When we tried to solve the equation of motion of Navier-Stokes for incompressible fluid by using finite difference and forward method, it was difficult to get pressure distribution satisfying the equation of continuity. Many solutions tried to satisfy rigidly the equation of continuity. In our solution, the potential flow was chosen as the starting point of calculation, and the pressure was determined so that the divergence of the velocity did not change with time. By using this pressure distribution and the equation of motion of Navier-Stokes, the velocity distribution at the next time step was obtained, but the divergence of the obtained velocity distribution was not necessarily zero. Therefore, even if the divergence of the velocity had a value, some terms with function to converge the value to 0 in several steps were added to the relational expressions. It made possible to easily obtain solutions of flows with boundary separation by using central difference method and simple cube mesh.

Effect of viscosity and surface tension on a levitating droplet over a moving wall are experimentally investigated. We measure levitation duration by changing wall velocity, droplet viscosity and surface tension. We construct a new experimental setup to expand the ranges of experimental condition. By using the new setup, we successfully levitate silicone oil droplets of 1-5 cSt. It is found that droplets levitate with wall velocity which is over a critical wall velocity. The critical wall velocity depends on viscosity of droplets, especially for low viscous regime. The critical wall velocity increases with decrease in droplet viscosity to obtain sufficiently relative wall velocity which is difference between the wall velocity and surface velocity of droplets. Surface tension also affects the critical wall velocity. To levitate high surface tension droplets, high wall velocity is required. We discuss the mechanism with considering area of an air film between the levitating droplet and the wall.

When we tried to measure the wind speed of 10 m / s or less with a Pitot tube in wind tunnels, the dynamic pressure was small and a precise fine pressure gauge was required. The Gettingen manometer could read pressure in unit of 1/10 mmAq, but a more precise micro pressure gauge was needed. So, a micro pressure gauge capable of reading pressure in unit of 1/100 mmAq was developed by using a scale and two cylindrical containers. The one container set on the scale was open to the atmosphere, the other container was a closed. About half of the containers were filled with liquid, and the two containers were connected by a pipe. The measuring pressure was connected to the closed container. When the measuring pressure changed, the liquid moved between the two containers. The changed value of the scale expressed the difference between the measuring pressure and the atmospheric pressure in units of 1/100 mmAq. Multiplying that value by the gravitational acceleration (9.8 m / s²), the pressure value in unit of Pa could be obtained. This relationship did not depend on the kind of liquid.

Drive is the most common ball type of table tennis, but there are a high-bouncing general drive and a low-bouncing drive. In order to clarify the mechanism of the latter drive, we used a table tennis machine and a digital camera (960 frames per second), and examined changes in the angle, rotation number, and velocity speed of the ball before and after the ground contact. As a result, it was found that the ratio of peripheral speed to speed immediately before landing was an important parameter. When its value was smaller than 1, the ball type became a high-bouncing general drive. When its value was larger than 1, the ball type became a low-bouncing and fast drive.

The ventilation effect in the L-shaped structure room was examined by experiment and CFD calculation. It was found that a flow separation occurred at the corner by using steady flow or unsteady flow. The amount of smoke staying in the room could be halved compared to the steady flow by using the unsteady flow. On the other hand, in the case of the unsteady flow, it was found that smoke was expanded in a wide range. So it was necessary to suppress the flow separation at the corner. It was found effective to set a rotating cylinder with a peripheral speed equal to the flow at the corner.

When we ordered an omelet rice at a restaurant, a beautifully molded omelet was on top of the chicken rice. The top of the omelet was opened with a knife, the omelet broke and the egg flew down like wrapping chicken rice. The purpose of this report was to establish methods to promptly provide beautifully molded omelets when restaurants were crowded. And inside of the omelets had to be highly viscous liquid. Therefore, we conducted research on the following three stages. (1) A method of mixing egg yolk and white body without breaking egg shells. (2) A method of keeping a stirring liquid of yolk, white egg and milk in a high viscosity liquid state for a long time. (3) A method of instantly shaping the stirring liquid into the shape of an omelet.

