As shortened development period has been recently requested to every companies, the simulation models of each project are usually used for this purpose. However, actual models such as automobile and aircraft require new modeling method exceeding mechanic and electric fields, which is too large to make a full modeling by the conventional method. This new method can make same modeling between mechanical and electrical systems by equally dealing with force and current as intensive quantity, velocity and voltage as extensive quantity. Moreover, the simultaneous modeling with an electrical and mechanical properties is conducted and compared with an experiment data. As a result, it is found that the simulated angular velocity is nearly equal to the value obtained by the experiment, excluding rising phase and the accumulation angle is nearly equal to the value obtained by the experiment.

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Human arms or legs, by repeating inappropriate motion, even as it little by little, may cause serious disorders. In recent years, wearable motion amplification devices, to support human walk or sports training, are in development. However, these existing devices are only interested hi the large movement of the human body, and these device motions are simply. Therefore these device may cause the above such problems. This paper describes the development of a wearable wrist motion training device using the parallel link mechanism. Training device utilizes a shaft motor as an actuator. Therefore, this device is flexibility like fluid actuator, and can control easily like motor. The adoption of parallel link, it is possible to measure the motion of the wrist. In addition, it is possible to teach the details of articulation motion. In experiments, the teaching training of flexion-extension movement of the wrist joint are carried out using the training device, and has been confirmed that the motion has been properly taught to trainee.

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Control Moment Gyro (CMG) is a momentum-exchange torque generator. Although CMG has the advantage of large output torque, it has a serious problem called singularity. Because singularity changes in accordance with the number and placement of CMGs, when CMGs of original system are in failure state, singularities of a CMG system consisting of the remaining CMGs are different from that of the original CMG system. In this study, we visualize singularity surface of various fault patterns of the Five Pyramid Configuration (FPC) CMG system which placed CMGs on five cants and one top face of a regular dodecahedron, and consider the way to determine optimal angular momentum trajectories using singularity surfaces.

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Recently, mounting technology for small electronic chip parts becomes increasingly important for portable devices and MEMS devices. Multi-axial linear stages inside conventional surface mounting technology instruments are much larger and heavier than tiny chip parts. Because the linear stages require linear guides, bottom stage must carry upper stages including their linear guides. Recently, we have developed light-weight holonomic inchworm mobile mechanism which is composed of a pair of electromagnetic legs and four piezoelectric actuators. Because it requires expensive ferromagnetic working table with well-polished surfaces, its positioning range economically limited less than 0.4m^2. In this research, we describe newly-designed alternate-tripod-type inchworm mechanism driven by piezoelectric actuators with displacement magnification mechanism, so that it can move on the non-magnetic surfaces. The mechanism is also designed to have 6 load cells for detecting vertical force between each leg and floor for balancing then- frictional forces.

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This study is concerned with wet clutch. The purpose of this study is visualization of fluid hi ditch of a clutch and analysis of velocity in PFV. Experimental device consists of a fixed clutch and an acrylic fiber cylinder which is around the clutch revolved. The distance between the disks are 3mm. Number of rotation is 300 rpm. The width of the clutch ditch are 2mm, 4mm and 8mm. As experimental results, when the ditch width was 2mm and 4mm, the radial velocity (U) was dominant. However, when it was 8mm, peripheral velocity (V) became dominant. In the case of 8mm, the velocity of the depth direction may have.

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The structure that oil is supplied from the center of a shaft to gear face through a hole machined at gear bottomland is widely used in forced lubrication type gearbox. The hole is sometimes used for supplying oil from the gear face to a needle roller bearing located at the center of the gear in bath lubrication. In this case, the oil flow is opposite to centrifugal force and thus, it becomes complex. This phenomenon is important because it affects to the lubrication of the bearing. The purpose of the study is to clarify the oil flow qualitatively and quantitatively. In this paper, the flow pattern is visualized using acrylic gear as a first step of the study. The flow pattern is changed by hole diameter and gear rotation speed.

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We have developed a micro crossed helical gear endurance test system. In this study, we performed the acceleration test of relatively small module spur gear. Then, based on the result, we evaluated endurance test system and test gears. From the result of the experiments, we obtain the following results; (1) We developed a micro crossed helical gear endurance test system. (2) With the increase in rotational speed, the maximum temperature rise of the gear neighborhood tends to increase. (3) In the range of the experimental condition in this study, damage of tooth surface or partial contact was not confirmed.

