall shear stress direction.

Flow Visualization technique was applied to measurement of the local wall shear stress with the aid of thermo-liquid-crystal. Two alignments of thermos-liquid-crystal, nichrome thin film and headed wall with micro-protrusion, were tested in a fully developed channel flow and calibration curves were obtained by given local skin friction coefficient. The wall temperature detected by color analysis of thermos-liquid-crystal at particular part on the wall can be correlated by 1/3 power of the local wall shear stress. Nichrome thin film type has wider rage for the wall shear stress measurement. Otherwise, heated wall with micro-proportion type is higher in sensitivity.

Behavior of magnetic fine particles in a MR fluid in the presence of magnetic field was investigated using the hybrid method of .HSMAC method and discrete particle method. Simple shear flows of MR fluid between two parallel plates were calculated when magnetic field perpendicular to the flow direction was applied. Many chain-like clusters are formed in the field direction and clusters are broken and reconnected around the central area in the relatively strong shear flows.

In the present study, a miniaturized magnetically-driven heat transport device using a binary temperature-sensitive magnetic fluid is newly designed, and its driving characteristics are investigated to develop it for the application for CPU cooling. The experimental results show that the measured flow rate periodically oscillate with the time elapsing. The reason is revealed from the numerical results that a gas bubble moves from high to low pressure region due to the effect of the magnetic buoyancy. Consequently, it is found that the bubbles trapped in the low pressure region lead the periodically oscillating flow rate.

In order to develop of MR fluid of extremely low no-field viscosity and higher operating temperature, we have fabricated novel "dry MR fluids", and have measured and evaluated the fluidity and MR properties. The dry MR fluid is a novel MR fluidic powder, which is mainly composed of micron-sized carbonyl iron particles coated with nano-sized particles without liquid medium. In this study, the formation and breaking behavior of the particle cluster or column in shear flow mode of the dry MR fluids have been visualized using the developed magnetic field applicable MR fluid shear flow device consisting of circular gap between rotational and fixed disks, and the behavior has been investigated in close relation to the measured fluidity and MR properties of the dry MR fluids. The developed MR fluid shear flow device successfully performed the visualization of the formation and breaking behavior of the particle clusters and columns in the shear flow mode of the dry MR fluids.

In this study, an evaluation equipment was developed to estimate durability of MR fluids quantitatively. The developed machine can perform the durability test for MR fluids without influences of sealing materials. The durability for two types of the MR fluid was estimated, in cases with /without a sealing oil in order to reduce the effect of the atmosphere. The experimental results show the durability of MR fluids was affected with the stability of the solvent.

Recently, engineering applications of ion transport phenomena and related liquid flows have attracted much attention. Since fabrication techniques of micro- and nano-fluidic channels have enabled us to precisely control such flow fields, several technologies, such as micro-pumps, rectifier, and ionic field effect transistors, have been developed. On the other hand, some ambiguities have remained in the mechanism of liquid flows driven by interacting ions. In this study, liquid flows driven by ion transport phenomena are investigated to deepen the understanding of fundamentals and to extend this kind of flows to be available in the larger space. Herein, liquid flows dragged by electrophoretic transport of ions are experimentally observed in a flow channel that has a 1 mm × 1 mm cross-section. We succeeded to induce electrohydroynamic flows in millimeter-scale spaces and furthermore, the applied electric potential was extremely reduced by preparing monopole ion solutions in which positive or negative ions were dominantly presence.

Quincke rotation is the rotation of non-conducting objects immersed in dielectric liquid and subjected to a strong homogenous DC electric field. The rotation is spontaneous when the field exceeds a threshold value. In this research, for the purpose of developing a micro motor utilizing the Quincke rotation, polymer composites have been developed as materials for a micro motor rotor, and the motor characteristics of a miniaturized cubic micro motor of 3 mm square and 7 mm in height with cylindrical electro-active-polymer(EAP) composite rotors of 1.0-1.5 mm in diameter and 0.5-2.5 mm in length, are investigated as a function of electric field intensity and the diameter and length of the cylindrical rotors using a high speed video camera. It is found that the rotational speed of the motor without load increases with increasing electric intensity and decreasing both diameter and length of the rotor, and the induced torque of the motor decreases with increasing the rotational speed and increases with increasing the electric intensity and decreasing both diameter and length of the rotor. And also, we have succeeded in controlling the rotational direction using two added electrodes both sides of GND electrode in order to break the symmetry of the electric field.

