Carbon/carbon composites plate is brazed to Ni-base super alloy, Inconel 600 using Fe-Cr base brazing filler. The Fe-Cr base brazing filler slurry was pasted on the C/C composites surface. The brazed surface of C/C composites was the cross section of laminates to make the residual thermal stress induced by the mismatch in the coefficient of thermal expansion. The brazing temperature was 1,050°C and the keeping time was 300s. The cooled specimen had crack just below the brazing interface inside of C/C composites. But the observation of microstructure revealed the sound bonding between the brazing filler layer and C/C composites. The Ni-base super alloy seemed to experience the dissolve and solidification process during the brazing. The diffusion of P in the Fe-Cr base alloy took the major role in formation of the microstructure.

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Erosion and Corrosion damage of stainless steel is caused by a molten lead-free solder in reflow and flow soldering bath. This phenomenon influences the operation periods and replacing timing of the components. Viscosity measurements of the molten Sn-Bi solder in carbon cell had been carried out to detect the change of rotation torque of stainless steel 304 cone plate with dissolving into the solder. The operation temperature was 160 degree Celsius, and shear speed was 105.6 rpm. An increase of rotation torque was observed about 200 min after from dipping of the cone plate into molten solder. After the viscosity test, a scanning electron microscope equipped with EDX observation of the surface of stainless steel cone plate contacted with the solder had been carried out. In the observed area of the plate, Sn and Bi elements could not be found out. Thus, this phenomenon was caused by elution of Fe elements of stainless steel into Sn, and it was identified with the increase of the liquids line of the tested solder. In addition, we tried to discuss about interface energy of cluster model calculated by Fermi energy because of the view viscosity is related to of their value of interface energy.

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Recently, from the viewpoint that decreases the load to the global environment, the bio-plastics, which are derived from the reusable resources from the biomass, attract much attention as new polymeric materials instead of the polymers derived from exhaustible resources such as petroleum. Poly lactic acid (PLA) is considered to be one of the most promising bio-plastics because its strength and modulus are as high as that of the existing plastic, and it has also biodegradability. In this study, we investigated the effect of immersion in gasoline on mechanical properties of injection-molded PLA plates in the case of assuming that PLA will be applied to severe environment such as in contact with gasoline.

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Vibrating reed (VR) technique can measure the Young's modulus which is dependent on the resonant frequency by making a thin board vibrate like a reed. In the previous report, it was shown that VR technique was effective as the way of measuring the degree of the absorption to the metal of hydrogen. Hence, the differences in the resonance frequency were found in some temperature range as a result of measuring the resonance frequency of the metal which absorbed hydrogen in hydrogen atmosphere, and that of the metal which didn't. In this report, after hydrogen was charged into sample SUS304 with the atmospheric pressure or 100MPa, changes in the resonance frequency were investigated in the diffusion process and in the separation process of hydrogen.

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In this study, the effect of ambient pressure and substrate temperature on flattening behavior of thermal sprayed particles was investigated. Mirror polished SUS304 substrates were preheated in a range from 300K to 550K. Ambient pressure was controlled in a range from 1.5kPa to 101.3kPa. Powder materials, Ti, Cr, Ni and Cu with purity 99%, were sprayed onto the substrate surface to examine the influence of the material physical properties on the flattening. Splat morphology changed from the splash shape to the disk one with decrease of ambient pressure and increase of substrate temperature. The material, which forms oxide easily, has a tendency in forming disk splat preferentially. It was found that wettability of the substrate by the sprayed particles may dominate the flattening.

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Cold spray is a promising technique to produce high quality metallic coatings. However, the details of deposition mechanism have not been understood yet. This study investigates the deposition mechanism of cold-sprayed stainless steel particle to a stainless steel substrate with different feedstock particle size. Spraying of larger particle size of feedstock had advantages for the deposition efficiency and the adhesion strength. It is due to the shock wave formed in front of the substrate surface. The particle velocity of smaller particles were rapidly decreased through the shock wave and lost their performance. Individual particles collected on the substrate (known as splat) clearly revealed the phenomenon. The original particle size was different for each feedstock, but the splat size was almost similar in size. It means that the smaller particles couldn't penetrate the shock wave and only the larger size of particles could deposit.