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This paper aims to control a traction-drive stepped variable transmission which slides the roller surface during shifting. Its μ-V characteristic varies largely with respect the frictional heat caused by the sliding, and hence the conventional shift control does not always achieve good ride comfort. In the proposed control system, during the inertia phase, the revolution response of the driving motor is controlled with respect to its status change in order to prevent the friction coefficient from changing faster than the time response of the variable speed motor (ACTR), and simultaneously, the pressing force dominating the ride quality is controlled with predicting the time change of the friction coefficient in order to reinforce the tracking performance of ACTR. The experimental result of the practical vehicle demonstrates that the proposed control system allows the traction drive to shift more smoothly and quickly than the gear transmission.

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This research studied the effects of concentration of ZnDTP additives on the tribological properties of a H-free DLC film under boundary lubrication with oils that contained organic friction modifiers. The tribological properties were evaluated using the reciprocating type cylinder-on-disk tribo-tester. ZnDTP and two types of organic additives glycerol mono-oleate (GMO), and tallow diethanol amine (TDEA) were added to poly-alpha olefin (PAO). Friction tests were conducted on the DLC/DLC tribo-pair under lubrication with PAO and PAO-based oils containing GMO, TDEA, ZnDTP, GMO + ZnDTP, and TDEA + ZnDTP additives. For friction test, the friction coefficient of H-free DLC film lubricated with GMO containing oils increased as the concentration of ZnDTP additive in oils increased. On the other hand, H-free DLC film lubricated with TDEA containing oils exhibited ultralow friction coefficient approximately 0.03-0.04 regardless of the concentration of ZnDTP additives.

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An experimental apparatus has been developed to investigate transient phenomena in contact area between an elastic belt and a rigid cylinder. It employs a contact area between a transparent flat belt (polydimethylsiloxane) and a transparent cylinder (glass) for optical and photoelastic observations. It enables simultaneous measurements of (1) "contact area" from optical images captured by a high-speed video camera, (2) "internal stress" from photoelastic images captured by the high-speed video camera, (3) "external forces" measured by two load cells mounted at the ends of the belt, and (4) "friction-induced noise" measured by a microphone. By using the information obtained by the apparatus, we can identify when and where the friction-induced vibration and noise were generated in the contact area.

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Tapered rolling bearings are applied for supporting differential gears in most vehicles. Though it is categorized as radial bearing, it is required that an axial load should be applied as preload to support the radial load by reason that the inner ring and the outer ring can be separated. However, when the tapered roller bearing is subjected to axial load, the friction at the time of startup becomes large and wear intends to arise, because sliding friction occurs between the roller end face and the large flange face of inner ring at which the axial load is applied, hi case of fixed position preload, the assembly height reduces due to the wear and the amount of preload dwindles. This phenomenon is called 'pre-load loss' and there is no report on the pre-load loss. This study explained the relationship between the taper and the pre-load loss and the relationship between the assembly height and the pre-load loss with observing the change of preload when the tapered roller bearing was rotated by fixed position pre-load.

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It is important that the screw tighten by fair tighten force. But, it is a difficult that we control the force of tighten screw. Further functional decline and unusable loosening screws by vibration or impact is become a problem, because the small screw is vary widely, tightened relatively easy. In this report, I did the tightening characteristic of high-tension small screw if targeted for experiments. I performed the tensile test to confirm tensile strength in case of shape of screw. In addition, I performed the tightening test of the tightening characteristic of high-tension small screw. As a result, we got a new knowledge about tighten characteristics of Tightening characteristic of high-tension small screw.

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This paper describes water hydraulic proportional flow regulating valve to control a water-driven linear stage at constant low speed for ultra-precision machining. To keep speed of the water-driven stage constant, it requires keeping flow rate through the valve constant even if the pressure difference across the valve changes by a fluctuation of supply pressure or a load to the stage. Therefore, a pressure-compensation valve and an invariable restrictor are connected to the upstream of an electromagnetic proportional valve in series. Characteristics of the electromagnetic proportional valve and pressure-flow characteristics of the invariable restrictor were measured and they were included hi the mathematical model. The static characteristics of the valve were measured and compared with the simulation results, then validity of the design was examined.

