A processing technology has been developed which uses the Wonder Process Craft (WPC) treatment method to apply a high-purity powder of the solid lubricant molybdenum disulfide (MoS_2) to the sliding surface of the piston skirt with a jet of compressed air. As the powder strikes the surface thermal penetration and diffusion occurs, enabling the formation of a MoS_2 layer in the uppermost layers of the skirt, including the surface. The use of this technology in the manufacture of a 1.3-liter automotive engine has reduced motoring friction under partial load 4-5%, and effect lasting for the life of the engine. In this process only air and powdered MoS_2 are discharged, and the powder is recyclable. No waste treatment is necessary because no waste products are produced, making this technology perfectly adapted to contemporary environmental demands. Pistons treated with this technology are called 'MoS_2 shot-treated pistons' and have been used in mass production vehicles since June 2001.

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The boiler, which applies a pre-mixed combustion method, has a strong tendency with the extremely loud combustion noise. The noise depends on the geometric structure of boiler system. The aim of the study is to clarify the characteristic of such noise and reduce it. In this paper, the combustion noise caused by the combustion-driven oscillation is replaced with the noise caused by the self-exited oscillation. This kind of oscillating system is called "Rijke tube", and composed of the electrically heated. Applying the slit type muffler in self-exited oscillation system, it is proposed a method of noise reduction with the muffler by absorbing the sound energy as the result of resonance.

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In many cases of fan noise, discrete-frequency noise (DFN), which is usually caused by rotor-stator interaction, is observed. Hence, DFN is realized as one of the main target of fan noise reduction. For such a discrete component of noise, a slit--an expansion chamber with very short axial length in a duct--may be effective as a resonator muffler. Since the slit is easy to be attached to actual machinery for its compactness, some results of its performance on an actual fan have already been obtained by the authors. As one of them, in the case of the wind tunnel in our laboratory, which has a considerably large open end, multiple components of DFN radiated from its inlet were observed. In this report, in order to reduce these components simultaneously, multiple slits--each of them is expected to have a resonant frequency coincides with each DFN--was used as located side by side on the inlet of the wind tunnel. As a result of the measurement of noise, the effectiveness of them was confirmed.

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The aeroacoustic performance of perforated tube was experimentally investigated. The effect of perforated angle that was the angle between the perforation axis and the tube axis was investigated as well as the effect of porosity. Sound pressure level and jet thrust for noise-reducing devices have been measured and compared with each other. A perforated tube with forward slanted perforation exerted favorable performance. This type of forward slanted perforation was suffered by another discrete noise at low jet pressure ratio. A devised oblique type of perforated tube reduced the noise level effectively and efficiently.

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Sound power is a useful quantity for rank ordering noise radiated from different machines or machine components. For a complicated vibrating structure. it is difficult to isolate the sound power of specific area from the total sound power with a two-microphone intensity probe or in a reverberant chamber. To facilitate this type of measurement. a new type of intensity probe that measures sound intensity directly on a vibrating surface has been developed. In this paper, the surface intensity probe and the two-microphone intensity probe are used to measure the intensity field of a Gas Heat Pump air-conditioner in order to quantify the sound power radiated from each of its walls and components. It is observed that most of sound power from GHP is radiated from a base plate, an exhaust noise and an intake noise in the 160Hz and 630Hz, 1/3 octave band, which is the most significant frequency bands in the sound pressure spectrum at evaluation point.

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While many works to reduce a broadband noise from wind turbine wings had been carried out, noise source distribution over the wing tip region is not clear due to a lack of technique precisely demonstrate source distribution. By use of the line and cross microphone array systems positioned proximity to the test wing, broadband noise sources are possible to be evaluated precisely. Acoustic tests of the newly developed wing were conducted using the microphone array. This study reports test results associated with broadband noise sources of the wing whose tip turned out to be a strong noise source of a high frequency range.