Potato starch powder and aluminum oxide powder was put in a cylindrical container and the container was rotated around the horizontal axis. Inside the container was inserted a device that removed particles adhering to the wall surface, and it rotated at the same rotation speed as the container, but it was braked for a short time at a frequency of once per revolution. Thereby, the two kinds of powder were sufficiently stirred. By means of image analysis, the average value of the center-to-center distances from the nearest particles to each particle was determined. The center-to-center distance when the same number of particles were arranged as in the checkerboard was calculated. The ratio of these two distances was used as an index of stirring state. On the other hand, the value of index of stirring state when particles were randomly distributed was clarified. The ratio of these two indexes of stirring state represented whether the stirring state had reached the ideal state. It was confirmed that an ideal stirring state was obtained by the stirring method described above.

The purpose of this study is to reveal the characteristics of air-refrigerant two-phase flow, such as frictional pressure drop, void fraction, and so on. The characteristics of slug flow in small diameter pipes have been experimentally investigated by using air and refrigerant (HFE-71IPA) as the test fluids. The refrigerant is a highly insulated liquid. Therefore, a measuring method with high voltage supply applicable to the highly insulated liquid has been developed in order to measure the instantaneous void fraction distribution at the cross-section of the small diameter pipe. The some experiments on instantaneous cross-sectional void fraction distribution in air-HFE-71IPA two phase flow were conducted by using wire-mesh sensor with high voltage. These experimental results were compared with that of water.

The effect of cylindrical wing with longitudinal grooves and streamwise grooves to the performance of the magnus windmill is clarified by using different surface shape of rotating cylinder. The rotation number of windmill was measured using a wind tunnel at wind speed of 8~20 m/s. A cylinder rotation is 400~1600 rpm. As a result, it was revealed that a longitudinal groove cylinder has a higher rotation number of windmill than streamwise groove cylinder.

In a tube-type gas burner, which is commonly used in a baking process, the pressure in the burner tube decreases by friction loss, but the outflow from the nozzle along the burner tube decelerates the flow in the tube and thus increases the pressure. The pressure distribution along the tube depends on the combination of these two opposite effects, and the resulting pressure sometimes gives the non-uniform flow from the nozzle, which causes uneven flame along the burner. In this study, the flow inside the buner is theoretically modeled. The goverinig equations are the conservation of mass and energy in the burner tube, and the outflow from the nozzle is calculated with the loss coefficient of the nozzle. The result of the theoretical model shows that the non-uniformity in the nozzle flow depends mostly on the tube length and the loss coefficients. The result of the model agrees with experimental and computational results.

A tube-type filter, commonly used in such as a filtration tank, is a circular filter with an inner tube. The filtrated fluid goes through the inner tube and accelerates as it flows downstream, since the filtrated fluid cumulates along the tube. Thus, the pressure inside the inner tube decreases both by the friction loss and by the flow acceleration. This pressure drop results in the non-uniformity in the permeation velocity in the filter and therefore degrades the efficiency of the filter. In this study, the flow through a tube-type filter is theoretically modeled. The goverinig equations are the conservation of mass and energy in the filter, and the permeation velocity is calculated with the loss coefficient of the filter. The result of the theoretical model shows that the non-uniformity in the permeation velocity and agrees with experimental and computational results.

To investigate the flow structure of the jet issuing from the pentagonal duct with and without the synthetic jet, the flow visualization was carried out. And the velocity measurements of the jet flow were performed by using the PIV method. The jet diffusion was investigated by analyzing the velocity distributions. In order to excite the share layer of the jet, the synthetic jet was spouted from the actuator set on the outside of a vertex of the duct exit at 0 or 45 degree angle with respect to flow direction. As a result, it has been found that the jet diffusion adding the synthetic jet in jet middle-plane is promoted.

This paper presents experiments of the aerodynamic vibration of the multi-connected structures excited by air flow. In this study, the vibration characteristics and the unstable conditions of the self-excited vibration are examined through experiments. The motion of the multi-connected structures is investigated by measuring vibration displacement. In addition, the unsteady fluid force acting on the multi-connected structures (lateral surface) is investigated by measuring unsteady pressure. The local work done by the unsteady fluid force is also clarified. Lastly, the instability mechanism of the self-excited vibration is discussed based on experimental results.