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There are numerous accident occurs at signalized intersections. Dilemma-free control is one of the countermeasures to prevent accident at signalized intersections. In this paper, a driving assistance system during amber at signalized intersections is proposed. The system enables driver to stop relatively small deceleration when encounters dilemma during amber at signalized intersection. The driving assistance system is implemented on a driving simulator and an example of collected data with proposed system in experiment is mentioned.

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This paper described basic study of a resonant cavity applicator with a monitoring system using an ultrasound imaging system. In our previous study, we reconstructed a 3-D model from a 2-D ultrasound images to detect the location and size of the target and to calculate temperature distributions inside the 3-D model. From the results of computer simulations, we estimated the suitable condition for heating target efficiently. In the present paper, first, we performed heating experiments of the agar phantom using the suitable condition for heating target efficiently. Second, a comparison of the estimated temperature and estimated temperature was presented. From these result, we found that the proposed system is useful for effective hyperthermia treatments.

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This paper describes a method of light-weighted on seat sliding rail by analyzing the changes of the force transmission from seat belt to seat sliding rail. It consists of three phases: (i)modeling the human body, the seat belt and the seat. (ii) dividing the movement of the human body into four stages, then to understand the movement of human body in the process of full-scale frontal impact. (iii) analyzing the force, the seat belt load on the seat sliding rail in two conditions, (1)conventional installation position and (2)new installation position of seat buckle, then discussing the significance of the new way hi light-weight design of the seat sliding rail.

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In the clinic, High Intensity Focused Ultrasound (HIFU) is used to non-invasive treatments for cancers. However, it is not easy to rapidly monitor temperature elevations which reach higher than 60℃ and may cause undesirable thermal injuries. On the other hand, hyperthermia treatment is based on the clinical fact that cancer cells are more weaker than healthy cells hi the temperature range of 42-43℃. In this study, we propose a new type of transducer for hyperthermia treatments with focused ultrasound heating energy to expand the heating area. First, we presented a new type of transducer model for computer simulations. Next, we calculated pressure distributions using a Finite-Difference Time-Domain (FDTD) method with the proposed transducer model. From these results, it was found that the proposed transducer was useful for hyperthermia treatments.

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We proposed the developed simulator system for an effective hyperthermia treatment with needle applicators in a virtual reality (VR). Medical doctors used needle applicators to heat brain tumors, but this method has some problems. As needle applicators have a small heating area, it is not easy to precisely put a needle into a target point for medical doctors. So, a VR simulator system for effective hyperthermia treatments is required in the clinic. In this paper, first, we proposed the developed simulator system in VR for effective hyperthermia treatments with needle applicators. Second, we performed to put the needle applicator into the agar phantom model in VR using the developed simulator. From these results, it was found that the developed simulator system is useful for performing effective hyperthermia treatments.

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In this study, we analyzed the burden of each muscle for the simple motion around the knee joint. This analysis method was used the angular momentum of each muscle and the driving power around the knee joint. We think that the angular momentum represents the intensity of the muscle motion for the driving power around the knee joint. Also, we used Hill type model to muscle model in 3D lower limbs musculoskeletal model. Then, we verified the value and usability of this analysis method by using those analysis result. The value and usability of this method was verified by comparing it with the conventional method. The conventional method was used the driving torque around the knee joint and driving torque of the muscle.

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This paper describes the heating properties of a resonant cavity applicator for heating brain tumors calculated by Finite Element Method (FEM) with blood vessels. The blood flow rate is needed for calculating the temperature distribution during hyperthermia treatments. In previous study, the mean rate of blood flow through human tissue was used hi the conventional method with FEM. However, the accuracy of the calculated temperature distribution around a large blood vessel was not so high. In this study, first, we reconstructed a 3-D anatomical FEM model from 2-D medical images using a 3-D CAD software. Second, we calculated temperature distributions with a 3-D anatomical human head model by solving the bio-heat transfer equation. Furthermore, a comparison of the temperature distributions when considering the blood vessel was discussed. From these results, it was found that temperature estimation during hyperthermia treatments with the cooling effect of blood perfusion is required.

