Nanomaterials such as carbon nanotubes, semiconductor nanowires, and metallic nanowires have the electronic and mechanical properties useful to nanotechnological applications. Metallic nanowires have drawn much attention of researchers since a single-atom chain of gold atoms at a nanocontact between a STM probe tip and a metal surface was observed. They are promisingly applicable to wiring in nanocircuits. Understanding their dynamic characteristics is essential to realization of such an application. In this molecular-dynamics study, deformation of gold nanowires under enforced elongation is addressed. Three kinds of model nanowires are prepared. The modified embedded-atom method (MEAM) potential is employed for calculating the interation between gold atoms. Before elongation, a model nanowire is equilibrated at a specified temperature. Then, the atoms at one end of the nanowire are moved translationally in the direction along the nanowire axis.

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Recently miniaturization of electronic equipment such as mobile phone or personal computer requires high density packages such as BGA or CSP. It is necessary for us to confirm the solder joint reliability of the electronic packages because the solder joint must be under higher stress and higher temperature. FEM simulation is useful method for such evaluation. Authovs investigate A influence assessment of PCB thickness for the pbfree solder joint reliability of electronic packages.

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In recent years, a lot of studies have been done on data collection of mechanical device, especially large skill measuring system through the Internet. However, due to the different output format of conventional mechanical devices, building of a common database becomes difficult, thus affects the sharing of data. In this paper, we discuss how XML data format is introduced to the input/output interface parts of measuring system; and the development of a measuring system, which utilizes RELAX(Regular Language description for XML) schema to ease the formation of database. By doing the above mentioned, sharing of data and the extension of database can be made easy.

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As recent trend has shown that consumers prefer buying products that reflect their own personality and characteristic, it is almost certain that individual-oriented product is gaining weight day by day. Parallel with the popularization of placing order via the Internet, this research combines the usage of Internet-based product ordering system with the concept of individual-oriented product, thus developed a system so called Internet-based Consumer-oriented Product Ordering System. The system allows the user to choose the specifications of a product from a wide range of choices and at the same time, shows the feasibility of manufacturing the product. As there are restrictions for specification combinations due to manufacturing constraints, the initial setting of system by manufacturer must be made easy in spite of the large quantity of specifications. In order to do, this paper propose a hierarchically division of specification and method of setting restriction for specification combinations. On the other hand, this paper also proposes a specification selection support method by using data mining methods, as the level of specification selection required by each individual may be different.

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In this paper, we describe the composition of metadata, which is required for structuring of description knowledge by using the ontology technology of Semantic Web. In this research, machine design knowledge is chosen as web resource and the structured metadata is written in ontology language, OWL (Web Ontology Language). By the ontology, which can automatically calculates the hierarchical relationship and the adjustment during the metadata definition relation between metadata, data sharing and advance searching become easy in the web environment, thus increase the efficiency of mechanical designing processes.

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The importance of simulation of tunnel ventilation in an emergency condition is increasing. To take countermeasures against that situation, we developed an internet-based ventilation simulator for safe tunnel design. This simulator can calculate wind velocity and smoke concentration in a road tunnel with arbitrary size. It can simulate jet fan ventilation system and transverse ventilation system. It calculates unsteady condition so that transitional situations such as fire can be simulated. Users can choose tunnel size parameters, traffic conditions, ventilation systems, and other calculation parameters, through web interfaces. Results of simulations are also provided to users through the internet as raw data and visualized images.

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Fluctuation of blood pulse flow was examined experimentally. Blood flow velocity in a artery was measured by a sensor probe of supersonic reflection measuring system. Measurements were made for sitting, studying and bicycling. Time series of blood flow and time intervals fluctuated for each conditions. The inclination of power spectrum decreased with the increase of moving load, such as sitting and bicycling. Chaotic characteristics were also examined.

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Influence of relative humidity on thermal amenity was experimentally examined. Relative humidity was varied from 30%RH to 90%RH every 10%RH under a constant temperature or 28 degree C. Thermal amenity was estimated by the intensity of brain wave (alpha wave) in adition to sensory test. Thermal amenity of sensory test and the intensity of alpha wave decreased with the increase of relative humidity. Temperature distribution of human body increased with the increase of relative humidity. Transpiration cooling of skin was thought to be restricted by surrounding humid air.