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Source location technique belongs to noise reduction techniques if it brings about precise information on noise characteristics such as source position, frequency band, magnitude, etc., and helps to decide appropriate countermeasure. This paper describes an experiment of a two-dimensionally distributed microphone array that distinguishes concerning sound source from others in mean flow of a wind tunnel. A small jet engine installed on a half fuselage model was employed as sound source and operated in a low-speed wind tunnel of National Aerospace Laboratory. A panel with as many as 64 microphones was fabricated and settled below the jet engine. As results of multi-channel measurement and frequency-domain analysis, both jet noise source and fan noise source around the nacelle could be detected with high signal noise ratio.

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Recently, it is found that a pressure wave is generated when a high-speed train passes through a structure like an overbridge as well as when it moves into a tunnel. In this study, an axisymmetric flow field where a train passes through an overbridge like structure is numerically investigated. Computational result shows that pressure waves are generated when the nose and the tail of a train passes through an overbridge, and that resonance occurs inside an overbridge. The effect of the geometry of an overbridge on the pressure wave is also studied.

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Existence of Mach cone and helical vortical structure in the helical oscillation mode of underexpanded circular jet was confirmed by using schlieren instantaneous photographs and drawings of envelopes of the Mach cones by the superposition of spherical sound waves radiated from two moving sound sources about the jet axis at a supersonic speed. The enveloes of a Mach cone are observed as a V-shaped pattern composed of a pair of clear fine lines starting from a prominent point, which rotates about the jet axis. The helical vortical structure is observed as bright pattern of the gathering of the tiny specks around the jet. It always apperars to overlap on the envelopes of the moving Mach cones.

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A high velocity flow in a muffler induces secondary flow noises. The flow induced noise in a simple cavity type muffler with pulsating flow was studied experimentally, for simulating the automobile exhaust flow noise. The main sound source in a wide frequency range is thought pressure fluctuations on the wall that caused by the collision of the flow to the wall. In order to clarify the relation between pressure fluctuations and the pulsating flow, the phase difference of the flow in the cavity was obtained using the cross-correlation function. A time-frequency analysis was conducted considering the relation between the flow induced noise and the pressure fluctuation on the cavity inner the wall.

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The sound source term of Ribner's equation was discussed as a detection method of the sound source. The experiments were carried out for a separated airflow, which was generated from a sharp edged flat plate set in a wall jet. The fluctuating static-pressure was measured by the pressure probe, and the second time derivative of the pressure, a sound source term of Ribner's equation, was calcuated. Simultaneously sound pressure was also measured by a microphone outside of the flow. The results suggest that the fluctuation of the sound source term at its maximum intensity station is closely related to the sound pressure fluctuation rather than the fluctuating static-pressure.

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To clarify the mechanism of noise generation from an low pressure axial flow fan, time fluctuating velocity was measured around the rotor blade, especially near the blade tip, by using a hot-wire sensor from a relative flame of reference fixed to the rotor blade. Two sensors were used to obtain the cross-correlation between velocity fluctuations at the reference point and other deferent locations. The results are summarized as follows. If the flow rate was low and the tip leakage flow became to attach to the following blade, the sound pressure level increased. From the data of the cross-correlation of velocity fluctuation the leakage fluid flew downstream spirally, in which a discrete frequency velocity component with low frequency was predominant. It is possibly considered to be the cause of the noise generation of low frequency band.

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Unsteady three-dimensional Navier-Stokes CFD analysis has been performed to predict a fan noise source and to investigate noise source characteristics. Unsteady loading distribution on the stator surface predicted by CFD was compared with the results predicted by two-dimensional and three-dimensional linear theory. We can find that it is important to take into account a three-dimensional effect to predict unsteady loading. Acoustic power levels were calculated from predicted unsteady loading, and compared with experimental data. Noise level based on CFD analysis agreed with experimental data better than that based on three-dimensional linear theory. It is clear that CFD analysis has an advantage in noise source prediction. A mechanism of generating noise source distribution was investigate, and some parts of its mechanism come to be clear.

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An inclined angle dependency of aerodynamic sound generated from an inclined circular cylinder with endlpates is related to aspect ratio, A, that is the ratio of a distance between endplates to the circular cylinder diameter. For analyzing the dependency in detail, we derive correlation lengths from the surface pressure fluctuation and the velocity fluctuation in wake, respectively. As a results, when the inclined angle change from 0 degree to 20 degrees, the correlation length get small at A-10. On the other hand, in the case of A=30,the correlation length get long. So, we visualize the flow around the inclined circular cylinder in order to analyze those phenomena by the numerical simulation and the hydrogen bubble method.