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Simulation of customer behavior in a store was conducted by Cellular Automata. Customer moved around in a store depending on the layout of items, so the layouts of a store have large effect on amount of sales. But in fact, it is difficult for retailers to design the best layout, because there are large amount of items hi a store. In such a case, computer simulation is a powerful tool. We modeled the customer behavior in a store by using Cellular Automata (CA). CA is one of discrete modeling methods. In CA algorithm, local neighbor rules are defined as interaction of elements which compose the phenomena. By using CA, we modeled the interactions of customers hi a store based on the personal space, and also interactions between customers and items. As a result, customers walked around hi a store depending on the layout of goods and the movement of other customers.

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This paper describes the heating properties of agar phantoms mixed with magnetic nanoparticles when using a radio frequency (RF) heating device. We estimated the temperature distribution inside an agar phantom using the finite element method (FEM). Used magnetic nanoparticles were magnetite (Fe_3O_4) and yttrium (Y_3Fe_5O_<12>). Here, first, the electrical properties of agar phantoms mixed with magnetic nanoparticles were presented. Second, the results of heating these agar phantoms obtained by computer simulations and heating experiments were presented. Third, a comparison of these results was discussed. Finally, from these results, the temperature rise of agar phantoms mixed with magnetic nanoparticles was not sufficient for effective hyperthermia treatments.

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A resonant cavity applicator system for brain tumor hyperthermia treatments without contact was presented. To use this heating system in clinics, an accurate 3-D anatomical human model of a patient will be needed. However, this model was reconstructed by tracing outlines of tissues on the MRI and X-ray CT images. Therefore, it was not easy that this model is created correctly. So, the purpose of this study is to extract tissue outlines on the MRI image by using image processing. First, the algorithm of image processing was presented as a flowchart. Second, a comparison of original image and the image that was processed according to flowchart is discussed. From this result, it was confirmed that tissue outlines on MRI images can be extracted by using the proposed image processing.

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This paper describes the experimental results of new heating methods for treating osteoarthritis (OA) inside a knee using a resonant cavity applicator. OA is a common musculoskeletal disorder that causes pain, stiffness, swelling, and loss of function in a joint, hi the previous study, a resonant cavity applicator for thermal therapy of OA was proposed. Experimental results of temperature distributions when using the resonant cavity applicator and using microwave diathermy systems were discussed. However, a knee gap is very close when OA is progressing. It is not easy to heat the affected part of the human knee. For an effective treatment of OA, the deep seated joint cavity region in the human knee must be heated between approximately 36 and 38 ℃. In this study, a more useful method of resonant cavity applicator was developed for OA with keeping stress on leg to widen knee gap. From the results of computer simulations, it was found that the proposed heating method is useful for treating OA inside a knee joint.

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This paper discusses temperature distributions of the improved re-entrant resonant cavity applicator with 3-D FEM abdominal model. We proposed a resonant cavity applicator with metal shields for preventing the edge effect on human abdominal regions. In this paper, first, we reconstructed a 3-D human abdominal model from ultrasonic images. Second, proposed heating method was described. Finally, from the results of specific absorption rate (SAR) distributions and temperature distributions using 3-D FEM, it was shown that the heated area inside a human abdomen could be controlled by changing the electromagnetic field distributions. From these results, it was found that the improved re-entrant resonant cavity applicator was useful for effective hyperthermia treatments.

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Amount of blood vessel diseases has been increasing. Artificial vascular grafts are widely used for transplantation treatment, but they have problems such as clot generation and tissue rejection. Tissue engineering is considered as an excellent method for making artificial vascular grafts. The previous study showed that cyclic mechanical uniaxial stretch caused differentiation of mesenchymal stem cells to smooth muscle cells. The tubular scaffold in this study has elasticity that can withstand 40% of natural blood pressure. This was tested with a created bioreactor for tubular scaffold that is able to control pressure and flow rate with the use of syringe pump. Mesenchymal stem cells were seeded on the scaffolds and cultured for 3days in vitro. The differentiation to smooth muscle cell was confirmed with the use of Real-time PCR. Overall, this scaffold for vascular graft and bioreactor system were shown to be useful in the reconstruction of blood vessels.