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To which unpleasant factors, such as road surface vibration and maintenance of a taking-a-seat posture, always exist in a crew member during a run. A crew member's each part of a human body is influenced (increase of the stiffness of the shoulders and sleepiness, lumbago, etc.), and these unpleasant factors serve as a feeling of fatigue moreover. Considered that the amount of accumulation of a feeling of fatigue increases with progress of time, in this research, the experiment which checks change of the feeling of fatigue when carrying out posture maintenance for 5 consecutive (with no break) hours on the conditions which imitated the road surface input paying attention to the time of 5 hours required for the run between Tokyo and Osaka was conducted.

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This paper describes the evaluation of the visibility, when people watch a vehicles' meter. There are many aspects in vehicles' meters as the element of interior now. Some vehicles' meter has so many decorations that it may not have the required basic function. Therefore we focused on which function is more important for the visibility. It has assumed that driver's behavior is to recognize the meter as the picture first and to review from his memory when people perceive the meter. We have evaluated the visibility of vehicles' meter elements at first. And we verify that by the experiments. And we found the significant difference at difference of the scale.

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In this paper, evaluation of work procedures from the aspect of ergonomics is conducted for the purposes of skill acquisition and reduction of workload. For our research target of casting process in real casting plant, workload is analyzed through motion study and OWAS (Ovako Working Posture Analysis System), which is a standard index for workload analysis, and the result is then applied into a psychology model, called Lens model. From the above, difference in operation motion between skilled and un-skilled worker can be considered.

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Meat slicing machines with rotating cutter are widely used in meat industry. At present, it is called that this type of machine has some dangerous and healthy problems based on the slicing mechanism. In order to solve these problems, a new meat slicing principle is proposed in this study. That is, a new slicing mechanism with a wire is proposed, and slicing characteristics with a wire is evaluated experimentally. As the test results, it is clarified that slicing mechanism with wire can be applied to actual process, and then, a possibility to develop safe and healthy slicing machines can be made clear.

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This study provides useful information to design proper supersonic convergent-divergent nozzle (C-D nozzle) of rectangular cross-section for cooling air grinding. Experimental analysis verifies that behavior of the air flow through the C-D nozzle is similar to the isentropic flow of the perfect gas if the frictional exclusion caused near the inner wall is allowed for the convergent part to minimize reduction of the isentropic efficiency. The potential core length L_<PC> is measured out under the correct expansion condition. Each L_<PC> is correlated with air flow parameters, stagnation pressure p_0, the flow rate Q*, and geometric parameters of the convergent configuration. A procedure, which is capable of determining the nozzle configuration, is proposed based on the isentropic assumption and experimental relationship between L_<PC> and Q*.

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Fine particle of the Aluminum alloy have been obtain by mechanical milling (MM) treatment. To obtain information about powdering process of the ductile Aluminum alloy during MM treatment, hardness and Transmission microscopic observation were performed. The hardness increased linearly with increasing MM process. Moreover, It was clear that the dislocation density increased and more tangled during MM process.

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The effect of stress inducted martensitic transformation on the machinabilities of austenitic stainless steels (SUS301, SUS304 and SUS316) were investigated. The yield stresses of all steels were almost the same and the work hardening were remarkable in the order of SUS301, SUS304, SUS316. The scatters and mean values of hardness distribution in tensile deformation were large in the order of SUS301, SUS304, SUS316. And tend similar to the work hardening. Moreover, these tendencies were observed in the roughness of machined surface. The machinabilities in turning of austenitic stainless steels were discussed by the relationship of the hardness and the stress inducted martensitic transformation.

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In order to make clear the influence of titanium content of machinability and mechanical properties in Cr-Mo steels, lathe machining and hardness test were examined in water cooled and annealed Cr-Mo steels contained titanium 0.00mass% to 0.93mass% at dry atmosphere. Machining conditions are feed rate f=0.1mm/rev, depth of cut a=0.1mm, and cutting speed V=1.2m/s. The surface roughness of all steels were about 3 micron meter, and increasing the titanium content, the surface roughness of water quenched Cr-Mo steels was increased. Moreover, tool wear is related to hardness that independents of contained titanium, increase titanium content steel with increasing the tool wear.

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The aluminum matrix composites reinforced with Al_2O_3 particles were processed and the effect of Al_2O_3 particles on the machinabilities of these composites were investigated. As a result, the measured Vickers hardness values rose remarkably in a critical penetrated depth of indenter. And, the critical penetrated depth increased with increasing particle volume fraction and particle size. The dependence of volume fraction and particle size on the flank wear in turning were remarkable in the depth of cut smaller than the critical depth of Vickers indenter.