Cellulose micro fibrils extracted from woods have considerable potential to be applied to innovative composite materials due to their properties such as low density and high strength. In order to utilize these outstanding properties effectively, the fibril alignment must be controlled to be parallel. In this study, an innovative method for controlling cellulose micro fibril alignment by AC electric field has been proposed. Characteristics of fibril alignment under electric field have been analyzed through visualization and qualitative evaluation by optical measurement. Under AC electric field, fibrils align parallel to the direction of the electric field by torque acting on electric dipole of fibrils and then agglomerate in the vicinity of the electrodes through induced flow by dielectrophoresis. Furthermore, the degree of fibril alignment increases almost linearly with applied voltage. Higher degree of fibril alignment is shown for higher applied voltage at lower frequency.

Thermal and fluid dynamic behavior of cryogenic micro-solid nitrogen particles produced by a superadiabatic laval nozzle using single-component transonic nitrogen flow was developed and numerically investigated in application to nano-order semiconductor device cleaning. To investigate the characteristics of nano-order semiconductor device cleaning, elucidating the atomization process in laval nozzle is neccesary. Governing equation based on LES-VOF model is applied to clarify the sequential process of liquid atomization of primary break up to secondary breakup of cryogenic fluid in laval nozzle, and integration with experimental study was conducted to verify the availability of cryogenic cleaning technology.

Natural circulation of supercritical and liquid two-phase CO₂ was investigated. The experimental solar water heater is installed at 30 ° and 90 ° of tilt angle. In the present study basic characteristic of energy transfer are focused on thermo-fluid behavior due to gravity force in two conditions of collector tilt angle (30 ° and 90 °). From the experimental results, it is found that the mass flow rate of CO₂ is increased, when the collector tilt angle is at 30 °, because of a large difference in density and the collector head. In addition heat transfer characteristics were increased with the increase of the Reynolds number and the Prandtl number.

Photovoltaic-thermal hybrid solar system consists of photovoltaic solar module and solar thermal collector. The hybrid system can generate electric and thermal energy simultaneously, and when also can recover the efficiency of electric power output to decrease the temperature of photovoltaic panel. In this study, for the purpose of improvement of heat efficiency in photovoltaic-thermal hybrid solar system, thermal dynamics characteristics of two phase flow (water + n-Hexane) was investigated. It was found that temperature at outlet of experimental apparatus is increasing with increasing mass flow rate. In addition, heat transfer was enhanced by changing from laminar flow to turbulent flow and emulsification of working fluid in high mass flow area.

We predicted the trailing edge noise operating in the maximum efficiency point of a propeller fan by the measured wake characteristics. The relative flow in the design point separated at the pressure surface. In this case, it was deduced that the flow around the impeller may not interact with the neighbor blade. The blade load was distributed on the blade span; the velocity fluctuations of the same operation point became large than that of the off-design point. The results of the predicted noise indicated that the influence of the relative velocity on the trailing edge noise was larger than that of its velocity fluctuation.

In order to apply the hot-film sensor for the analysis of the aerodynamic sound source, we measured the noise signal on the automobile door mirror. CAA (Computational Aeroacoustics) was applied for the estimation for the magnitude of the quantitative noise source. We clarified that the one of the features of the aerodynamic noise generated from the actual automobile mirror in the wind tunnel test were low frequency noise. The low frequency noise was occurred by the perturbation of the long wave length formed at the tip of the mirror. The fluctuation signal of the hot-film sensor became large at the tip of the mirror. The results of measured signal indicated the same tendency in the CAA analysis.

Flow around the front-pillar of an automobile is typical of a flow field with separated and reattached flow by a longitudinal vortex. The longitudinal vortex generated behind the front-pillar of a vehicle is reproduced by the three-dimensional delta wing. The wing with attack angle of 15 degrees was merged in the uniform flow speed of 10 m/s. Computational Fluid dynamics (CFD) analyzed time-derivative of surface-pressure-fluctuations and the aerodynamic sound in the far field As a result, it was found that time-derivatives of surface-pressure-fluctuations have correlation with the aerodynamic sound in the far field. This method is considered an effective way to detect the sound sources on the solid body.