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Steam cell-based self-assembled tissue (scSAT) bio-synthesized from synovium-drived mesenchymal stem cell had a great potential for the repair and regeneration of biological soft tissues. However, the mechanical properties of the scSAT were insufficient for clinical application. A candidate solution to the problem is to promote the generation of the extracellular matrix in the scSAT culturing under cyclic strain. In the present study, an elastic tissue culture plate was designed and local strain of the plate was investigated. And mesenchymal stem cells were cultured in the presence of ascorbic acid for 14 days on the elastic plates, then cultured under cyclic 5-6% strain at 1/30 Hz, 7-9% strain at 1/8 Hz or Static culture for 14days. Results revealed that the each area strain of elastic tissue culture plate was homogeneous until 15% strain. And, scSAT cultured under large cyclic strain became thinner and tensile strength was lower. However, tensile strength of scSAT cultured under small strain tended to be higher.

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There is a lack of effective therapies for serious uterus diseases which causes infertility .Such approaches as organ transplants or artificial organs still have safety and technical problems that substitutional bioartificial tissue engineering method is required to regenerate the patients' organs with gestational function. In the conventional uterus tissue engineering researches, it has been reported that seeding mesenchymal stem cells (MSCs) on the scaffold is effective for reconstruction of uterus-like tissues. However, the function of MSCs seeding remains to be seen and the fertility rate of recipients is still low. In this research, we seeded MSCs with autofluorescence of GFP(Green Fluorescent Protein) on decellularized rat uterus tissue so that we could track the behavior of MSCs after transplantation. We then investigated the the tissue 4wk after transplantation and observed a tendency of MSCs' differentiation into smooth muscle cells. It is suggested that this may be caused by tensile strain added to the recellularized tissues aimed at cell inroads into tissues.

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As a therapeutic approach to treat arthropathies such as osteoarthritis (OA), regenerative medicine is a promising method. Tissue engineering of the articular cartilage has been challenged by applying chemical and mechanical stimuli to replicate the in vivo environment, however, there are still many problems to be overcome. To synthesize thick cartilage tissues with adequate mechanical properties, it is crucial to supply nutrients and oxygen to the center of the tissues. In this study, we have developed a new method, the multilayer technique to solve this problem. Compared to conventional techniques that make regenerative tissues via single layers, our proposed technique is able to create thicker tissues with better mechanical properties. Further studies are needed to elucidate the underlying mechanism of this technique.

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The effect of the impeller geometry of the centrifugal blood pump whose impeller rotates with a single-contact pivot bearing on the rotational stability against the hydrodynamic force was investigated. Two types of impeller were compared which were the FR model whose flow path had both front and rear cutouts on the tip, and N model whose flow path was straight. First, the axial thrust and moment was calculated by CFD analysis. Next, the impeller levitation and the impeller tilt were measured experimentally. As a result, the axial thrust of FR model decreased gently as the flow rate increase which was caused by smaller velocity in the top gap that resulted higher pressure in the top gap. The impeller tilts were less than 0.8 ° in both models which was considered to hardly affect the impeller stability.

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Von Willebrand Factor(VWF) plays an important role in regulation of hemostasis and thrombosis formation under high shear rate. We obtained the force curve for the interaction between VWF and GPIbot by atomic force microscope. Some of the force curves showed the multiple peaks, indicating the unfolding of A2 domain of the VWF. The unfolding of VWF may cause the conformational change of VWF.

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Cells respond to not only biochemical signal but also mechanical force, which indicates that cells have some mechanosensors that converts mechanical force into biochemical signal. According to recent reports, one of the candidates of the mechanosensors is focal adhesions that are multi-protein structures that form mechanical links between intracellular cytoskeletons and extracellular matrices. Since the cellular mechanisms of sensing and responding to the mechanical stimulations at focal adhesions have not been clarified yet, we developed a micropillar substrate embedding micron-sized magnetic particles and enabling the micropillars to be cyclically deflected by a time-varied magnetic field. Using the magnetic micropillars, here we applied cyclic strain of some frequencies to osteoblast cells through focal adhesions and tracked cell migration with time-lapse observation to understand how cells sense cyclic strain. As a result, cells change the direction of migration to avoid adhering to micropillars largely deflected at 0.1, 5, and 12.5 Hz.