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Flow-induced in-line oscillation of a circular cylinder has been experimentally studied by free oscillation tests in a water tunnel. The 2-dimensional cylinder and the cantilevered cylinder models were supported elastically by plate springs so as to oscillate only in the in-line direction. An end-plate was fitted to the free end of the cantilevered cylinder to examine the influence of end-effects on the flow. Two hot-film probes were set near the cylinder to investigate vortices of near wake. The response characteristics of cylinder show only one excitation region over a wide velocity range. The response characteristics of cylinder with end-plate show two excitation regions near half of the resonance velocity, since the two dimensionality of the flow around the tip of the cylinder is enhanced by the end plate.

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Flow visualization around a cylinder with cruciform cross-section and measurements of fluid forces acting on it were conducted in a water tunnel to investigate their characteristics. The visualized results indicate that flow around a cylinder with cruciform cross-section is classified into two patterns. One is perfectly separated flow, and the other is reattached flow. Perfectly separated flow is observed on the condition of small angle of incidence, and reattached flow is observed on the condition of large angle of incidence. The critical angle of incidence for the flow pattern transition is about 7.5∿15 degree. The steady lift coefficient is negative in any angle of incidence for the flow pattern transition is about 7.5∿15 degree. The steady lift coefficient is negative in any angle of incidence. At the critical angle of incidence, the steady drag coefficient has its minimum value while the Strouhal number and the absolute value of the steady lift coefficient attain to their maximum. The characteristic of flow around a cruciform cylinder and its fluid forces is similar to those of square prism.

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Aerodynamic properties of square prism with respect to various angles of attack were predicted utilizing computational fluid dynamics in which LES turbulence model was employed. The results met well with experiments in time average aerodynamics properties, drag force coefficients, lift force coefficients, and surface pressure coefficients for the cases examined here. In conclusion, this numerical approach successfully predicts mean aerodynamic properties of square prism.

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Flow-induced oscillation tests with a splitter plate in the wake were performed to estimate the range of the wake that affects the oscillation of cylinder. The test results show that the wake down to L/D∿2.6(L : distance between the cylinder and the plate, D : cylinder diameter) affects the averaged amplitude of the inline oscillation at the 2nd unstable region. The wake affected the relationship between the phases of the in-line displacement and the force induced by vortices.

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It is known that a large cross-flow oscillation called the galloping is generated for a rectangular cylinder in uniform flow, in addition to the Karman vortex excitation. However, for practial machines and structures it is rather rare that the motion is the pure cross-flow oscillation, since other oscillation modes such as attack-angle fluctuation or in-line oscillation can be superimposed depending on the supporting structure. In this study, the cross-flow oscillation of a rectangular cylinder supported by a plate-spring system is investigated using a wind tunnel for the purpose of clarifying the effect of attack angle fluctuation on the excitation. The oscillation behaviors of the rectangular cylinder are greatly different depending on the supporting structures, i.e., the pure cross-flow oscillation, the cross-flow oscillation with an in-phase attack angle oscillation and that with an anti-phase attack angle oscillation. The cause of these different oscillation behaviors is the fluctuation of lift due to the attack angle fluctuation superimposed on the cross-flow oscillation.

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Karman vortex excitation can be suppressed by setting a rectangular cylinder in the wake. However, one kind of the longitudinal vortices, Trailing vortex or Necklace vortex, sheds periodically near cruciform two cylinders arrangement in a certain conditions about free stream velocity, gap between the cylinders and rectangular cylinder width. The longitudinal vortex induce stronger vortex excitation compared with Karman vortex excitation. The influence of these parameters on Karman vortex excitation and longitudinal vortex excitation was clarified by wind tunnel experiment. The flow condition that neither Karman vortex excitation nor the longitudinal vortex excitation did not happen was found by this research.