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The effect of the cutting fluids on the machinability of Al-Cu-Si alloys which is candidate of the free cutting aluminum alloy without lead have been studied. The turning test was carried out using the cutting tool with the chip breaker. It was found that surface roughness after machining of the alloys became roughened, while the generation of the adhesion on the cutting tool was increased either in the dry or the wet cutting conditions. In the dry cutting, the chip breaking was better in the over-aged alloys where the adhesion was easily generated. On the other hand, the chip breaking in the wet cutting was better in the under-aged alloys where the adhesion was hard to generate. These results can be explained in terms of generation of the adhesion on the cutting tools; in the dry cutting, the chip was greatly bent by the existence of the adhesion on the cutting edge of the cutting tool though, in the wet cutting, the chip breaker acted effectively by the adhesion was not easily generated.

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The performance that was further superior to before is required also about a bolt with the conclusion function that is the composition element as a demand of the safety and reliability over a structure becomes high. Although this report is aimed at development research of the bolt made from a titanium alloy which does not contain an expensive alloy element, it examines the impact strength of bolted joint which has a bolt simple substance and initial tightening force here.

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Friction force acts between the objects which are going to contact mutually and exercise relatively. Although the problem of this friction is very important on engineering, the action resulting from the fricative characteristic and friction is difficult theoretical to treat, dynamic action, and there is little research of the action especially under impact load. This report, in order to investigate the friction action of the object under impact load, experiment equipment is designed, it asks as a friction coefficient of the object to a impact, it compares with the maximum stillness friction coefficient.

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In strength design of bolted joints subject to impact load, tightening was performed initial tightening force of bolted joints in the elastic area, and the additional force by impact load are experimentally considered from the study result. From the viewpoint of guideline for design of bolted joints, the permissible maximum external force should determined, assuming that initial tightening force of bolt lowered by external impact load should be under 10%. And the result clarified that the maximum impact load (external force) would be allowed up to 54 thru 65% of yield point force of bolt.

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To evaluate seismic response of flexible structures including sliding behavior, the friction model in consideration of the switching of static and kinetic friction was introduced into the 3 degrees of freedom system using the unilateral contact model. The sliding behavior of the structures and the work of sliding of simulations with the analysis model are very good agreement with the shaking table experiments in both the timing and the value of the sliding displacement.

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In recent years, as more attention is paid to the global environment safety, it has become important to consider the entire life-cycle of products in their design, The role of fasteners are very important when the machine system is assembled/disassembled. Snap-fits are commonly used today in the manufacturing of plastic parts. In this paper, the optical configuration of the cantilever hook type snap-fit made of polyethylene terephthalate is obtained by experiment. These result can be used enhance the performance of cantilever hook type snap-fit through an improved design.

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Bolted joint is used for construction of many structures. Dynamic characteristics of structures with bolted joint are important for design of structures subjected to dynamic load. In this paper, the effects of diameter of bolts and roughness of contact surface on dynamic characteristics of structure are examined. Using specimens with bolted joint, the damping ratio and the natural frequency are measured. The damping ratio is measured from free vibration and frequency sweep method. The natural frequency is measured from frequency sweep method. It is found that the damping ratio increases with the increase of diameter of bolts and with the decrease of roughness of contact surface. The natural frequency becomes higher when diameter of bolts is larger.

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Vibration of elevators should be reduced for safety of elevator and protection of luggage and passengers even if they are subjected to many kinds of excitations. In this paper, reduction method for vibration of elevator using rubber between roller and its supporter is proposed. From experiment using mockup of elevator, reduction of vibration using the proposed method is observed. The results are demonstrated by analytically using a model.

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The purpose of this work is to identify the characteristics of a nonlinear vibration system subjected to a random input. In a general, a statistical technique of a higher order spectra(HOS) could be used for non-gaussian data analysis. Then, this method was executed for a nonlinear vibration system.

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We have proposed a magnetic levitation control system for thin steel and confirmed the realization by the digital control experiment. However, the case in which only the levitation control is applied for the thin plate, it has no horizontal restraining force in the traveling. Then, the electromagnetic actuators are installed in order to control the horizontal position of the levitated thin steel and the electromagnetic attractive control forces of the actuators are given for the faced two edges of the levitated thin steel from horizontal direction. In this paper, consideration under such condition on the vertical vibration characteristic of the steel plate was carried out. Experiments were performed for a rigid steel beam and a rigid aluminum beam in order to examine the change of the vertical vibration characteristic by the effect of the magnetic field for the plate edge. As a result, it was confirmed that the horizontal magnetic field for the plate edge equivalently affected as a vertical linear spring force.