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Fluoropolymers have very low friction and various unique properties. Therefore, they are expected to be applied for sliding materials. However, because of the insulation, it is easy to accumulate static electricity. Hence, to apply to sliding materials there is need to provide electrical conductivity. Nano Carbon is expected as one of the conductive fillers that can effectively improve the electrical property by a small amount of addition, so many researchers studied about composite materials filled with nano carbon. However, because nano carbon is easily agglomerated, the problem that steady electric conductive cannot be obtained is pointed out. In this study, we prepared Carbon nanofiber (CNF) filled Polytetrafluoroethylene (PTFE) films by spin coating method, and evaluated the surface resistivity of the composite film and dispersion status of CNF, and investigated relationship between electrical conductivity and dispersion status of CNF. As a result, when the condition of ultrasonic dispersion is optimized in the case of 2wt% CNF/PTFE composite film, by optimizing the conditions of ultrasonic dispersion process, the surface resistivity of composite film has decreased to 1/100 compared with no dispersion process.

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Although the plastic strain induced in materials increases the fatigue strength, it may reduce the fatigue strength due to a stress concentration part in the components. In this study, damage behavior of notched part of austenitic stainless steels subjected to overload was investigated. The change in the Vickers hardness and hole shape due to plastic strain were examined for Type 316L stainless steel. The degree of plastic strain became severe around the holes and damage of stress concentration part is heavier than that of smooth area.

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Moulding of aluminium foams from a solid bar including a foaming agent is examined. Aluminium powder mixed with a foaming agent is formed to a solid bar by hot extrusion. The solid bar is extruded into a mould by using the heated die for foaming of aluminium, and then the mould is filled with the aluminium foam from the heated die. The experiments using cylindrical moulds of different aspect ratio of height to diameter for different moulding directions are conducted. In moulding horizontally, the aluminium foam extruded from the heated die tends to go down in the mould due to self-weight when the mould diameter is large. In the case of small diameter, the aluminium does not expand enough in the mould due to friction by increasing contacting force. The volume fraction of aluminium foam to the mould inside becomes large under appropriate conditions of the aspect ratio of mould shape and the moulding direction.

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Ultrasonic welding is an attractive joining method, because bonding is quickly obtained without extra heat or welding metal. Thus far, there have been several researches about the bonded interface structure and process of the ultrasonic welding. However, there were only few studies about the application of ultrasonic welding to the Al/Glass substrate and detailed bonding mechanism was unclear. In this report, ultrasonic bonded interface between an Al wire and a glass substrate was observed by high resolution transmission electron microscopy. The bonded sample was cut perpendicular to the interface and, the atomic structure and chemical composition of the cross-section of the sample were analyzed. Around the interface between Al and Glass, several dislocations and Al sub-grains were produced in Al and no intermetallic compounds were observed. Al and Glass were directly connected at the interface. This indicates that dislocations generated at the interface moved to form low angle grain boundaries during a recovery process without intermetallic formation.

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The sleeve riveting method is the fastening process by which the plate parts are fastened with bolt and nut formed from the sleeve by using the swaging tool. The fastening performance of this method is influenced by the material flow of the sleeve into the thread grooves of a bolt. A series of experiments on the sleeve riveting process were carried out in the plane strain condition in order to observe the material flow of the specimen different in thickness of the sleeve and with or without the notch. In this research, it is clear that the punch load depends on the thickness of the sleeve and decreases due to the existence of the notch and that the notch influences the filling of the sleeve into the grooves of a bolt.

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Effect of sucrose removal treatment on the mechanical properties and process ability of natural fiber composites was investigated. Bagasse, which is by-products in sugar mill was used as a natural fiber with polypropylene. The bagasse was washed by warm water and provided to mixture the matrix, and fabricated with a press forming. As a result, sucrose was found to be 4% in the original bagasse. The remained sucrose caused the bagasse carbonization and un-dissolved tar component on the mold in the press forming above 190°C. After removal of the sucrose, both the carbonization and the tar was dramatically reduced. The relationship between water treatment and the remained sucrose was also revealed.

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In this paper, an approach to improve in sensitivity for detecting the phase-transformation (crystallization) of a thin film amorphous alloy is introduced. In combinatorial method for evaluating the crystallization temperature of thin film amorphous alloys using thermography, the crystallization is detected by change in thermal emissivity due to crystallization of the amorphous sample. In general, the emissivity is known to be dependent on material, and its surface conditions (for example, oxidation, and roughness). This study focused on surface roughness of the sample, the influence of the sample surface roughness on the change in the apparent emissivity due to the crystallization of the sample was examined. As results, the rate of the change in the apparent emissivity is amplified by adjusting the surface roughness, and the detection sensitivity of the transformation can be improved.