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When bringing regenerated cartilage into practical use, due to its piece-to-piece property difference, non-invasive evaluation should be developed before implantation. We intended to achieve non-invasive assessment of articular cartilage by applying terahertz technology. The purpose of this research is to clarify the relation between terahertz spectra and cartilage characteristics such as mechanical strength, extracellular matrix structure. In this paper, by applying dielectric analysis to transmission spectra of terahertz wave, we clarified slow relaxation strength of water molecular, which can be corresponding to the amount of free water in cartilage. The amount of free/bound water in cartilage is one of the factors that decide the mechanical properties of cartilage. To verify cartilage characteristics, we performed mechanical test and determined the amount of extracellular matrix. A comparison between slow relaxation strength and cartilage characteristics shows that terahertz technology can be one way of measuring water status and its characteristics.

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This paper describes the relationship between the deformation of cytoskeletal structure and the change in calcium ion concentration as biochemical response in a living cell deformed by a micropipette. Gene transfection of green fluorescent protein enabled visualization of actin cytoskeleton in cells. Local deformation was applied to a cell by a micropipette and the displacement distribution of actin in the whole cell was automatically obtained from the two images of the cell before and after deformation by using KLT method which is one of the feature tracking algorithms. Calcium ion response to the same mechanical stimulation was measured as the spatial and temporal changes of intensity of a fluorescent marker loaded to osteoblasts. As a result, displacement of actin and change in calcium ion concentration were highly correlated and calcium ion response time was delayed with increasing the distance from a stimulation point in a cell.

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Cells are exposed to several kinds of mechanical stimulation (MS). It is known that cells respond to MS, but the signaling mechanism is unclear. In this study, we observed the concentration increase of intracellular Ca2+, which is known as mechanosensitive second messenger, under MS loading condition. We chose poking which pushes cell with a very thin needle and make cell minute deformation. Fluo3-AM was used for imaging the intracellular Ca2+ intensity. We also affected inhibitors to seek which signaling pathway is involved. Cells were observed using EM-CCD camera (HAMAMATSU), and analyzed with Aqua Cosmos (HAMAMATSU). Our results indicated the possibility that G protein is not activated by MS, but by autocrine with secretion of ATP.

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Mechanical stimulation has attracted attention as a stimulus for optimal cultivation of regenerated cartilage, but the signal transduction mechanism has not yet been clarified. Though there are reports that differentiation genes, like Sox9, are up-regulated by loading hydrostatic pressure (HP) to chondrocytes, it is unclear which upstream signals respond to HP. We used ATDC5, chondroprogenitor cells derived from mice, to find HP-sensitive molecules and signaling pathways, and quantify the activation of signaling proteins by western blotting. Under 25 MPa, CREB and ERK1/2 activation were observed after 5 minutes. Loading HP with the addition of galleon, a molecule that inhibits signaling triggered by the βγ subunits of heterotrimeric G proteins, ERK1/2 activation was still observed, showing that ERK activation is independent of those subunits. For further studies, we will use inhibitors for several possible mechanosensitive pathways to explore upstream signal transduction.

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Natural vibration analysis was conducted to reveal the dynamic property of proteins on cell membrane as a mechanical sensor. Living bodies are generally composed of cells and tend to adapt themselves to their surrounding environment. They can get information of the environment and the information is transferred into cells through various kinds of biochemical signals. In this sense, proteins on the membrane of cells may have a function of sensors to get information of surroundings. The proteins have three-dimensional structure, and may be oscillated by external force to living cells. The objective of this study is to analyze the characteristics of membrane protein using Finite Element Method (FEM). In this study, our target membrane protein is "integrin", which is one of the membrane proteins and works for cell adhesion. The structure of integrin was modeled by a lumped mass-spring system and the coordinates of the atoms were determined by the open protein database. The natural frequencies and normal modes of integrin were calculated by the eigenvalue analysis in NASTRAN. The result showed that the integrin had many natural frequencies corresponding to those obtained by infrared spectroscopic analysis, and we revealed natural modes of integrin for each natural frequency in order of MHz, GHz and THz.