In order to improve product efficiency in the industrial field, it is important to know the flow of the cooling fluid inside the product. In the case of a motor, in order to make compact and lightweight, efficient cooling of the motor must be performed. However, it is difficult to see the flow of the motor. In this study, in-house code written by fortran language is used to visualize the flow in the motor. In this paper, calculations were made using the calculated shape of the concentric double cylinder simulating the actual machine. In addition, a solid assuming the core of the actual machine was inserted in the double cylinder. At that time, simulation of cooling was performed under the condition that the same rotation as the actual operating situation was added, and how each core was cooled was investigated. As a result, it was found that each core was not evenly cooled. Therefore, as future tasks, if the number of cores increases, we will consider ways to efficiently cool each core.

Experimental investigations have been carried out on natural convection around heated vertical plates in which heated plates and adiabatic plates are alternately placed on the same vertical plane. The test fluid was water at room temperature. The heated plates were heated with uniform heat fluxes. The lengths of heated vertical plate, L, were 10 and 15 mm, and the lengths of adiabatic plate, D, were changed as D = 5-50 mm. The flows over the plates and the surface temperatures of the heated plates were visualized with dye and liquid crystal thermometry, respectively. The results show that the flows over the heated vertical plates remain laminar. The local heat transfer coefficients were also measured. The non-dimensional heat transfer correlation on the average Nusselt numbers of the heated vertical plates were proposed using Nu_D (= h_m D/λ) and RaD^* (= gβqwD⁴/αλν).

In 1997, Since Kyoto Protocol was adopted, developed countries in the world started regulate the emission of Greenhouse Gas. In 1999, the goal of fuel consumption was set in Japan. In addition, in recent years in japan, about 20 percent of the Greenhouse Gas emissions are transportation centered on automobiles. Among them, since the car air conditioner operates using the engine power, fuel consumption of about 9 percent on average per year is carried out. So, from the viewpoint of protecting the global environment, inner heat exchanger which is part of the car air conditioner is demanded high efficiency. In order to realize this, in our university laboratory, we are studying about rib which is laid on the wall of heat exchanger for the purpose of promotion of stirring action of inner flow and increase of the heating area. Since the difference of structure of rib cause the change of flow structure in the inner tube, it is important to compare the flow structure and consider the most appropriate structure of rib. As the way to do it, numerical analysis is effective because it is possible to evaluate the performance at a low cost. So in this study, we conducted fluid analysis in the single tube which has rib structure and compared thermal efficiency.

A Very High Temperature Reactor (VHTR) is a next generation nuclear reactor system. From a view point of safety characteristic, a passive cooling system should be designed for the VHTR as a best way of a reactor vessel cooling system (VCS). Thus, a gas cooling system with natural circulation is considered as a candidate for the VCS of the VHTR. The objective of this study is to investigate not only heat transfer and fluid flow characteristics of natural convection but also effectiveness of thermal radiation in a one side heated vertical rectangular channel. It is also to evaluate an amount of transferred heat from heated side wall in order to apply to the passive cooling system of the VHTR-VCS. The final goal of this study is to develop a numerical model which simulated the passive VCS for the VHTR such as the 300MWe gas turbine high temperature reactor (Gas Turbine High Temperature Reactor 300 for Cogeneration, GTHTR300C). This paper describes the heat transfer and fluid flow characteristics from the results obtained by the experiment and numerical analysis in the one side heated vertical rectangular channel. From the numerical results, it was found that it is important to obtain the amount of heat removed by the other walls of rectangular channel.

The heat exchanger with the micro tube group is performed heat exchange by flowing air orthogonally to the micro tube group. In the conventional heat transfer analysis, since the wall thickness of the tube is very thin, the analysis has been carried out by applying isothermal conditions to the side of the tube. However, due to the recent digitization of processing technology, the wall thickness of these tubes is increasing. In this study, Heat transfer analysis of the micro tube group with different wall thickness is performed by changing Reynolds number between solid and fluid, and calculated Temperature distributions in the axial direction inside the tube and Heat flow rate in each tube row.