The paper describes the generation mechanism of aerodynamic sound produced by the delta wing with attack angles 15 degrees to the uniform flows at a speed of 10 m/s. Flows around the front pillar of an automobile are known as a typical flow field with longitudinal vortex system. The delta wing reproduced well the vortex system. The objective of the present study is therefore to clarify the relationship between vortical structures and aerodynamic sound by using the delta wing. Computational Fluid Dynamics (CFD) analyzed the flow field and aerodynamic sound with unsteady acoustical method. CFD captured clearly unsteady motions of vortices. First large-scale vortices are generated at the tip of the wing and after that along the vortical axis the vortices are broke down to small–scale ones due to the effects of the viscosity and convection of the rotational flows. As a result, it was found that vortices are generated, transported, and diffused in the longitudinal vortex system through energy cascading process.

Numerical analysis was performed to simulate the flow field and predict the aerodynamic noise in an open type small scale wind tunnel. The numerical scheme was based on Lattice Boltzmann Method (LBM) and the direct method was introduced to predict the aerodynamic noise. Large Eddy Simulation (LES) with the wall function was used for the turbulence modeling. As a result, the velocity distribution on the cross-section of the main jet obtained by numerical analysis was in good agreement with the experimental result. The vortex ring of the discharge nozzle shape was reproduced. The generated vortex ring splits into the small one while going downstream. The spectrum of aerodynamic noise was also predicted. Comparison of the numerical and experimental results shows that the numerical analysis is an effective design tool for the development of low-noise wind tunnel and can be applied to the development of various low-noise products.

In this study, aerodynamic sound generated some tapered cylinders and a circular cylinder under the condition of inflow turbulence are measured. Reynolds number based on tapered cylinder diameter at the mid span and inflow velocity is 2.7 × 10⁴ . The inflow turbulence is generated by using the turbulence grids and it changes to turbulence intensity of 12.6% and 19.1%. The results show that the Aeolian tone reduction is larger for high taper ratio model than circular cylinder but it is small with inflow turbulence. Under the turbulence intensity of 19.1%, the Aeolian tone cannot clearly be observed for both the circular cylinder and the tapered cylinder, and aerodynamic sound increases on broad band in sound spectra.

In this paper, surface pressure and NACA0012 airfoil flows are measured by wind tunnel test with inflow turbulence using the active turbulence generator (ATG) in order to clarify unsteady airfoil flows behavior contributed to airfoil noise under atmospheric turbulence. Turbulence intensity of the inflow can be changed from 10 % to 20 % and integral scale of the inflow set to 300 mm of 2 times chord length. The Reynolds number based on the chord length of the airfoil and flow velocity is 3.0×10⁵. As the results, short bubble generated on the suction surface seems to be disappeared by the inflow turbulence. Also, velocity profiles and spectra of surface pressure fluctuation and velocity fluctuation on the turbulent boundary layer on the suction surface cannot be seen effect by the inflow turbulence.

To clarify the mechanism of the control of cavity tone by plasma actuators of which electrodes are aligned with the oncoming flow, direct aeroacoustic simulations were performed along with wind tunnel experiments. The effects of the pitch of the actuators are focused on. The measured results show the most intense reduction of cavity tone is attained at the ratio of pitch to boundary layer thickness, p/δ = 10.9. The predicted results elucidate longitudinal vortices in the controlled cavity flow, which are originally generated by the actuators. By these longitudinal vortices, the large-scale vortices with the spanwise axis related with cavity tone are weakened and have spanwisely non-uniform structures.

Recently, it has been a problem of aerodynamic noise radiated from airfoils. Therefore, the authors made wind tunnel tests to measure airfoil noise and static pressure on an airfoil (NACA0012 model, chord length: 150 mm, span length: 500 mm, wind velocity: 30 m/s, angle of attack: 9 degrees, Reynolds number: 3.0×10⁵ ) in turbulent flow. In this study, the authors use the airfoil and a cylinder to examine influences of vortices with a particular size and fluctuation. Then, the authors measure airfoil noise and static pressure in varying position in the vertical direction (-60 to +40 mm) and diameter (6 to 10 mm) of the cylinder placed in the upstream side of the airfoil to change interference position and size of the vortices and airfoil. As a result, it has become clear that airfoil nose is increased when interference position is in the stagnation point. And the airfoil has larger pressure fluctuation at leading edge in this case.