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In natural environment such as dams and lakes, density stratification of the water is formed, and this may cause the destruction of water environment. We have developed the application of gas-liquid two-phase jet as the means of destruction and mixing of the density stratification. The purpose of this study is to clarify the mixing optimum by gas-liquid two-phase jet for destruction of density stratification. We conducted the mixing experiment and the experimental parameters were total superficial velocity j_T and volumetric flow ratio of the jet β. The mixing behaviors of density stratification was observed by visualization and density change in the mixing was measured in situ. Based on the visualized and measured results, an evaluation method for the mixing time was developed. We discussed the relation between the parameters and the mixing tune. It clarified that two behaviors were observed and effect of β on the mixing time was varied in eachy j_T.

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As the running speed of Shinkansen increases, the reduction of aerodynamic noise emitted from a pantograph head of Shinkansen becomes more important. This paper describes CFD analysis on the flow control around the pantograph head using synthetic jet actuator (SJA). In this study, spanwise and streamwise orientations of rectangular orifice are analyzed. In the case of streamwise oriented orifice, the cross-sectional area of orifice is also changed under the conditions of constant momentum coefficient or volume flow rate of SJA. The results of CFD analysis indicate that the streamwise oriented orifice is more effective than the spanwise one against the reduction of aeolian tone and that a dominant parameter which determines the reduction of aeolian tone is volume flow rate of SJA.

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This paper aims to investigate the fluid flow in a plane jet issuing into a counter uniform flow using direct numerical simulation of the Navier-Stokes equation. Numerical calculations were conducted for three cases of the velocity ratio of the jet to the counter flow. Cyclic oscillation of the jet reversed by the counter flow was visualized by the streamline and the vorticity contour. It was found that, as the velocity ratio increases, various oscillation modes emerge and the frequency of the fundamental oscillation decreases. An attempt to estimate the position of the instantaneous stagnation-point was made to show the periodic trajectory of the stagnation point while the reversed jet oscillates between the upper and lower sides of the nozzle.

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When a low density fluid, such as helium gas and hot air, is discharged from a round nozzle, side jets may be generated at the initial region of the jet. The side jets are radial ejections of the jet fluid. The side-jet formation is estimated by issuing conditions of the jet flow. The issuing conditions are mainly density ratio between the jet fluid and the ambient fluid, velocity profile and issuing speed at the nozzle outlet. A helium gas jet with side jets was visualized by three-dimensional imaging. From the SD-visualization, several side jets are generated simultaneously, and a vortex ring is distorted by the side-jet formation at the same time. A process of side-jet formation has not been understood even now. In the present work, cross-sectional images of a helium gas jet are visualized by a planar laser Mie scattering and the visualized images are recorded using a high-speed video camera, hi order to investigate the process of side-jet formation.

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Sewage pump is used for the transfer of liquids containing foreign bodies, such as solid and fibrous material. Therefore, high performance hi passing foreign bodies is called for. However, general assessment guidelines have not been established for the performance in passing foreign bodies of the pump. Performance in passing foreign bodies of the pump is evaluated by the size of the passed particle size (minimum particle size of the pump) to the pump bore. In this study, the object is to elucidate foreign bodies' obstruction mechanism and establish the evaluation guidelines for performance in passing foreign bodies of the sewage pump. As a first step, performs a performance test and foreign bodies passing test and visualization experiments with high-speed camera in a closed-type centrifugal pump with single-blade, was to investigate the performance hi passing foreign bodies and the behavior of foreign bodies inside the pump.

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Conventional hydraulic power generation has been operated by large-scale equipment used from high to medium head. However, installation sites having adequate head are decreasing. Moreover, large-scale equipment has great influence on environment. Therefore, it is thought that the generation of electrical energy by an ultra-small axial flow hydraulic turbine of the portable type which utilized low head of an existing pipeline or an open channel becomes promising. However, since the ultra-small axial flow hydraulic turbine has the low Reynolds number, the design method has not been established. In this study, as the first step towards establishment of the design method of an ultra-small axial flow hydraulic turbine, the ultra-small axial flow hydraulic turbine was designed based on the design method of the conventional axial flow hydraulic turbine, and the performance and internal flow were clarified by the numerical analysis.