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The combinatorial deposition gives the desired material exploration more efficiently to have samples having various compositions. The combinatorial deposition with New Facing Targets Sputtering (NFTS) is useful to create the new materials. The new method of the material exploration is offered in this research. It took a survey of the change of the composition distribution with that of the depositing conditions in NFTS; the output power applied to the target material, Ar pressure in the apparatus, TS distance. In this process, the samples with gradient compositions were made and measured composition distribution. The change in the output power resulted in that of the composition range. The gradient composition is influenced a great deal by the changes in Ar pressure and TS distance.

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We proposed novel high-throughput characterization method of crystallization property of thin film amorphous alloys for combinatorial searching approach. Crystallization of integrated, deposited, thin and tiny amorphous alloy samples can be detected at once by a commercial thermography as changes of their emissivity. In this report, high-throughput characterization of crystallization temperature (Tx) was demonstrated using three thin film libraries on which compositional distributed PdCuSi thin film amorphous samples were deposited by combinatorial arc plasma deposition. As a result, Txs of 285 samples were evaluated and it took only 14 days. Two Txs selected from the all 285 evaluated Txs were compared with results of conventional method, differentials scanning calorimetry. The maximum difference of the two methods was 8K. In terms of throughput, the proposed method achieved 10 times speed than the conventional method and 66% reduction of characterization time. From these results, the proposed method is powerful tool for combinatorial searching for novel thin film amorphous alloys.

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Time-dependent crystallization property of thin film amorphous alloys is important because it provides an indication of lifetime of the alloys. We propose a novel and high-throughput method for characterization the property. The method consists of integration of temperature condition and detection of crystallization by a thermography. The integration can be achieved using temperature-gradient heating furnace system which can maintain the heating gradient on thin film sample. Crystallization of the temperature gradient sample can be detected by the thermography as emissivity change in various points at once. The method is demonstrated using two compositions of NiNbZr thin film amorphous alloys integrated on one substrate. Time-temperature-transformation diagrams of crystallization can be obtained by one heating test. Furthermore, activation energy of these alloys can be calculated by the results. Throughput of the proposed method is 3.5 times higher than conventional method and it is possible to reduce characterization time by 72% in the case of the above demonstration.

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Friction stir incremental forming method developed by the authors was applied to forming A2017 aluminum sheets.The dimensions of 100 x 100 x 0.5 mm^3 aluminum sheets were employed for specimens. Forming conditions, tool rotation rate and tool feed rate, were changed and formability was evaluated. When the tool rotation rate was 8000-10000rpm and the tool feed rate was 3000 mm/min, the minimum half apex angle of 25° this coincides with themaximum elongation of 137% was obtained. Formed parts were artificially aged and Vickers hardness test was performed. As aging time increased, the hardness was decreased to 70 HV in the final. This means forming did not clear the pre-aging processing or complete full aging. The tensile strength of formed parts were about 280MPa which was theintermediate value between as received one of 373MPa and fully aged one of 200MPa. From the microstructureobservation, the grains were fined by forming but some voids and impurity were found.

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Adhesive bonding is now widely used in manufacturing portable electronic devices such as mobile phones. Recently, with the aim of improving efficiency of its manufacturing process, pressure sensitive adhesives (PSA) for the joints are taken notice instead of liquid adhesives. However, the strength of PSA bonded joint, especially under impact loading, has not been understood enough yet. The main scope of this study is to research the strength of PSA bonded joint under various loading rates. In these experiments, stress distribution in specimens is visualized using high speed polarization camera. These experimental results show that although the fracture toughness of PSA bonded joint increases with respect to loading velocity in slower rate range, it decreases in higher loading rate range because PSA becomes more brittle.