The properties of Pressure-Sensitive Paint (PSP) with an ionic liquid as a binder have been investigated. An ionic liquid is a salt in the liquid state at room temperatures. The aggregation of pressure-sensitive dye often occurs in the polymer binder of PSP and gives an influence on the PSP properties such as pressure sensitivity and luminescence intensity. It is expected the ionic liquid as a binder avoids the aggregation of the dye and enhance the PSP properties. In this study, we developed the PSP with the ionic liquid and pressure and temperature sensitivities were measured in a calibration chamber. The developed PSP showed a high pressure sensitivity of 0.9%/kPa and a high temperature sensitivity of 2%/°C.

The supersonic mixing field induced by a novel wall-mounted cavity having a three-dimensional shape is investigated experimentally and computationally. In the experiments, the phase-averaged pressure oscillation fields are measured by using anodized aluminum pressure-sensitive paint (AA-PSP). The experimental results are compared with the computational results obtained by solving the Navier-Stokes equations. It is found from the experimental and computational results that pressure waves propagate in the cavity and that the waves act on the jet so as that it fluctuates largely. Such large fluctuation of jet is one of the primary reasons why mixing is enhanced by using the proposed cavity.

This research aims to register luminescence images obtained in a pressure-sensitive paint (PSP) measurement by using PSP and temperature-sensitive paint (TSP) dots in the dual-array sensor as markers. This reduces measurement error caused by position difference between obtained images in a PSP measurement without any additional markers. In this research, pressure and temperature distributions caused by a jet impingement was measured the dual-array sensor. We detected geometric centers of each PSP and TSP dot, interpolated the dot images, and registered the interpolated PSP and TSP images by the projective transformation. Obtained pressure distribution by this method qualitatively well agreed with the distribution which was interpolated after calculating each pressure value at each dot position.

Pressure-sensitive paint (PSP) is an optical and non-intrusive pressure measurement technique, and is used in wind tunnel testing. In general, PSP is applied to a model surface by a sprayer by hand, resulting in non-uniform layer. Recently, we proposed a novel PSP paint technique using an inkjet printer. This technique enable us to easily paint uniform PSP. In this study, we fabricated a combined PSP and TSP (temperature-sensitive paint) by inkjet printer. PSP and TSP were symmetrically painted on a substrate. Then, we measured the pressure and temperature distribution induced by impingement jet. The obtained pressure distribution was in good agreement with the literature.

An aim of this study is to combine a two color phosphor thermometry with the Particle Image Velocimetry (PIV) for a measurement of gaseous flow at high temperature. A temperature distribution of heated wall was preliminarily measured using the developed two color technique, which estimated temperature from a ratio of luminescent intensities in different ranges of wavelength, 500 ~ 600 nm and 400 ~ 480 nm. Differences from measured temperatures by thermocouples were 7.8 ± 0.8 °C in maximum. A velocity distribution of an impinging jet was also preliminarily measured by the PIV with phosphor particles.

The objective of this study is to develop a method to measure the concentration of mud. As the method, the LIF proposed by Kurioka was applied. In this LIF method, Excitation light attenuation isn't predicted by Beer-Lambert's law. In this experiment, the luminosity of the excitation light was obtained by measuring the luminosity of the scattered light by Nylon particles or Kaolinite particles placed in a water tank. It was found that the higher the concentration was between 0[g/l] and 0.3[g/l], the darker the luminosity of the fluorescence was. This relationship was applied in order to measure the concentration. The results showed in which measurement point the concentration was high or low.

Pressure sensitive paint (PSP) is very powerful method to measure pressure on solid surfaces. However, PSP has not only pressure dependence but also temperature dependence. In addition, error caused by temperature dependence have a great effect on PSP sensitivity in low gauge pressure condition. Therefore, it requires temperature compensation for precise pressure measurement in low gauge pressure condition. In this study we show the characteristics of dual-layer PSP/TSP with lifetime based method using high speed camera. Firstly, we checked mono-layer PSP and TSP characteristics with lifetime based method and optimum measuring point. Then we show the feasibility of the temperature compensation of PSP for dual-layer PSP/TSP for the measurement in low-speed flow fields with temperature distribution.