The problem of heat transfer has both practical and technical interest due to the increasing of heat flux density in microelectronic device. It is important to increase the cooling efficiency and suppress the pressure drop. The objective of the present paper is to propose the actuator control for the suppression of the pressure drop and the enhancement of the heat transfer in laminar regime. As a first step of the present study, the mini-channel with the height of 2.2 mm was fabricated, a vibration plate were developed using a piezo-electric element as a diving source. The temperature of the heated wall under a thermal condition of constant heat flux was measured by high-speed infrared thermograph. The heat transfer was enhanced by the periodic disturbance induced by using the vibration plate. Also the heat transfer enhancement depended on the vibrate frequency, and this frequency of the experiment results almost corresponded to that calculated from the instability analysis.

Plastic thin film is manufactured by drying process where hot air jet is imposed on liquid thin layer. In the process, complicated unsteady phenomena take place, in which convection is driven in the liquid layer by shear stress caused by the air jet and the evaporation occurs at the same time. To understand the process, we did the experiment where PVA (polyvinyl-alcohol) solution was coated on a glass plate and air jet was given for drying the liquid. We did measurement of fluid velocity by visualizing the surface flow of the liquid film, measurement of changing evaporation rate of water, and numerical analysis of the liquid flow. In this paper we report the fluid flow analysis considering the viscosity increase by the evaporation, and investigation about the evaporation rate of water from the liquid to the air.

Application of a regenerative cooling system using hydrocarbon fuel is being studied for reuse type space transport system devised by Japan Aerospace Exploration Agency (JAXA) as a thermal protection method for engine and fuselage surface. To realize the system, numerical analysis technology to estimate thermal cracking characteristics of hydrocarbon fuel is required. In this study, the thermal cracking experiment result of n-octane and the two-dimensional axi-symmetric simulation with thermal cracking result were compared and the validity was evaluated. CRUCH CFD was used for the fluid solver and KUCRS was used for creating the reaction model. This study demonstrated that the simulation roughly reproduced experimental results. However, compared with the experimental results, the simulation results show that the chemical heat sink to conversion rate is small. It is thought that this is mainly due to the fact that reaction products are different due to pyrolytic deposits by coking in experiments.

This investigation reports that the atomization process of Water/Biofuel Emulsion under the electrostatic energy. Biofuel is expected as carbon neutral fuel and contained the water remained in the production phase. From this point of view, making the biodiesel as emulsion can contain the large electric conductivity and be used in the electric applications. In this paper, Biofuel/Water emulsion was tested with the electrostatic energy and discussing in several different electrode distances to figure out the electrospray characteristic. As the result, the field intensity affects the spray modes of Biofuel/Water emulsion and the atomized particles were observed and discussed from the images under microphotograph to understand the electrostatic atomization characteristics.

Lithium-ion batteries (LiB) installed in electric vehicles have advantages such as large energy density and being environmentally friendly. However, it is said that the danger of ignition and explosion occurs due to rapid temperature rise by causing thermal runaway. Therefore, it is necessary to improve the thermal management technology for the LiB. In this study, simulation of simultaneous short circuit of two LiB cells was carried out using numerical model of a cooling system using phase change material (PCM) and heat pipes (HP), assuming simultaneous short circuit of multiple LiB cells. In addition, the contribution to cooling performance was investigated by using several phase change materials with different melting points, and the results are reported.

Mobile devices are becoming more functional, thinner and having waterproof function. Therefore, heat is easily stored inside a mobile device. As a solution to the problem, heat conduction sheet was developed, but its optimum setup is not sure. In this situation, a simple analysis model had been proposed for heat conduction sheet and its numerical prediction was verified with experiments only in case of the outside sheet model. However, the heat conduction sheet becomes installed inside of late. In this report, heat transfer effect was compared between outside and inside sheets using the simple analysis model, and an experiment with inside was conducted.

In recent years, data centers (DC) have become increasingly important. Accordingly, highly efficient and reliable operation and management of DCs have been required. The conventional layout design of racks and ICT equipment in a server room considers the current space and current capacity of power and cooling status, but it does not take into account the temperature or energy performance after environmental changes such as rack removals or additions. On the other hand, for temperature management in the server room, the DC users usually requires DC operator to comply with a service level agreement (SLA) that stipulates that the rack intake temperature is to be kept below a certain level. However, it is not possible to know temperature after environmental changes. To address this problem, we have constructed some models to predict rack intake air temperatures in a server room by using information of ICT equipment, electric power equipment, and air conditioning equipment. In this paper, we propose a method of predicting the temperature after environment changes by using machine learning are developed, and the results of verification and effectiveness in the verification room are reported.