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In this study, examination on elastic vibration of a thin steel plate under magnetic field by using permanent magnets was carried out. Especially, consideration was performed on the effect of pole and arangemeht of the magnets. Based on the result of the basic study using a single degree of freedom model, examination for a steel plate was performed. The attractive force of the permanent magnets is analyzed by using the finite element method and the elastic vibration of the steel plate was calculated by the finite difference method. To verify usefulness of the permanent magnet system, experiments were performed for an elastic steel beam. As a result, it was confirmed that the permanent magnets could increase the damping factor of elastic vibration of the steel plate.

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Knocking is one phenomenon that can be cited as a factor impeding efforts to improve the efficiency of spark-ignition engines. With the aim of understanding knocking better, light emission spectroscopy was applied in this study to examine preflame reactions that can be observed prior to autoignition. Light emission intensity was measured at wavelengths of 306.4 nm (characteristic spectrum of OH), 329.8 nm (HCO), 395.2 nm (HCHO). As a result, preflame reaction was observed, and the preflame reaction interval of HCHO showed a different tendency to that of HCO.

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The combustion method by premixed charge compression ignition has been investigated as the improvement method of thermal efficiency in internal combustion engine. In this paper, newly developed continuous intake and exhaust variable valve timing mechanism was applied to premixed charge compression ignition engine and it has verified by the cycle simulation about the influence of engine performance by the difference of air fuel ratio and valve timing in part load. Consequently, the possibility of control of EGR, high speed flow in intake valve and temperature in ignition timing have been shown by VVT.

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This paper presents the results of experiments conducted with a 2-cycle engine that was the world's first such engine to comply with the 2000 California emissions regulations for small off-road engine adopted by the U.S. state of California in 2000. This engine is fitted with two scavenging passage that runs around the crankcase and space of between piston and inside of the crankcase before the scavenging port. The aim of this research was to investigate how changes in the quantity of heat transferred to the fresh air as a result of varying the width of the scavenging passage would affect the state of combustion and exhaust gas composition.

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A technique for removing the NOx contained in combustion exhaust gas has been developed by using radicals produced in the mixing arc plasma. By feeding the gas mixture (Ar+H_2),(Ar+NH_3),(Ar+Diesel oil), (N_2+H_2),(N_2+NH_3),(N_2+Diesel oil) into arc plasma torch, hydrogen, ammonia and diesel oil radicals such as NH_2,NH,HC,N,H are produced, and these radicals are mixed in a reactor with the simulated exhaust gas (N_2+NO),(N_2+Air+NO). The NO decreases as a result of the formation of the innocuous products N_2,H_2O and CO_2 when O_2 is not contained in the gas. Under present experimental conditions, the thermal De-NOx process and the oxidation of ammonia, diesel oil are not expected. In the case of the gas (N_2+Air+NO), NOx increases with increasing input power to plasma. The effects of input power, molar ratio NH_3/NO, Diesel oil/NO, and the distance from nozzle exit to exhaust pipe L/d on the NOx removal rate are investigated experimentally.

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In recent years, some reports demonstrated that toxic compounds such as 1.3-butadien, benzene, group of aldehyde, and so on, exist in the exhaust gas from gasoline automobile. Benzene and 1.3-butadien particularly have been proved to be the cancer-causing substance. Even if those unregulated components are relatively quite less in quantity compared with regulated gas components, the effect on human health should not be neglected. Therefore, those pollutants have to be reduced by means of possible emission control technology. Then, we examined the effectiveness of secondary air supply into exhaust port in addition to various catalysts in order to reduce effectively benzene.

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Fuel-rich solid propellants have been studied to use them in hybrid rocket motors by many researchers. However, there remains much to be understood about these propellants. In this study, the combustion characteristics of fuel-rich solid propellants are investigated theoretically and experimentally. A quasi-steady and one dimensional flame model has been developed for solid-propellant combustion. The steady burning rate of fuel-rich solid propellants is analyzed using this simple flame model. In addition, the ignition delay experiments of fuel-rich solid propellants were performed at atmospheric pressure by a high-power infrared lamp. Also, the linear burning rate of these propellants was measured at subatmospheric pressure. As a result, effects of ammonium perchlorate content on the steady-state combustion and the ignition are revealed experimentally.