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The use of adhesive bonding has recently been expanding to join metal panels. However, pre-curved metal adherends can cause residual stress, and it leads to the fracture of the joints, especially at high temperature caused in paint baking process for instance. The purpose of this study is to establish a method for predicting the fracture phenomena of joints bonded with a second generation acrylic adhesive (SGA) at high temperature. The stress-strain curves of the adhesive at various temperatures were measured experimentally. The debonding process of the joints, which had pre-curved adherends having constant curvatures, was also investigated experimentally. The deformation of the adhesive layer was predicted analytically using Dillard's model and finite element method. The debonding temperature was also predicted based on the stress-strain curves and the analytical results. The predictions showed fairly goof agreements with the experimental results.

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The influence of the injection parameters and Carbon addition on the mechanical property of magnesium alloy products made by injection molding method was investigated. Test pieces were cut out from the plain plate made of AZ91D or AZ91D+Carbon Mg alloy, which was molded in a metal die by using a Thixomolding machine. The test piece, whose thickness was 2.5 mm were examined. The mold and barrel temperature was kept to 483 and 893 K, respective. The gate velocity was varied between 11.6 m/s and 37.7 m/s. The test piece was mechanically characterized under tensile and bending load. The result of tensile test showed that the tensile strength was increased not only with increase of increase of gate velocity, but also with increase of Carbon content. The bending strength of AZ91D was also increased with increase of the gate velocity, however it decreased considerably at the low gate velocity condition when Carbon was not added. On the other hand, the bending strength of AZ91D+Carbon was almost constant when the gate velocity was changed. The bending strength of AZ91D+Carbon was increased when Carbon was added with 0.1 mass % of concentration. However, the excessive amount Carbon (over 0.1 mass%) was not effective to improve the bending strength. These results suggested that the addition of Carbon with appropriate content was effective to improve tensile and bending properties of AZ91D.

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The detail investigation of the flow stop data is necessary to reveal the flow stop mechanism. In this study, the fluidity of ADC12 alloy was investigated by using the vertical suction type test apparatus. Molten metal was sucked into test section (rectangular channel dies) under carefully controlled conditions. The influence of mold temperature on fluidity length was examined. Test results showed that the fluidity length decreased with increase of the mold temperature. The difference between was also decreased with increase of the mold temperature. The contact area of the molten metal and the mold was increased with increase of the mold temperature. When the mold temperature was low, the dendrite micro structure around the surface of shrinkage part was coarsened. The time taken for flow stoppage saturated at elevated mold temperature. According to mold temperature increases, the average velocity of molten metal was decreased due to decrement of fluidity length and increment of the time taken for flow stoppage.

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Microstructural and mechanical properties of the extruded a-13 duplex phase brass alloy with elemental Mg powder were investigated in this present study. Pre-mixed Cu-40Zn powder with 1.0 mass% pure Mg powder (Cu-40Zn+1.0Mg) were mixed and consolidated by spark plasma sintering (SPS). SPSed Cu-40Zn+1.0Mg consisted of a+0 duplex phase containing CuMgZn intermetallic compounds (IMCs) with a mean particle size of 10 gm in diameter. The IMCs were completely solid soluble in the a+P duplex phase by the heat-treatment at 973 K for 15 min. The SPSed Cu-40Zn+1.0Mg was pre-heated at 973 K for 15 min and immediately extruded. The extruded specimen had fine a+p duplex phase, containing fine precipitates of the above CuMgZn IMCs with 1.0 ium in diameter, instead of the coarse CuMgZn IMCs. The a+13 phase grain size was an average value of 1.99 gm acquired by electron back-scattered diffraction analysis. The tensile properties of the extruded specimens were an average value of yield strength: 328 MPa, ultimate tensile strength: 553 MPa, and 25 % elongation. The extruded Cu-40Zn+1.0Mg revealed the high strength properties. The high strengthening mechanism of the wrought brass alloy was mainly due to the grain refinement of a and P phases because of the pining effect by the fine CuMgZn precipitates in the boundaries of each phase.

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Kyo-Gawara is one of traditional crafts, one of Japanese roof tile made in Kyoto by using traditional techniques. The characteristics of Kyo-gawara are gloss on surface available in "Migaki" process. Migaki process is that craftsman strokes half-dry surface with paddle one by one. Two craftsmen having different career participated as subjects, motion analysis during Migaki movement were performed. As a result of motion analysis, Expert took less time to finish Migaki process than nonexpert. Number of time for stroking surface of expert was less than nonexpert.