Carbon fiber is almost impossible to be burned out by even high temperature burnt gas because of extremely high melting point of carbon fiber and a low oxygen concentration in burnt gases. In this study, first, oxygen nozzle of 10 mm x 30 mm exit size, which equipped fuel (propane) pipe of inner diameter of 0.8 mm for a pilot ignition flame, has been introduced to observe the in-oxygen-combustion behaiviors of test pieces of (i) CFRP slender plate (2 mm wide and 1 mm thickness), (ii)slender plate of CFRP-P (Plastic removed CFRP), "G"FCRs("Graphite" Fine Cylindrical Rod) of diameters of 0.38 mm, 0.55 mm and 0.72 mm. In order to obtain the fundamental data for analysis of CFRP combustion processes, the flow pattern of combustion gas around "G"FCR and the light emission of "G"FCR surface were also observed. SEM observations on tips of "G"FCR and CFRP revealed that the burnt CFRP tip was extreamely sharpened by the oxygen combustion to have a nanometer-order curvature radius.

As a new small-size energy source using a liquid hydrocarbon fuel, micro-combustor with liquid fuel is expected to be put into practical use. Many issues, however, still remain for practical application of micro-combustor. One of them is the difficulties in complete vaporization of liquid fuel and flame stabilization inside a limited space. This study employed the electrospray, studied a suitable hydrocarbon blended fuel to micro-combustor from viewpoints of calorific value, electrical conductivity, etc., and investigated the limit of flame stabilization inside the combustor.

We present experimental investigation of parametric instability in downward propagating C₂H₄/O₂/CO₂ flames. Parametric instability of fundamental mode is observed for S_L: 27.5 ~ 30 cm/s. Parametric instability of first harmonic transitioning to fundamental mode is observed for S_L: 32.5 ~ 42.5 cm/s. Parametric instability of second harmonic transitioning to first harmonic and further to fundamental mode is observed for S_L: 45 ~ 50 cm/s. Higher modes of parametric instability transitioned successively to lower modes as the flame propagated downward. The transition of parametric instability to lower modes can be understood by studying theoretical variation of acoustic structure functions along the length of tube for velocity coupling. Flame position of maximum pressure amplitude under each acoustic mode corresponds to maximum of acoustic structure functions for corresponding mode. Wavenumber of corrugated flame structure in parametric instability depends on acoustic mode generated in tube. Higher mode instability makes larger wavenumber compared to lower mode instability.

In recent years, ethanol has attracted attention as an environmentally friendly substitute fuel because of exhaustion of petroleum resources and environmental issues. Previous studies have revealed that it is possible to perform continuous combustion at a wide range of air ratio for low concentration ethanol, by atomizing and burning an ethanol water solution using a swirl burner. It is also clear that low NO_x can be realized even in experiments in which the fuel flow rate is constant regardless of the fuel concentration. In this study, we examined the influence of the supplied fuel flow rate on exhaust gas temperature and exhaust components (especially CO emissions) of the swirl burner. The exhaust gas temperature is measured in combustion chamber and exhaust pipe by using K type thermocouples. The main conclusions are as follows:1) Under the high air ratio condition, the flame length decreases with increasing the fuel flow rate. 2) Under the condition of E60 at λ=1, CO emissions decrease as the fuel flow rate increases. 3) CO emissions increase with increasing the fuel flow rate at any ethanol concentration. 4) Exhaust gas temperature monotonically decreases with increasing the air ratios at any fuel flow rate.

PM aggregation technique by water vapor addition and condensation was attempted. PM exhausted from a benzene laminar diffusion flame was used as test sample. Particle diameter (D_PM) distributions of original PM and water condensed PM were measured by a Low Pressure Impactor. Mass concentration of water condensed PM at D_PM < 160 nm (corresponding to peak diameter of original PM diameter) was lower than that of original PM. Then, mass concentration of water condensed PM at D_PM > 160nm was higher than that of original PM. Therefore, it was considered that PM aggregation promoted by water vapor addition and condensation.