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The aeroacoustic noise caused by pantographs is one of the dominant noises of high speed trains and a large obstacle for further speed-up for Shinkansen. In particular, panheads have a large influence on the aeroacoustic characteristics of pantograph. In this paper, we treat panheads as a two-dimensional prismatic model. The purpose of this paper is to understand the dipole source distribution around a panhead. First, simulation is executed by using the LES technique to obtain fluctuations of the flow field around the panhead simplified as a two-dimensional model. Then, we evaluate dipole sources by applying the Howe's Vortex Sound theory. As a result, it is proved that the time-dependent vorticity fluctuations produce large sound pressure fluctuation.

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Aerodynamic characteristics of an airship with circular and elliptic hull sections in cross flow were examined experimentally. Size of the airship model with circular section was 1/300 of the Hindenburg and its overall length and the maximum diameters of hull are 0.8m and 0.14m respectively. Length of the elliptical model is same as the circular one and aspect ratio of minor and major axes is 1:1.5. The experiment was carried out changing yaw angle from 0° to 180° and Reynolds numbers. Effects of Reynolds number and the yaw angle on drag, side force and yaw moment for both the models with circular and elliptic sections were made clear.

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In order to investigate the flow phenomenon inside the oil strainer used for filtration of the transmission oil for automobile, the flow velocity measurement and numerical analysis, which used water as operation fluid, were performed. By comparing a measurement result with an analysis result, the validity of the numerical analysis result for inside flow in the strainer was examined. As the result, both agreed well to each other, and the validity of the numerical analysis result for the internal flow in the strainer was confirmed.

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The characteristics of the unsteady forces acting on the body are quite different from the quasi-steady ones. The peaks of the lift force are observed for moving airfoil with high angle of attack. A time dependent flow forces called the dynamic lift have to be taken into account because the moving motion is obviously unsteady. In this study, the wind tunnel tests were conducted using Magnetic Suspension and Balance System (MSBS) to measure the aerodynamic forces. The support interference problem does not exist for MSBS because the support force of the model is generated by the magnetic field and any mechanical support system is not needed. Furthermore, the measurements of the three-dimensional velocity to understand the relation between the dynamic lift and corresponding unsteady flow field are carried out. Lift and Drag forces of the model were measured with MSBS and it is confirmed that the lift and drag forces become larger as the angle of attack increases.

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We have examined the behavior of the particles in a two dimensional system by using the rotary barrel with round section and the particle with round section up to now, for the examination about the factor of the segregation in the barrel which rotates around the horizontal axis. Then, we have demonstrated that the segregation occurred depending on the relation between the diameter and the mass of two kinds of particles. In this study, we have examined the behavior of the particles with square section, which were filled into the rotary barrel with the round section through the experiment and the simulation using Discrete Element Method (DEM). As a result, we don't found the segregation in our experiment and simulation.

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The range-lengthening effects of dimples pitted on a golf ball surface are known as the results of boundary layer control. Our previous paper dealt with the effect of drag reduction through the wind tunnel experiment with model dimpled spheres, made clear the optimizing design conditions, and proposed the concrete procedure to design dimples optimally. The present paper describes the two major effects of dimples on boundary layer structure at a sphere surface. These effects are (I) the reduction of critical Reynolds number and (II) the recovery of drag coefficient in the supercritical. Based on the experimental data in our previous paper, we estimate and discuss both effects in comparison with the trip wire and in aid of the influence of surface roughness on pipe friction coefficient, respectively.

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This paper describes the control of the turbulence intensity in a facility, which is a square channel with air entered passing through turbulence promoters arranged with small circular holes in a grid state on a flat plate. By changing the diameter of the hole and its arrangement, the intensity levels of turbulence were controlled within the range of 15 to 25 percent, which will be used for the investigation of fuel spray characteristics. Almost uniform profiles of mean turbulence intensity and mean velocity in the cross sections were confirmed by the measurements of LDV and PIV. It was also found that the turbulence and velocity profiles in the channel become uniform at short approach distance.

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Separation is mostly an undesirable phenomenon because it entails large energy loss in fluid machinery. The vortex generator jets have proven effective in the control of boundary layer separation. Longitudinal vortices are produced by the interaction between jets and a freestream. The vortex generator jets method is active control of flow separation and can achieve the adaptive control by properly adjusting the jet speed. In the previous study, it concluded that the triangle orifice generates the strong vortices and effective the pressure recovery in the diffuser. In this study, the vertex is changed with respect to the freestream direction for four types of triangle orifice (Model-L, D, U and R). The suppression effect of vortex generator jets on flow separation causes the different tendency when the vertex points to the right hand side (Model-R) with respect to the freestream direction.