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In the present paper the attention is focused on the vortex shedding from the tube banks with closely mounted serrated fin. The tube banks were installed rigidly in the test section of the wind tunnel. We measured the spectrum and the gap velocity in the simulated tube banks which has same pitch ratio as that of a boiler heat exchanger. We found two types of vortex shedding with different Strouhal number of 0.36 and 0.19 in the case of Reynolds number R_e, based on equivalent diameter and gap velocity, between 1.9×(10)^4 and 5.1×(10)^5. Strouhal numbers S_t were calculated by using the measured values of vortex frequency, gap velocity and the equivalent diameter. the vortex shedding of S_t=0.36 mainly formed within the fin-tube banks and the other vortex of S_t=0.19 was in the wake of the fin-tube banks and the other vortex of S_t=0.19 was in the wake of the fin-tube banks. Strouhal number of vortex within the fin-tube banks changes from 0.36 to 0.3 between R_e=7.0×(10)^4 and 0.9×(10)^5. The applicability of the equivalent diameter obtained by a single circular cylinder with serrated fin to the fin-tube banks was examined. Strouhal number 0.3 agreed well with Strouhal number 0.3 obtained from Fitz-hugh's map for tube banks without fin and other Strouhal number of 0.19 is similar to vortex shedding from a circular cylinder.

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Experiments were conducted to determine the flow-induced vibration response of a model heat exchanger tube bundle subjected to a cross-flow of refrigerent 11 (R-11). The tube bundle consisted of a normal square array of 12 tubes with a pitch over diameter ration of 1.485. Of particular interest in this report was the effect of vapour bubbles in the flow on vortex shedding. It was found that the introduction of a small amount bubbles in the flow disrupted the vortex shedding and thereby caused a significant reduction in streamwise vibration amplitude.

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In this paper, Fluid Elastic Vibration Analsys is performed by the hybrid method using both the Computational Fluid Dynamics (CFD) and the analytical solution. Many CFD simulation results are reported, but CFD simulation takes so much time and machine power. To clear up these problems, we have calculated the fluid force coefficient by CFD simulation instead of experiment. And we purpose the evaluation method for the critical velocity of a fluid elastic vibration.

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As for the heat exchange machine related to energy in thermal power plants, nuclear power plants and so on, the structures with gaps are adopted due to avoiding the heat expansion damage at supports of tubes in which a fluid pass through as a heat exchange medium. Flow-induced vibrations of heat exchanger tubes are recognized as a serious problem that can lead to tube damage through fretting wear. This paper presents numerical simulation of cantilever beam concerning the vibration behavior with the collision when the fluid excitation acts on the beam and the fretting wear due to contact at supports. Then, we consider vibration behavior including the chaotic phenomenon, and the fretting wear volume.

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In this paper, new evaluation method for estimating the damping of U-bend tube used in steam generators colliding with a support plate is proposed. First, we performed experimental modal analysis and obtained natural frequencies, modes and damping without collision by hammering test and then employed FEM taking account of the collision force. In modeling the characteristics of the collision force, we applied Bijlaard's model for the spring constant and assumed hysteresis. Comparison between calculated and experimental results is made which shows good agreement.

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Many researchers investigated vibrations of straight pipes conveying fluid from the viewpoint of nonlinear dynamics. However, there were almost no theoretical studies of nonlinear vibrations of curved pipes and the concrete experiments which used the simple models. The main purpose of this paper is to investigate theoretically and experimentally in-plane vibration of a curved pipe, which is excited by the pulsating component of an internal flow. The experiment is conducted with the silicon rubber pipe conveying water. The spatial displacements of the flexible pipe are measured by the image-processing system that can perform measurements of the marker in three-dimensional space, based on images from two CCD cameras.

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It has been known that the buckling behaviors which occur at the lower part of tank depend on the ratio of hoop stress due to internal static liquid pressure to yield strength. The AIJ guideline for structural design of fluid storage tanks has considered this characteristics. We noticed dynamic effects of the internal liquid pressure on buckling behavior under seismic loading and performed static and dynamic experiments using thin-walled cylindrical tanks. We verified the effects of dynamic liquid pressure on the buckling behavior.