We have developed the method to apply fast-response pressure sensitive paint (PSP) to measurement of internal flows to analyze anomalous flow phenomena of internal flows of turbomachinery, and we have applied the method to measurement of pressure distribution of a casing wall surface of an axial compressor, to investigate the validity and feasibility of this method. We have clarified that the luminescence intensity is enhanced by applying the white opaque, oxygen-permeable coating composed of boron nitride (BN) nanoparticle on the PSP layer, and the qualitative pressure distribution showing pressure rises caused by rotor blades was obtained. Because uncompensated temperature influence is one of the other error sources, proper temperature compensation of PSP is needed to improve the accuracy of the pressure measurement.

Recently, by utilizing the non-equilibrium condensation phenomenon in the supersonic swirl flow, technology for the separation and extraction of condensable gases has been developed. However, there are many unresolved problems for performance of operating principle. In the present study, the effect of branch pipe on the non-equilibrium condensing flow with a swirl in a supersonic annular nozzle were investigated on the basis of the simulated results. As a result, swirling flow or expansion rate of branch pipe has strong effect upon condensate mass fraction at the nozzle exit.

Non-linear growing process of surface pressure fluctuation in the hypersonic boundary layer was studied. A 1100mm-length 7-degree half angle cone was applied for the series of experiments conducted in the high-enthalpy shock tunnel JAXA-HIEST. On the surface of the cone, sixteen high-speed pressure transducers-PCB132A were flush mounted from x=412mm (CH1) to x=1012mm (CH16) each 40mm apart (x shows the distance from the nose). Surface pressure fluctuations in the boundary layer on the cone was measured under the high-enthalpy condition (H₀=3MJ/kg), in which Reynolds number was 2.4x10⁶. The typical surface pressure histories depicted low-frequency (around 10kHz) Tollmien-Schlichting wave and extremely high-frequency (around 450kHz) 2^nd mode waves. To determine the resonant interaction of the 2^nd mode wave and other low frequency waves, cross-bispectrum analysis was applied. The analysis showed that a significant bispectrum coefficient was found at around 10kHz and around 450kHz, which result meant that there was a notable phase coupling between 2^nd mode wave and a low frequency wave, which frequency was identified to the Tollmien-Schlichting wave.

In this study, the behavior and structure of underexpanded jet were discussed. 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. Moreover, when a flat plate is placed perpendicularly to the jet, the strong wave called ‘plate shock' appears in the flow field near the plate. In this experiment, the flow field is experimentally visualized in order to analyse the behavior of jet.

Supersonic impinging jet on at flat plate is commonly used as a simple model of flow field of industrial applications of high speed jet such as an assist gas for laser cutting, a cooling jet in glass tempering process and so on. In case of axisymmetric jet, the air flows radially along the plate after the impingement and forms an underexpanded jet under certain conditions. In this study, such radial underexpanded jet is issued from a slit nozzle, which consists of two circular tubes facing to face each other. Jets at different pressure ratios across the nozzle are experimentally visualized using Schlieren method. Screech sound radiated from the jet is measured using microphone. Position of the sound source is considered to be near the end of second cell or in the region downstream of the second cell.

Laval nozzle is commonly used in the cold spray processing, which is a material deposition process using supersonic gas flow. Small powder particles of material are injected into the gas flow and accelerated to velocities enough to form film on a target surface. The velocity of gas flow inside and downstream of nozzle is one of the important factors to determine the collision speed of particles onto the target. In this study, the jet issuing from two dimensional laval nozzle and impinging on a flat plate is numerically simulated. By mounting a cover to the nozzle exit, the jet boundary attaches to the cover wall, the base pressure decreases, and the jet is further accelerated downstream of nozzle because of higher pressure ratio. Flow fields with different cover widths and lengths are compared with each other and the effects of such parameters on the collision speeds of particles are discussed.

Open water characteristics are measured in a circulating water channel with four model pectoral fins with different bending stiffness of Coelacanth. Open efficiencies reach highest value in the range of Strouhal numbers between 0.2 and 0.4 and maximum value of open efficiency increases with reducing bending stiffenss.

In late years a function and the structure of the creature called biomimetics are applied to technical development. We focused on the tuna that could swim in the water at high speed. A saw-like fin is between the tail and fins from the 2nd dorsal fin in fish like tuna. A fin of the triangle is called finlets, and there is in the back and ventral. It is thought that the finlets brings the effect that the flow behind the fish rectifies at present. Its role was inspected experimentally by the fluid force sensing using a made model. The experimental result by the fluid force measurement was not seen in the variation of the flow with or without finlets. The one when equipping finlets more than the time of non-equipment, indicated a higher C_D.