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\"Kirikane\" is a traditional decorative techniques using metal foil cut into long thin strips, triangles, and squares. Today, traditional arts are facing on difficulties of finding successors. Especially, Kirikane, needs successors. Finding out the secrets help craftsmans to hand down the tacit knowledge and groom successors easily and quickly. The purpose of this study is finding out the "Kirikane" craftsmans' tacit knowledge by using motion analysis technology. In this study, we aimed at "Hakukiri", cutting foil, and found that "Kirikane" craftsman do the same motion regardless of the thickness of the cut foil.

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A Japanese paper that is made in Saijo city is called "Saijo-Japanese paper", which is one of traditional crafts in Japan. One of the main characteristics of the Saijo-Japanese paper is a crape structure. The crape structure is made by craftsmen's hand. Weakening demand for the Saijo-Japanese paper is required to create new products by using the Saijo-Japanese paper. The illuminator using Saijo-Japanese paper is proposed as one example. However, light transmission properties of the Saijo-Japanese paper are not clarified. In this study, the crape structures and the light transmission properties of the Saijo-Japanese paper with various making condition were quantified. The light transmission properties were affected by the crape structures.

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Kyo-wall is Japanese traditional technology creating calm and natural room atmosphere, supported by simple materials (clay, vegetable fiber and water), human skill succeeded for more than 400years and some kinds of trowels. We have found the significant flow differences of kyo-wall compound according to trowel materials with high speed VTR image analysis. In this report the peculiar high flow of Kyo-wall compound on old Mizunaze trowel by Japanese sword specialist against on current trowel will be presented, and especially smooth flowing and deformation in mixing process and smooth sliding on the trowel surface in transferring process to wall will be discussed. This shows that the secret of hand made tools harmonized with material processing should be still hidden in traditional technologies.

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Bio- Fuel Cell is promising technology to overcome global issue. But there are many problems in Bio-fuel cell using organism catalyst because research of this type of fuel cell is started in only few years. Purpose of this research is to obtain high electric power using new type of electrode in Microbial Fuel Cell (MFC). First, O.R.P (Oxidation Reduction Potential) in anode and cathode of MFC were measured to understand parameters determining E.M.F (Electromotive Force) in MFC. We use graphite plate as the electrode. At first, it is clarified that pH, concentration of glucose and yeast, and mass of yeast determine E.M.F of MFC. Moreover MFC showed high power using the electrode sputtered by Ar. In addition, the electrode painted CNT (Carbon Nanotube) by Ag pastel make MFC generating high current density and high power.

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Recently, carbon fiber reinforced plastic(CFRP)laminate is used for structural parts of airplane, car, and so on,because it has high specific intensity, high specific stiffness and high chemical resistant. However CFRP is difficult tobe drilled clear holes. Moreover, cutting tool is easily worn out with each drilling. The more cutting tool is worn, themore delamination of CFRP is easy to occur. This paper describes the attempt of electric discharge assisted drilling ofCFRP to improve the quality of drilling holes. Cutting experiments were performed using tungsten carbide drills 6.Omm in diameter with electric discharge. Electric discharge enhanced drilling may have effect to reduce delaminationbecause electric discharge damages the carbon fiber and decreases the thrust force of drilling to cut the carbon fiber. It isrequired to optimize the electric discharge power in future work. Because in the high power case, epoxy resin is burnedand in the low power case, carbon fiber is not damaged.

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Aluminum die-casting (ADC) is light and functional material that is extensively used in car parts for lightweight solution. But, joining ADC and other metal is difficult, because ADC is brittle, low-thermal conductance and low electrical resistance materials. So, previously, bolts and nuts joining which is expensive and troublesome are used for ADC. Therefore this is obstacle for popular use in low-end car. In this study, we apply metal flow joining to ADC joining focus on property that in compression state even brittle material has ductility. At first, we investigate plastic deformability of ADC in compression state. Next, we set some parameter of ADC ring width, punch width, punch angle and groove shape, and experienced axial and circumferential direction strength test to optimize metal flow joining. As a result, ADC strained up to 18% in compression state. Therefore, ADC can apply to metal flow joining. And, Metal flow joining's strength is related to metal flow volume.