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This paper describes the vibration characteristics of the damper element composed of two annular magnets and magnetic fluid. The experimental system is composed of the vibration-testing system, the three-dimensional high-speed motion analysis system, and the optical displacement detector system. The experiments are made on vertical vibration of the element composed of magnets and kerosine-based magnetic fluid, and of the element composed of only magnets as a magnetic damper. It is found that the element of two annular magnets adsorbed magnetic fluid is effective in the high frequency region. The effect of excitation amplitude on the output response is also revealed in detail.

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In this paper, the mechanism and stabilization of the dynamic behavior of gas-lubricated bearing are considered. The pressure distribution which is generated in compressible fluid at the gap of bearing is caluculated. The equation of motion is derived using the fluid force acting on journal which is caluculated from the pressure distribution. Based on the derived equation, the numerical simulation of the dynamic behavior of the journal is performed and the stability of the behavior of the journal is investigated. Finally parameter studies are shown.

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A self-excited vibration mechanism of leakage-flow-induced vibration is clarified analytically when a wall of one-dimensional tapered leakage passage can vibrate in single-degree-of-freedom translational mode. Added damping force is composed of the element of squeeze effect and that of resistance change. The added damping element of resistance change can become negative. The sign of the element is decided by the location of the first order moments of inertia force and that of the change of flow resistance. In the case of divergent passage, the latter location is in the front side from the former location, and inertia force is dominant at near exit. In this case, negative added damping could occur.

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It is known that flutter of a traveling sheet may occur during its manufacturing process under the influence of leakage flow between the traveling sheet and a guide. In order to avoid the quality defectiveness like wrinkle due to the unsteady phenomenon happening on the sheet, a nonlinear stability analysis of sheet subjected to a leakage flow are performed to study the behavior of sheet in this paper. Concretely, sheet is described as a model consisting of mass less beam elements, springs and discrete mass particles, in which the mass of each particle and spring coefficients are calculated based on the beam model. During the formulation of fluid dynamic forces, nonlinear terms are taken into account for simulation of large-amplitude vibration of sheet, showing the appearance of limit cycle vibration in high flow velocity.

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Cornering stiffness is usually treated as an equivalent term which presents characteristics of tire-suspension-steering system in developing the lateral force at a given tire slip angle. However, influence of suspension and steering characteristics on the value of cornering stiffness and vehicle dynamics characteristics are not separately considered and analyzed. Therefore, the relation of each suspension, steering and tire with vehicle dynamics characteristics is not obviously known. An analytical compliance model in suspension and steering system is proposed here by considering a component of single A-arm, tie rod, kingpin and steering column. And relation of it with cornering stiffness and vehicle dynamics characteristics based on bicycle model are theoretically derived in this paper.

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The steering type of a mechanical guidance system has been used for Automated Guideway Transit (AGT) system in Japan. Receutly, the single-axle bogie system has developed for aGT vehicle and applied to Yurikamome 7200 series. This paper describes dynamic characteristic of AGT vehicle with single-axle bogie system and steering system. By using 13 degree-of-freedom dynamic models, a computer simulation about earthquake is carried out. The result obtained from the computer simulation show that steering system cause increase in lateral acceleration and single-axle bogie system cause increase in guide-wheel force.

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Dynamics of a moving body restrained on a 3-D trajectory considering resistance to forward motion is investigated. The equation of motion of the moving body is derived by using differential algebraic equations (DAE) method. By using this equation, the time history simulation analysis is performed. Also, the kinematics and vibratical experiment have been performed using the actual roller coaster in site. The accelerations in simulation are compared to those in experiment. Both show a good coincidence qualitatively.

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This paper presents the study on the stability of compact bicycle. Recently the bicycles become being focused on transportation tool to solve environmental problem and traffic congestions in cities. In particularly the role of compact bicycles and folding bikes becomes important so that inter modal connection between bicycles and other public transportations for convenient and flexible traffic. However the compact bicycles are less stable than normal bicycles. In this study, the equations of motion of bicycle are led from Newton-Euler law.