In a gasoline direct injection (GDI) engine, fuel is injected into a cylinder directly to achieve higher thermal efficiency. However, in GDI engine, some of the fuel injected into engine cylinder impinges on the piston top and cylinder wall, and fuel film results from it on the wall. When the flame arrives the fuel liquid film, liquid film is vaporized and vaporized fuel is burned. Its combustion state looks like a sooty diffusion flame of liquid pool combustion. Then, soot formation from shallow dish pool combustion flame under high ambient temperature condition is investigated as the fundamental study of fuel film combustion in GDI engine. In this study, Measurement method of PM exhausted from unsteady combustion of liquid pool flame was developed. And relationships among flame length, fuel consumption rate, and PM exhaust rate were discussed. As the results, much of PM was exhausted at the final stage of the pool combustion.

The sugar mill in Tanegashima burns sugarcane bagasse as a fuel of in-house power and heat source and ineluctably generates a massive amount of unused heat around 200°C. On the other hand, many factories in Tanegashima uses oil-fired boilers to generate a process steam up to 120°C all year around. In order to resolve this spatial and seasonal mismatch between heat source and demand, we propose the application of thermochemical energy storage and transport system using zeolite steam adsorption and desorption cycle to the sugar mill and the factories. In this study, a conceptual design of a heat storage unit namely “Heat Charger” was proposed employing counter-flow type moving bed reactor. The heat charger was designed by our in-house quasi-2D simulation code which was validated with the result of preliminary heat charging test. The energy storage and transport system including the heat charger was evaluated from economical aspect. The electricity cost of blower power due to a large pressure loss in the moving bed accounted for most of the OPEX and a flattened cylindrical reactor with 3.5 m in diameter and 0.4 m in height was designed to desorb 1520 kg/h zeolite at the sugar mill.

With the impacts of weather disasters on agriculture and the decrease of agricultural population, a plant factory, which is a closed growing system which enables a farmer to achieve constant production of vegetables all year around, offers a mean for secure efficient agricultural production. However it needs a large amount of initial investment and a large energy consumption. Furthermore the Japanese energy industry has relied on large scale power plants where electricity comes from burning fossil fuel which lead to CO2 and other greenhouse gas emissions. Therefore, results presented in this paper focus on planning an independent energy system, which uses hydrogen as an energy strange mediums, and which takes into account environmental and economic evaluation on plant factory.

The photocatalyst absorbs ultraviolet rays to generate active oxygen and decompose organic matter. In this paper, focusing on titanium oxide with high active capacity, we developed photocatalytic plate for water treatment. The titanium oxide film formed on the plate surface has adhesive strength that does not peel off even at a water pressure of 2.6 times at the time of the river flooding. The plate was irradiated with sunlight and water treatment performance was evaluated by Chemical Oxygen Demand(COD). As a result, it was confirmed that 125L/m² of water treatment was possible in 12 hours under sunlight ultraviolet irradiation. From this, it was found that the plate produced has water treatment performance equivalent to the pretreatment with chlorine required for making tap water in the water purification plant.

To utilize waste glass fiber-reinforced plastic (GFRP) and to adsorb dye wastewater in dyeing factories, we aimed to develop a dyes adsorption material that could purify polluted water. This is achieved by exploiting the porous nature of ceramics produced by mixing crushed waste GFRP with clay before firing the resultant mixture. To evaluate the dyes adsorption ability of the ceramics, adsorption tests of methylene blue (MB) aqueous solution on several kinds of ceramics made using GFRP containing 40% glass fiber, Clay and POM resin were carried out. Then, the mechanism of MB absorption on the ceramics was examined based on ceramic specific surface area, pore distribution and carbon content. The ceramics produced by mixing 60%GFRP with clay before reduction firing at 800°C exhibited a high MB absorption ability. It is believed that a part of plastic included in GFRP was changed to carbide during firing, and the carbide had a large specific surface. It is expected that ceramics from waste GFRP and clay could be used for dye adsorption materials.

