The Proceedings of Conference of Kanto Branch
Online ISSN : 2424-2691
ISSN-L : 2424-2691
2018.24
Displaying 1-50 of 209 articles from this issue
  • Shoshi KIMURA, Masashi KUROSE, Akira YAMAUCHI
    Session ID: GS0101
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The purpose of this study is to investigate the effect of Bi addition to Ag-free and low Ag lead-free solder on their mechanical properties. Sn-0.7mass%Cu (SC07) and Bi (1 and 2 mass%) added to their alloys were used in this study. Tensile tests and low cycle fatigue tests for their specimens were carried out at room temperature (25°C) under 1.0× 10-3 and 1.0×10-1 s-1 strain rate. After these tests, microstructures of their specimens were observed by OM and SEM, and their elements were analyzed using EPMA. The strain rate increases with the tensile strength and elongation increase similar to SAC alloys. The addition of Bi into SC07 caused an increase in their tensile strength and fatigue strength. This is because Bi dispersed uniformly in the specimens and also dissolved in the primary Sn as a solid solution. The addition of Bi has effect on fine primary Sn grains.

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  • Takumi OTA, Akira YAMAUCHI
    Session ID: GS0102
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The purpose of this study is to investigate the influence of Sb addition to Lead-free solder alloy. The specimens used on this study were Sn-0.7Cu with and without Sb. Tensile tests for these specimens were carried out at various temperature (25, 80, and 120°C) under 1.0×10-3 /s. The addition of Sb was increased tensile strength for each temperature. This is because Sb was dissolved in the primary Sn as a solid solution. The addition of Sb has a little effect on their elongation. DSC analysis showed that the addition of Sb increases their melting point gradually.

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  • Yoshiyuki MATSUSHIMA, Akira YAMAUCHI
    Session ID: GS0103
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The use of lead-free solder alloy is required by the RoHS directive. Sn-Bi alloy is one of candidate material for low temperature bonding. However, Sn-Bi alloys has low ductility and then improves the brittleness using superplasticity. The purpose of study is to investigate the deformation behavior of Sn-Bi-Cu alloys using inhomogeneous specimens. It is found that cross-section inhomogeneity factor has an influence on strain rate.

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  • Ryoji SAKAI, Akira YAMAUCHI
    Session ID: GS0104
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The purpose of study is to investigate the surface cleanliness of printed circuit board after reflow process. FT-IR measurement for specimens were carried out in this study using comb type printed circuit board and standard SAC305 lead-free solder paste. From the results of FT-IR measurement, it is showed spectrum of adipic acid clearly. There were two characteristic bands at 2973 cm-1, 1694 cm-1 corresponding to O-H, C=O, respectively. However, it is not found the spectra from resin.

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  • Jumpei UMEYAMA, Masashi KUROSE, Akira YAMAUCHI
    Session ID: GS0105
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The purpose of this study is to clarify the conditions of Sn-Bi alloy’s superplasticity. Sn-Bi-Cu and Sn-Bi-Ni alloys were used in this study. Tensile tests of Sn-Bi alloys were carried out at various temperature (25, 60, and 80°C) and under strain rates (from 5.25×10-5 to 5.25×10-2 /s). In both samples, superplasticity was observed at high temperature (more than 60°C) and low strain rates(under 5.25×10-4 /s). Sn-Bi-Ni alloy showed better elongation at high temperature and low strain rates than Sn-Bi-Cu alloy. In addition, strain rate sensitivity ‘m’ value for Sn-Bi-Ni alloys was larger than for Sn-Bi-Cu alloys. From the results of the microstructure observation after superplasticity, it is showed that the primary crystal Sn grains don’t deform along the axial direction.

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  • Kohji SUZUKI, Yuan WANG
    Session ID: GS0106
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In the present study, as a preliminary report of the present authors on “On Additive Manufacturing of Green Composites”, poly(lactic acid), PLA, composites, which is reinforced with one kinds of reinforcing fibers in the form of milled filler, i.e., carbon fibers, was molded by melt mixing and then filament extruding processes to make green composite filaments for 3D printing additive manufacturing purposes. From tensile test results of single monofilaments extruded from a FDM (Fused Deposition Modeling) 3D printer with a nozzle of 1mm diameter, it was found that the milled carbon fibers were able to reinforce PLA, From the scanning electron microscope (SEM) fractography of the fracture surfaces in the present green composites, interface imperfections between PLA matrix and reinforcing fibers except carbon fibers, unevenness of reinforcing fiber distribution as well as existence of resin rich portions in the composites may have affected the present poor results obtained in this preliminary study.