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Clinching is one of a remarkable joining method for aluminum sheets because of its high productivity, recyclability and possibility to reduce costs. We have studied about the effects of ultrasonic vibrations on the improvement of peeling strength of clinched joint. Through this study, we found a remarkable phenomenon named stirring phenomenon by ultrasonic stress vibrations; in case ultrasonic stress vibrations were applied to clinching tools, vertical material flows were created and materials were stirred and unified finally. This phenomenon can be a core technology for a new joining method and a new grain refinement method. Therefore, clarification of generation mechanism of this phenomenon is required. In this study, thin aluminum sheets were clinched under various conditions of ultrasonic vibrations. And we observed metallographic changes in the earlier stage of the vortex initiation. As a result, the location where the driving force of stirring effect was generated was revealed. And mechanism for generation of this driving force was discussed considering a unique metallographic structure.

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Quasi-equilibrium Lattice Boltzmann model (QELBM) has been developed in order to get stable solution at high Reynolds number flow simulation in recent years. Since QELBM uses only two relaxation times to stable the calculation, the algorithm is simpler than MRT, which is the model often used to stable the solution, and 13 velocity model for 3-dimensional calculation, which cannot introduce in Entropic Lattice Boltzmann model, can be used. However, the Application of QELBM for 3-dimensonal flow has not been done yet, thus the detail of the advantage of QELBM for other methods is not known. In this study, we applied QELBM to flow in a Cubic cavity in Reynolds number Re = 100,400 and 1000, and investigated the stability, accuracy and computational effort by comparing with 13 velocity MRT and 19 velocity LBGK model. As a result, it was found that QELBM can efficiently calculate the flow with equivalent computational stability and accuracy to the other models.

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The direct numerical simulation for curved turbulent channel flows with several spanwise system-rotation is performed. Near the convex wall, the flow is stabilized with the positive rotation and is destabilized with the negative one. On the other hand, the flow field near the concave wall becomes stable with the negative rotation and unstable with the positive one. The profiles of the mean quantities are standardized by the effective rotation number including the curvature effect. The Goertler vortices are present under the strong rotation and curvature cases.

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The direct numerical simulation for MHD homogeneous shear turbulence under the streamwise system-rotation isperformed. There are small differences for the kinetic and magnetic energy, Reynolds and Maxwell stresses in theseveral streamwise rotation cases by comparison with the results of the spanwise rotation MHD field. Immediately afterthe calculation start, however, the contribution of the energy transformation becomes large as the rotation increases.From the kinetic energy spectral budget it is found that the sum of the transfer and transformation spectral functions isbalanced with the dissipative one in the small scale.

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Circuit breaker is an apparatus that interrupts current and plays a role in control and protection of power system. As the need for electricity rises and high voltage power transmission, a large current interruption at the accident in addition to usual current opening and shutting is demanded for securing stability in the system. Due to the excellent insulation and current interruption properties of SF6 gas and the simplicity and high reliability of unit structure, auto-expansion type SF6 GCB (Gas Circuit Breaker) are generally used. Moreover it has the advantage in reducing operating energy. However its efficient design need a detail understanding of the fluid-plasma interaction phenomena associated with the gas blast characteristics. In the fluid-plasma interaction process, turbulence mixing between the high temperature arc plasma core and the surrounding fluid plays a dominant role. Therefore the main of this research is to study the fluid-plasma interaction phenomena based on a High-Order LES turbulence model. In this study, gas flow in a Laval nozzle in the presence of thermal arc in between the electrode placed in a nozzle is numerically simulated and followings are obtained. The heating of gas in the arc core region resulted in expansion of the gas, which in turn caused the occurrence of the movement of pressure wave-front towards upstream and downstream direction and the pressure near both the electrodes tip region increases. These phenomena led to emanating high velocity jet from the electrodes tip portion towards upstream and downstream directions in arc core region.

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A large eddy simulation was implemented to investigate the effect of the degree of overbite, which refers to the extent of vertical overlap of the maxillary central incisors over the mandibular central incisors, on the flow in the simplifiedoral cavity model that morphologically simplifies the oral cavity when sibilant was produced. The result illustrated thathigh Powell's sound sources were generated along the upstream surface of the upper obstacle to which a flow separatedfrom the lower obstacle impinged and in the separated flow from the edge of the upper obstacle. Extension of theoverbite resulted in enlargement of the regions of large Powell's sound sources in those regions.