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In Japanese situation as the higher aging society, old couples help their self-supporting life each other, for example elder lady pushes the wheelchair giving elder gentleman a ride. For the elder people whose motor function has been dropped, the power assist system of electric wheelchair, which has a extremely higher or lower auxiliary power than their motor function, should not only be comfortable at all but also very dangerous. Therefore, it is very effective to analyze the motor function of human as a prime motor in the human-wheelchair system, we consider. After we made a treadmill on trial basis which has the function of virtual wheelchair, the characteristics on the pushing task has been investigated by mainly measuring the power applied to a wheelchair by human in walking.

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Electric wheelchair could be one of the tools in providing mobility of elderly and challenged. Japanese population is rapidly increasing owing to the medical development and the decreasing of the birthrate. The current-products in the market almost all have joysticks as the controller device. However, it is sometimes necessary to practice the operation in order to be able to use an electric wheelchair effectively. In this paper, we propose the new type of controller device, which has two input units for the turning control and one for the moving control individually. We have evaluated the traveling performance and optimal adjustment of an electric wheelchair. Especially, optimal time constant in case of switching times and adjustment of transducer between Bi-state input to velocity are described.

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Over four million individuals have already tried the Suica system, introduced by the East Japan Railway Company on November 18,2001,and these customers have responded favorably. During the 14 years that this system was in development, researchers focused on high-speed processing as the critical development theme, especially at automatic fare collection gates. That is because customers must have it pass through the automatic fare collection gates smoothly. In this report, I will focus not only on the technical development but also on field tests performed to evaluate the system under conditions similar to actual operations, development of the IC card and its rewriting capabilities for faster processing, and the use of the Touch & Go format, in which the IC and spends more time in the physical range of communication with reader.

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Actual NOx from a freight vehicle whose payload is two tons was measured with simultaneous on-board measurement system for vehicle running conditions and actual exhaust emissions. Amount of NOx exhausted at roadside was specified on test route map and also studied comparing with vehicle motion. It was found that NOx was highly emitted at intersection during lower speed using lower gear position.

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This study aims at a system to measure pressures and temperatures of tires of a car and forces acting between the tires and the road surface, and to transfer the body the measured data by real-time wireless communication. The real-time measurement of the forces between the tires and the road surface will greatly improve performance and reliability of the vehicle dynamics control systems including antilock braking systems, traction control systems, and vehicle stability control systems.

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To improve riding comfort of driver's seat, we have proposed active suspension system for heavy duty truck. In this study, the control mechanism of the active seat suspension was designed for a small vehicle like community car with using coefficient diagram feedback control method. The operability improvement for senior citizen, vibration isolation for baby and riding comfort improvement in the unpaved road can be expected. In order to examine the effectiveness of the system, experiment was performed.

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System identification of a motorcycle by Computer-aided Dynamics Analysis is introduced to design a control system for the attitude stabilization. The identified model can be reduced to the coupled mode system between the roll mode and the front-steer mode. We design the gain-scheduled front-steering control system using the roll angle as the feedback signal, which is according to the varying parameter of mortorcycle velocity. It is verified from simulation results that the motorcycle attitude against disturbance is stabilized by the gain-scheduled controller at the widerange velocity. The effectiveness of the reduced order model used in controller design is shown.

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Passengers' visual fields in high-speed trains are measured in a vacant Shinkansen, with window shades opened. Views of male college students at seats of different arrays are measured using Eye-Mark-Recorder (NAC ENR-8), and recorded parallel to vehicles' 5 d.o.f. floor accelerations and 3 d.o.f. seat accelerations. Eye mark data analysis suggests that gazing objects vary depending on the array of seats. Window view data from window seat with controllable illumination device is conclusively recommended in constructing railway simulator with motion for the purpose of passengers' comfort evaluation.

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The author proposes a new measurement method for the contact force between pantograph and contact wire. This method is based on the inverse identification technique. The position where the contact force is acting varies on the panhead continuously. In such a condition, the measurement precision always becomes worse in the case of inverse identification. Hence, the author proposes an improved method using the pseudo-inverse matrix to take the vibration mode into consideration. To confirm the measurement precision of this method, an excitation test was performed by using a Shinkansen pantograph. The result shows that this method is precise enough even if the position where the contact force is acting changes.