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In order to clarify the mechanism of the instability phenomenon in an abnormal operation of a pump turbine, the experiment of a pump-turbine was performed. The pressure at inlet and outlet are measured for the various flow rates and rotating speeds. "S-shape curve" was observed in the turbine characteristic curve. The experimental result shows that as the flow rate increases, the torque increases. "S-shape curve" was observed hi a vicinity of the runaway condition. "S-shape curve" in the pump turbine without the guide vane is more clearly observed than that with the guide vane. "S-shape curve" occurs when the increase ratio of the loss is larger than the decrease ratio of the torque.

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The flow in a pump sump is a very complicated one, which has three dimensional flow patterns, deformed free surface, and many unsteady vortices. As the model testing has a problem of similarity, CFD simulation method attracts attention in these days. In this study, a model case flow in the pump sump with simplified shape is simulated numerically. The flow is simulated as three-dimensional with free surface. Using k-epsilon model and LES model, the result is compared each other and also compared with an experiment. The LES result shows more similar flow to the experiment, but the continuous air-entraining vortex cannot be reproduced by simulation. To identify the sump vortex, the swirl function and helicity are better than the vorticity.

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The two fans were designed with the span height of 7mm and 35mm to investigate the influence of the span height on the unsteady flow in a sirocco fan without a casing. The radial velocity oscillations were measured by hot wire probes, and the oscillating frequency and the phase delay of the radial velocity oscillation were obtained by using a fast fourier transform (FFT) analysis. The 3 or 4 peaks were observed in the experiment and the numerical calculation. The experimental result shows that the oscillating frequency and the number of rotating cells in the sirocco fan with the span height of 7mm are larger than those with the span height of 35mm. The rotating vortices caused by the backflow were found in the numerical results.

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Porous aerostatic bearing has high stiffness and load capacity. The present study experimentally investigates the vibration of a porous aerostatic bearing. A laser sensor was used for measuring the displacement of the porous aerostatic bearing. The flow through the porous aerostatic bearing was induced by a centrifugal blower. The volume flow rate was measured by a flow meter. The displacement and the volume flow meter were transferred to a personal computer. The experimental result shows that the displacement of the porous aerostatic bearing is increased with the increase of the volume flow rate. By using FFT, we confirmed that the oscillating frequency is decreased with the increase of the volume flow rate.

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The aims of this study are to research the aerodynamic characteristics of a delta wing in low Reynolds number (Re) region for development Micro Air Vehicle (MAV), and to investigate the effect of leading edge flap (LEF). We evaluated the aerodynamic characteristics of 0.4m span, NACA0012, 70° delta wing at Re = 1.9x10^5 by fluid force measurement using six component force load cells. Further flow velocity distributions around the flow field of this wing were calculated by two component PIV analysis. The relation between the aerodynamic characteristics and the behavior of the leading edge vortices varying with LEF is considered in detail.

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WIG(Wing In Ground effect)can be improve their coefficient of lift by PAR(Power Augmented Ram), that blow air into lower side of a blade in order to increase a pressure in that space. To make their relation clear, we have evaluated such aerodynamic characteristics making some experiments and simulating by computation fluid dynamics. The wind tunnel we have used in the experiments is 600mm in width, and 600mm in height. It is capable of moving air at speeds up to about 20m/s. We cut a lower part of NACA6409 in order to raise a rate of increase in a coefficient of lift compared to it without modification. Aerodynamics characteristics of a WIG is effected by ground when h/c is 0.1 or less.

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In the flow of a transonic compressor, shock waves occur around blades and cause instabilities. The present research investigates the instabilities caused by the shock waves. Four blades were designed with changing the blade leading edge in order to investigate the effect of the blade geometry on the two-dimensional supersonic flow of the blade row. The numerical calculation were carried out for various pressure ratios and circumferential speed ratios. The location of the shock wave in the blade passage are determined by the pressure ratio. The blade without the camber angle can obtain the high pressure ratio, but cannot operate in the wide-range condition. Compared to the original blade, the blade with the thin leading edge can operate in the higher mass flow rate.

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