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A radial underexpanded jet issuing from a rounded slit nozzle is experimentally and numerically examined. The radial jet is considered to be one of the models of a wall jet formed when an axially-symmetric underexpanded jet impinges on a flat plate. A noise generation from the underexpanded jet is a significant problem because the underexpanded jet is widely used in industries. It is pointed out that disturbances from the wall jet affect feedback mechanism which causes the noise generation. A detailed analysis of the three-dimensional behavior of the wall jet is required to make clear the mechanism of noise generation from the impinging jet. The structure of radial underexpanded jet is partly revealed through the experiment and the calculation.

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A supersonic unsteady jet issuing from a pipe end is numerically and experimentally examined. The flow field is simulated using TVD scheme and visualized by means of a shadowgraph method and a schlieren method. These results are compared to each other. The unsteady jet is considered to be a model of a pulsating jet discharged from an exhaust pipe of a reciprocating combustion engine and a reciprocating compressor. A noise emitted from the exhaust pope system is a significant problem. In order to clarify the mechanism of the noise generation, a complicated behavior of the unsteady jet is analyzed such as a vortex ring generated at the pipe end and a shock embedded in the vortex.

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An underexpanded jet issuing from a circular nozzle is used for many industrial applications such as an assist gas for the laser cutting, a cooling jet for the glass tempering process and so on. The impinging jet on a flat plate can be considered to be a simple model of such flow field. In this paper, the oscillatory behavior of impinging jet is numerically studied by solving three dimensional Euler equations using TVD scheme. As a result, the oscillation of the impinging jet is found to be associated with the spiral motion of the free jet and so, the disturbances around the wall jet propagate in the radial and the circumferential direction simultaneously. Furthermore, an irregular oscillation caused by the behavior of the separation bubble in the jet is also discussed.

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Jet issuing through small holes into a freestream have proven effective in the control of boundary layer separation. Longitudinal (streamwise) vortices are produced by the interaction between the jet and freestream. This technique is known as the vortex generator jets method. In the case of a jet inclined to the wall from which the jet issues, the separation control work better. Although the mechanism for suppressing flow separation using vortex generator jets have been studied by many researchers, the details of near fields of an inclined jet are not cleared yet. In the present study flow visualization technique is applied to know the unsteady feature of near fields of the jet exit. At lower Reynolds number it was found that the separation area does not flow to the downstream, which is different from the past result. Furthermore we found that the separation area moves to the downstream at the Reynolds number higher than that compared with the case of the cylinder wake.

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This paper describes the experimental results about characteristics of rotor under the condition that the rotor sprays liquid from the slit at sidewall. When a hollow rotor is partially filled with liquid, the motion is unstable in some rotational speed range. This phenomenon is due to liquid surface wave occurring in the rotor. In the experiments, unstable vibration occurred in high-speed range as increase of liquid flow rate.

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Many birds increase by flapping the wing and the whole wing is flexibly moved this time. This movement produces a difference in the air resistance. The air is grasped enough, when the wing is moved in the downward direction. The air is released from the clearance of the wing, when the wing is moved upward. It is considered to apply this mechanism to the bird type wing of the wind turbine. In the paper, effects of the angle of medium wings and the top and bottom wings are investigated experimentally. The reduction method of noise and the guideline for lightweight are clarified.

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The aim of this investigation is to clarify self-starting performance of Straight-Winged Vertical-Axis Wind Turbines by using blade element method: Self-starting properties of VAWTs depend on its parking position and numbers of blade. In the case of even number of blades, the rotor torque is decreased by influence of aerodynamic forces of each blade. On the other hand, the rotor torque is increasing at odd numbers of blade. The numerical result shows that the highest performance of self-starting torque is provided with VAWT with three blades.

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The aim of this investigation is to evaluate shear stress distribution of artificial heart. In order to avoid hemolysis, shear velocity measurements are necessary to design artificial hearts. In this paper, we attempted to measure the shear velocity near the casing wall in the artificial heart model by using PIV. High shear velocity regions were observed near the casing wall. Tip clearances are important to design the low shear-stress artificial hearts. Distribution of shear velocity was also measured with discrete vortex method. The result of numerical simulation was good agreement with experimental result. Outbreak frequency of hemolysis is strongly depending on the time-history of received stress. Numerical simulations and PIV measurements are therefore important to estimate hemolysis of artificial heart.

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