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The self-powered active vibration control is applied to three-degrees-of-freedom suspensions of new transit vehicles. In this system, an electric generator and an actuator are installed in the suspensions. Since the actuator produces the control force utilizing the vibration energy regenerated by the generator, this active control system requires no external energy. To discuss the feasibility, the balance between the regenerated and the consumed energy is estimated. Results of the numerical simulations show that the regenerated energy exceeds the consumed energy. This indicates the proposed system is feasible.

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The foundation technology for embodying an inclination section high-speed escalator was established. The step speed of the escalator in the inclination section is 1.5 times as high as that in the landing section. Therefore, in the inclination section high-speed escalator, the shortening of the movement time consist with the safety in the landing section. In this paper, the result of dynamic analysis simulation that is done as the first step of embodiment is explained. The driving reaction force of steps is affected by the difference of the reversal center position of steps. The reversal center position of steps is optimized.

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Structural optimum design improving both the thermal insulation and the bending stiffness is investigated for the fuel tank of liquefied natural gas vehicle. Assuming that the thermal insulation and the bending stiffness are represented by the heat flow at the boundary and the displacements at the loaded points, respectively, we set modified objective function which consists of normalized heat flow, normalized displacement and penalty function for the volume constraint. Nodal positions on the free boundary are changed for the shape optimization. Use is made of the steepest descent method for the minimization of the objective function. The derivative for the steepest descent is evaluated by means of the difference calculus based on the finite element analysis. The step width for the optimum solution is determined by the golden section method. The validity of the proposed method is proven through two dimensional problems.

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Compliant mechanisms are designed to allow great flexibility in motion in order to reduce the number of mechanical parts needed, and are especially useful for micro-mechanical devices. The problem described here is the design of a two-dimensional liquid nozzle aiming to be used as the injection nozzle of an ink-jet printer. A flexible wall controls the injection, which is assumed to be linearly elastic even with large deformation. The analysis is performed with the spring-segment model. The fluid is assumed to be in ideal flow and analyzed using the finite element method. We first present the formulation of the coupled fluid-structure interaction analysis, and subsequently derive the sensitivity of the outlet width with respect to the design parameters. The relationship between the outlet width and the design parameters is then first-order approximated. The values of the design parameter changes are determined by means of the Moore-Penrose generalized inverse so as to realized the objective value of the outlet width for a certain inlet velocity and pressure. The structural renewal is then iterated to correct the error of the first-order approximation. A Numerical example validating the proposed design methodology is finally presented.

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Fractal branch and bound method has developed by authors for optimization of stacking sequences to maximize buckling load of composite structures. The method demands an approximation of a design space with a response surface of quadratic polynomials for trimming fractal branches of stacking sequences. The approximation of the objective function with quadratic polynomials has been confirmed for the buckling load maximizations using lamination parameters as predictors. Although maximizations of flutter limits of composite panels for supersonic flow has already shown by several researchers, it is not clarified that the design space of the supersonic flutter limit can be approximated with quadratic polynomials. The present paper describes the theoretical background of the fractal branch and bound method, and approximations using quadratic polynomials with lamination parameters as predictors are performed to investigate the effectiveness of the method for the supersonic panel flutter problem with buckling load condition of composite laminates. As a result, the method is successfully applied, and the practical optimal stacking sequence is obtained using modified response surfaces.

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Optimization techniques are useful to determine the unknown parameter according to the evaluations of design. This techniques require to be formulated mathematically. Then the indexes that is difficult to express mathematically, for examples "kansei" are difficult to be included in the optimization problems. In this study, we will propose the algorism based on immune algorithms and try to derive some candidates including solution. immune algorithms are considered as the optimization algorithms. However, the immune algorithms are not fully established becase various algorithms are considered and fully investigated. In this study, from above point of view, we will propose the immune algorithm that treates the "antibody-antigen reaction". Through some numerical examples, we will show the effectivenews of th proposed algorithm.

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