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The fiber consistency of papermaking pulp-suspension flow has been investigated experimentally. The measurements were made by the optical method which has been developed by the authors(2010). DisUibutions of time-averaged andnuctuating fiber-consistencies of pulp suspension in ducts were obtained and illustrated. On the basis of the results,characteristics of the pulp suspension flow were examined. Simultaneously, discussions were given on the transition of five patterns found for pulp suspension flows. The degree of uniformity of the fiber consistency, that is suggested as the standard deviation of its distribution, is decreased from 0.3 to 0.05 with an increase of velocity for the test pulp suspensions of Cs=0.4〜0.8%.

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Gas-liquid two-phase interfacial flows, such as the liquid film flows (also known as wetting flows on walls), are observed in many industrial processes including absorption, distillation and so on. The present study focuses on the characteristics of wetting flows, in particular the drastic transition between the film flow and rivulet flow, as the liquid flow rate and the wall surface texture treatments are varied. The three-dimensional gas-liquid two-phase interfacial flow simulation is based on the volume of fluid (VOF) model. As the liquid flow rate is increased and then decreased, a hysteresis of the transition between the film flow and rivulet flow is discovered, which implies that the transition phenomenon depends primarily on the history of the change of interfacial surface shape (which affects the process of the flow regime transition). Further study on the effect of texture geometry shows that the surface texture treatments added on the wall can impede liquid channeling and increase the wetted area.

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With computational fluid dynamics (CFD) and experiments, we studied the spiral flow and mixing process inside a novel cylindrical micromixer. Because mixing efficiency is generally poor in microflows ,we expected spiral flow to enhance mixing. Parametric studies evaluated mixing efficiency in terms of flow rate and outer cylinder diameter (i.e., channel width). The patterns of streamlines and the concentration distribution obtained by CFD simulations agreed well with those obtained experimentally by flow observation and concentration measurements. Moreover, we found that the mixing efficiency was strongly influenced by the number of revolutions of the spiral flow. Consequently, we found that as flow rate was increased, the spiral-flow revolution number increased, which resulted in an enhanced mixing efficiency.

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The micromixer, which has a rotor with a curved channel, is studied experimentally. The secondary flow in a curved channel of square cross-section is investigated using PIV (Particle Image Velocimetry) and LIF (Laser Induced Fluorescence) method. 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 channel curvature 6 = aIR is taken to be about 0.1, where 2a is the width of the channel, R the curvature radius of the channel. Other non-dimensional parameters concerned are the Dean number De = Re61/2, where Re = Q1(2av) is the Reynolds number, Q the flux, v the kinematic viscosity, and the Taylor number Tr = 2a2S2(26)1/2/(6v), where is the angular velocity of the rotor. 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 achieved in the case of De < 0.11 Trl and for that case secondary flows show chaotic behaviors. And then we have confirmed the occurrence of reflux of main flow.

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The cylinder rotating around horizontal axis was put on the table rotating around vertical axis. The inclination and collapse phenomena of the vortex were observed while changing the speed of rotating table and rotating cylinder, the length of test section of cylinder and viscosity of test fluid in this experiment. The vortex in the rotating cylinder inclined in the directions upper right or lower right by the effects Coriolis' force. As the speed of rotating table was increased, the vortex collapsed. But when the viscosity of test fluid was high, it did not collapse even if the speed of rotating table was increased.

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In the present study, validation of discretization of Navier Stokes Equations of the OpenFOAM was investigated. The authors computed a flow over a flat plate by using the OpenFOAM and the result was compared with theoretical solution of the Blasius equation. The computational domain is rectangle, with its height of 0.5m, width of 0.4m, and the distance along the flat plate of 0.3m. The grid number over the plate were 200 X 300. 50 grid points in the x-direction were located upstream of the leading edge of the flat plate. The first gird points above the wall had height of 80 X 10-6m in the y-direction. The free stream Mach number was set at 0.3. The simulated velocity distribution in the boundary layer was well compared with the theoretical one. However unrealistic overshoot the velocity at the edge of the boundary layer was observed. Further investigation is needed for overshoot of the velocity.

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A priori test of the one-equation subgrid-scale (SGS) model for turbulent compressible flows with the coherent structure model function proposed by Kobayashi is performed by the direct numerical simulation (DNS) data for the turbulent compressible channel flow with the isothermal and adiabatic walls. As a result, the correlation between the SGS model and filtered DNS data is poor. However, the model expressions for the GS stress and flux, SGS temperature-dilatation terms reproduce the filtered DNS result. Near the wall, it is found that the SGS stress-strain term is effective.