This study is that I make the robot which imitation of a leading vortex and evaluated the influence on flight in the phase difference of four pieces of feathers with wind tunnel test and animation analysis.

Intermittent Flight is used in small birds. In the present study, the flight path of intermittent flight was calculated and analyzed by wavelength, frequency and amplitude. The results, it was found that the frequency is smallest variation. It can be assumed that the intermittent flight at a constant frequency at the same species. In contrast, the amplitude is most variation. We will do the observation using a stereo camera, and improve of the model.

Avian respiratory systems consist of the cyclic structure involving some organs called by air sac. The birds ventilating with air sacs has uni-directional flow in the gas exchange bronchus. Here, it is thought that aerodynamic valve creating uni-directional flows because the mechanical valve not exist in the lungs. It is confirmed that similar flow exist in the lungs of reptiles, but there are still many questions about the generating factor about the uni-directional flow. In this report, we have inspected the influence that air sacs give the uni-directional flow by analyzing the avian respiratory system using the lumped parameter model. Based on the analysis result, we consider a process of the avian lungs evolution.

The machine perfusion (MP) techniques have extensively studied to preserve and resuscitate donated organ for organ transplantation. The MP technique is able to not only supply the organ with nutrition and oxygen continually through the preservation solution but also evaluate the liver viability. However, the perfusion machine that can evaluate liver viability is not yet established. In this study, the evaluation index was suggested by correlation between oxygen consumption dynamics and the liver function using porcine donated livers. As a result, the liver, which have oxygen consumption gradient of the low level was higher hepatic artery pressure and aspartate amino transferase of effluent enzyme. Therefore, oxygen dynamics of the liver during machine perfusion associated with the liver function and can used for the organ evaluation index before implantation.

Leaf venation has functioning of a transport channel of the water and nutrients in the leaves. It is possible to classify the leaves by those shapes. Differences of the flow pattern were observed with the different forms of leaf venation. In the net type venation, the water absorbed from the thick leaf vein to fine leaf vein. The water in leaf spreads to entire of the leaf with the branching of vein. The parallel venation and the dichotomous venation show that the vein branched from the root of leaf vein. The parallel venation has fine lateral veins to realize the bypass of flow. In the dichotomous venation, this does not have the connection of the other vein, however, this has the tiny hole in leaf vein. This suggests that water supplying realizes with the water exchange with the cell.

This paper describes the analysis of platelet aggregation on orifice flow by dissipative particle dynamics (DPD). DPD is a computational method for simulating platelet aggregation. In this paper, the DPD method is used for predicting platelet aggregation on orifice flow with concentration transport, and the sensitivities of the configuration and parameters on model are discussed. From computational results, it is found that effects of orifice configuration and parameter of interaction force on platelet aggregation are large compared with other factors. It is expected that the DPD will be combined with transport equation of concentration for accurate prediction of thrombus formation with aggregation.

Neutrophil is known as one of the immunological system, and it has chemotaxis by concentration gradient of cytokine. In general, the neutrophil is moved to high concentration of cytokine in the blood vessel, and derived to the inflammation areas. However, the mechanism of propulsion has not been elucidated yet. By understanding this mechanism, it can be applied to medical technologies such as drug delivery systems and micro machines. Therefore, it is necessary to elucidate the principle of neutrophil's propulsion. In our previous investigation, it was found that concentration gradient on the surface of neutrophil is reverse toward surrounding fluid. In this paper, detailed concentration distribution and concentration gradient on the neutrophil's membrane are examined by experimental. From the result, it was found that velocity of neutrophil's motion was changed by concentration gradient on the membrane.

The objective of this study is to understand the relation between flow and surface pattern. In the first step to obtain the objective, we visualize the flow around the cylinder array. Two types of array patterns are considered. One is the grid pattern. The other is the checked pattern. We make a comparison between previous studies and ours. The results by grid pattern show that the flow goes to between the cylinders. On the other hand, the checked pattern shows that the flow becomes three-dimensionally. The relation of the interval for the vortex formation behind the cylinder and the pattern of array to understand the flow structure are compared with the previous results.