To recycle silica byproducts and to moderate the heat-island phenomenon, a porous ceramic was prepared by mixing waste silica powder with clay and then firing the resultant mixture. The high water-absorption capacity of the ceramic was used to produce a greening material: a moss-covered porous ceramic. To examine the suppression ability of the temperature increase caused by solar-radiant heat on the moss-covered ceramic as well as to clarify the influence of water absorption in the sample on the temperature increase suppression effect, the surface temperature change of a moss-covered sample during solar radiant heat reception and the amount of water evaporated from the sample were measured simultaneously. Furthermore, to verify whether the moss-covered ceramic can reduce the indoor temperature, the heat flux acting between the sample rear surface and the rooftop floor of a testing structure was measured. The experimental results confirmed that the moss-covered and ceramic samples that could absorb sufficient water could suppress the temperature increase caused by solar radiant heat, and the moss-covered sample could suppress it for a longer time when compared to the ceramic sample.

Sufficient stabilization effect of the implemented PID controller was confirmed by a comparison with the robust control system. The implemented PID controller was automatically designed on-line by the self-identification function of the non-contact conveyance system. The conveyance system is constructed of the three-axis (XYZ-orthogonal axis) stage and the electromagnet, both of them were manufactured for this study. The three-axis are all controlled by the three AC-servo motors respectively and precisely by using the new type of PLC (Programmable Logic Controller) named Sysmac NJ, manufactured by Omron Corporation. The electromagnet with an embedded displacement sensor is attached to the three-axis stage to be able to move just above a levitation object. The Z-axis (vertical axis) moves automatically to execute the self-identification of the parameters which are necessary to design the PID controller for the magnetic levitation control system. On the other hand, the robust controller was designed off-line by using a new model named FNFR (Finite Number Frequency Response). The robust controller was also implemented in the non-contact conveyance system to compare and make sure the stability of the PID control system. An experimental result shows the effectiveness of the proposed design method.

In this paper, we present a new design of robust observer for nonlinear strict feedback systems. Many controllers that have been proposed in control engineering require full information of states. However, we may not be able to measure full states because of cost or physical constraints. Therefore, many researchers proposed various observers for estimating sates. Luenberger-type observer is the most popular observer in control engineering. However, Luenberger-type observer may not work well when it is applied to systems with uncertainties. Therefore, the robustness of observers is an important issue. In this research, we propose a robust observer called Integral sliding mode observer (ISMO) by introducing some kind of auxiliary system to Luenberger-type observer. Even if the system has uncertainties, the proposed observer guarantees the stability of estimation errors if the uncertainties satisfies the conditions for generating sliding mode. We simulated a single pendulum and van der Pol oscillator. The simulation results show the robustness of the proposed observer.

In this paper, we propose a system identification method for a multi-copter. In the system identification, we must determine a lot of parameters with trial-and-error adjustments. Thus, results of the system identification depend on not only characteristics of the multi-computer but also designer's experience. To solve this problem, our proposed method employs a support vector machine, which is a machine learning algorithm. With the proposed method, we can obtain robust parameters against the plant perturbations from a separation hyperplane for positive and negative of identification results. Simulation results show effectiveness of the proposed method.

In this paper, we improve trajectory tracking performance of 2DOF (2 degree of freedom) control system in multi-copters. The multi-copter is expected to be used in various fields. In order to expand usages of the multi-copter, we have to control position of the multi-copter with high accuracy. Therefore, in this study, we propose a design method for the trajectory tracking control in multi-copter by using the RBode Plot. In the propose method, we employ wavelet transformation in order to obtain a time-frequency analysis of the tracking error in the 2DOF system. Simulation results are shown to demonstrate the proposed approach.

In the design stage of turbomachinery, it is necessary to analyze rotordynamic (RD) fluid force fast and accurately. Conventionally, it was difficult to analyze RD coefficients in the case with large static eccentricity as it required huge number of analytical equations to be solved. In this paper, the extended bulk flow analysis is improved to investigate RD coefficients in such case with large static eccentricity (up to about 0.8 times clearance) with much smaller number of analytical equations. To this end, the order of assumed solution is changed depending on the maginitude of static eccentricity, only the terms affecting RD coefficients are considered in the assumed solution properly, and analysis is conducted by using harmonic balance method. As a result, the number of analytical equations required for the analysis of RD coefficients in the case with large static eccentricity is greatly reduced. Furthermore, the validity of proposed anaytical method is confirmed by comparing its results with the results of previous report.