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Thermal spraying is one of the successful surface processing method that gives restoration or a new function on various mechanical components. The thermal spraying process accelerates the solid particle by a high temperature and a high velocity gas stream. After impacting on the surface of the substrates, the particles are formed into a coating. The present study is a gas-dynamic research on a cold spray, which is a cutting edge coating method. The cold spray process makes the solid particle impact on the substrate at a high velocity by a supersonic gas flow in the state of the solid phase to form a coating. It is experimentally clarified that the particle starts deposition on the substrate when particle velocity exceeded a critical velocity. Therefore, it is important to clarify the particle behavior. In this study, the influence of the loading ratio on the gas flow and the particle behavior is examined by quasi-one-dimensional analysis that assumes two-way coupling. The calculated results reveal that the gas velocity and the particle velocity decrease as the loading ratio is increased.

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Cold spray is one of the thermal spray technologies to make a coating. From the practical point of view, the deposition efficiency, which is the ratio of the deposited mass on of the particle against the sprayed mass of the particles, is an important parameter. In the present study, the effect of the nozzle shape on the gas flow field and deposition efficiency is clarified by numerical simulation. The calculated results reveal that 1) The boundary layer separation occurs at the upstream even though the flow is accelerated immediately in the nozzle that was designed by the method of characteristics.2) The adhesion rate of a relatively small particle rises in the nozzle designed by the method of characteristics, and the adhesion rate of a relatively large particle rises in the conical nozzle.

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The purpose of this study is to investigate the pressure pulsation in piping systems with a discharge opening under water excited by a blower and its technological application. The effect of the cross-sectional area at the discharge opening was estimated experimentally. Both the pressure and the flow-rate in the piping systems were measured for various parameters such as the depth of the discharge opening, the number of revolution for the blower, and the cross-sectional area of the opening discharge. It was clarified that the amplitude of the pressure pulsation in the piping systems has the maximum value for the cross-sectional area at the discharge opening. The discharge pipe with the exhaust valve is effective against the rise of the instantaneous pressure in the piping systems.

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The purposes of this study are to develop pumping capability of a covered wire-parallel plate type EHD gas pump and to give the optimum design guideline. In this study, experiments have been conducted to study effects of positive and negative dc applied voltage on time averaged discharge current, gas velocity, volumetric flow rate and efficiency for single stage (single wire) EHD gas pump having different channel widths and the multistage (double wire) EHD gas pump at atmospheric pressure and room temperature, where air was used as the working fluid. Experimental results show that: (1) Depending on channel width, the number of wire electrodes and distance between wire electrodes, a maximum gas velocity, volumetric flow rate and efficiency considerably changed and (2) Stable discharge was observed under only positive applied voltage.

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Fans and blowers are used in many kinds of industrial fields. The targets for the development are high efficiency, low costs, high reliability and low noise. The reduction of the noise is one of the most important issues for the axial fan. In this research the effect of the blade sweep on the performance and the flow field is investigated by using CFD. By using the results of the numerical study, y500mm prototype axial fan is manufactured and carried out experiments for performance and noise. The effect of the sweep on the performance and the noise are clarified. The influence of rotating stall and back flow on the noise is experimentally clarified.

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Occurrence of ice accretion in a jet engine causes aerodynamic performance degradation, and may lead to serious damage to stator vanes and compressors when ice comes off and penetrates inside the jet engine. In particular, ice accretion on a pressure side of fan blade in a jet engine is a significant matter, and it is thought that location and amount of the ice accretion are closely related to stagger angle of the fan blades. In the present study, super cooled water droplets generated by a spray nozzle were drawn in an axial fan in a temperature controlled room, and observations and mass measurements of ice accretion on the fan blade were carried out with different stagger angles. Results revealed that ice accretion decreased on a pressure side of fan blades, and increased near a leading edge on a suction side of fan blades with a small stagger angle.

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The purpose of this study is to understand the icing phenomenon on the fan blades in freezing fog, and to develop the anti-icing technology. The growth of icing on a blade was observed , and the mass of icing was measured on each blade with different surface properties , contact angle and surface roughness. As the results , the relations growth of icing and decrease of air flow rate were clarified , and it was found that high contact angle and low surface roughness had high effect for anti-icing.

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