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  • Kohji Suzuki, Morihiro Tsukada, Takeshi Takatoya
    Session ID: GS0107
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Additive manufacturing (AM) or so-called 3D printing may be one of the promising and disruptive technologies in today’s advanced manufacturing industries because of their unique advantages over the conventional subtractive machining, such as design and optimized-shape flexibilities and material-properties controllability. On the other hand, sandwich structures are one of the typical lightweight structural forms in the composite engineering field, and the core layers, which are usually mage from honeycomb and form, have a lot of possibility in terms of structural and functional Designs. Topology optimization based on the Density-type Design variable set on each finite element in the shape Design regions of the parts and components are a powerful and flexible tool to achieve any structural light-weight design. In this study, fused Deposition modeling (FDM) type 3D printers are effectively applied to manufacture topology-optimized light-weight cores in sandwich beams under three-point bending boundary condition. The FDM printers used in this study were MF-1000 (Mutoh Corp.) and Fortus 900mc (stratasys Corp.), the materials used for core 3D printing were poly lactic acid, (PLA) and ULTEMTM9085. For the purpose of validating the present manufacturing process, the actual sandwich beams were tested for three point flexural properties, and compared to FEM numerical analysis. From the results in this study, the present 3D printed sandwich beams had sufficient strength and stiffness under the Design loading amplitude, and was better than those of the sandwich with conventional honeycomb core layer. Furthermore, the usefulness of this method was discussed from the obtained results.

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  • Kyohei SUZUKI, Kohji SUZUKI, Takeshi TAKATOYA
    Session ID: GS0108
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    CFRP is an innovative structural material in the manufacturing industry, which is still gaining worldwide attention.CFRP is a composite material in which carbon fiber is impregnated with resin, and various molding methods exist.CFRP is characterized by a laminated structure by laminating a resin with a thermosetting resin.A CFRP that has advantages of high rigidity, high strength, and light weight has a disadvantage of low vibration damping.By inserting the damping material in the laminated configuration, it is possible to add value that improves vibration damping capacity.By obtaining the physical property values corresponding to the molding method and the laminated construction, it is possible to give the design more width.In this research, the physical property value of CFRP is identified based on the result of the vibration test.The vibration parameter of the vibration test and the FEM actual eigenvalue analysis result are compared in finite element numerical analysis.Based on the two results, the result is identified by using the material property as a variable.Furthermore, we adopt an optimum design for the layer of the damping material of the CFRP laminate by the density method.Prepare two specimens. One is a CFRP laminate. The other is a CFRP laminate with a vibration damping material in between.Physical properties of CFRP are identified with CFRP laminate. The physical property value of the damping material is identified with the CFRP laminated material sandwiching the damping material.The Young's modulus and shear elastic modulus of CFRP were used as variables, and identification was carried out by the primary Newton's method.It was possible to identify suitable physical property values for vibration parameters in the first order mode.We applied this result to the phase optimization by the density method and found a special form.

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  • Kohji SUZUKI, Tatsuya TAKAISHI, Daiki KAGOTANI
    Session ID: GS0109
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    CFRP has a laminated structure not found in general metal materials such as aluminum alloys, and anisotropy due to them. Furthermore, there are various kinds of damage generated, and they can be roughly divided into three types of transverse crack, delamination, fiber breaking, but damage occurs only inside the material in each damage. As a result, there are also injuries that cannot be detected from the outside visually, so it is difficult to evaluate them. In this study, a tensile test was carried out on CFRP cross-ply symmetrically laminated materials of laminated construction in which the thickness was constant and the ratio of the 0 ° layer and the 90 ° layer was changed, observe the occurrence of damage from the measurement of events at the time of damage introduction by AE, furthermore, focusing on transverse cracks which occur as initial damage among various types of damage, the occurrence / progressive behavior of transverse cracking damage due to tensile load was evaluated from the side observation of specimen by digital microscope, the strain energy release rate by the finite element method (FEM) was compared and examined in each laminated structure by using the transverse crack density guided from there. As a result, the tendency of damage occurrence was confirmed by tensile test and AE test, from the crack ingenerate test, the tendency of occurrence and progress of transverse cracking in the layer was found. In the FEM, the strain energy release rate was obtained, and the tendency and change in each laminated structure could be found out.

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  • Kohji SUZUKI, Yousuke KANEKO
    Session ID: GS0111
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    CFRP is superior in specific strength, specific rigidity and lightweight compared to commonly used metallic materials. By using this material it is expected to secure safety and improve fuel economy. The use of CFRP is expected to continue expanding in the future. However, CFRP has a peculiar breaking form such as interlaminar separation, in-layer resin cracking, fiber breakage, and fiber withdrawal. The Strength of CFRP remarkably decreases due to these damage. As a further big problem, it can be said that it is very difficult to visually judge the damage itself. Currently, non-destructive inspection by ultrasonic flaw detection and X-ray CT is used, but the device itself is big and expensive. Therefore, in this study, the impulse hammering excitation test is carried out on the CFRP laminated composite material partially having non-adhering part and vibration characteristic measurement is carried out. From the result obtained by this, we verify whether it can be used as a simple non-destructive inspection.

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  • Takumi OZAWA, Takuo SUZUKI, Mutumi MIYAGAWA, Takanobu TAMIYA
    Session ID: GS0112
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Generally, metallic materials are used as isotropic when designing structures. However, the crystal grains show preferential orientation due to heat treatment and deformation processing. It is conceivable that the influence of the crystal anisotropy on the metallic material can be increased. For example, internal damage occurs in the heat-affected zone of the welded joint. The anisotropy of crystal grains has been pointed out as the cause of this by preceding studies. In this study, stress analyses in the elastic region is carried out based on a model considering individual crystal grain shape, various number of crystal grains and crystal anisotropy orientation by using FEM. Thus, it is the purpose to investigate the influence of anisotropic microstructure on entire mechanical properties of materials. In these analyses method, the average elastic constants and the stress distributions of the entire models are calculated from simplified shape and actual approximated shape grain models. And, the various number of crystal grains are treated in these analyses. The results of this study show that the values of Yong's modulus are nearly constant, when the number of crystal grains are increased. In addition to that, the similar equivalent stress distributions are observed in different crystal grain shapes when the similar crystal anisotropic orientations are treated.

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  • Ryo SASAKI, Kazuhito SHINTANI
    Session ID: GS0113
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Dynamic encapsulation of pyrenes into a single-walled carbon nanotube (SWCNT) is addressed via molecular dynamics (MD) simulation. It is revealed the final structures of encapsulated pyrenes are classified into two categories according to the size of the SWCNT diameter. For the SWCNT diameters less than 1.470 nm, the azimuthal angles of pyrenes during sliding within the SWCNT are almost zero, and they form a stack, whereas for the SWCNT diameters equal to or greater than 1.470 nm, their azimuthal angles during sliding are nonzero, and they form not a stack but a sequence of trimers. The conjugate-gradient (CG) energy minimization confirms the final stacking structures for the SWCNT diameters less than 1.470 nm obtained via MD are energetically favorable ones. A semi-analytical formula expresses well the tilt angles obtained via MD.

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  • Kohei KAWASAKI, Kenji GOMI
    Session ID: GS0114
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    An apparatus for measuring a birefringence distribution of a large area at a high speed is desired. Therefore, the phase-stepping method is suitable for this because there are no moving parts in the equipment. In this research, we aim to develop a calculation procedure to eliminate errors resulting from tolerances of optical elements constituting the apparatus. Measurement of birefringence phase difference was carried out using a device composed of laser, attenuator, polarizer, quarter-wave plate, specimen, analyzer and CCD camera. As a result, the coefficient of variation of the measured birefringence phase difference was as high as 8.64%. The cause is considered to be the effect of tolerance and assembly error of the optical elements constituting the apparatus. We thought that this coefficient of variation can be made smaller by approximating the obtained brightness value to the theoretical value. The obtained brightness value was compared with the theoretical value and error of the birefringence phase difference was investigated. As a result, it was found that error of the birefringence phase difference can be reduced by using the correction function for approximating the obtained brightness value to the theoretical value. It was also found that accurate measurement of birefringence amount of unknown sample is possible by using this correction function and theoretical value.

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  • Jianren FENG, Masahiro KANEKO, Katsuaki KIKAIKOSHIMURA, Masato SAEKI
    Session ID: GS0115
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    This paper presents the study of the motion of a foreign object in a relay numerically and experimentally. In the numerical approach, the motions of the foreign object and the relay electrode are analyzed the discrete element method (DEM) and the finite element method (FEM), respectively. The impulse force which a relay electrode gives to the foreign object is calculated by using the theory of elasticity. The charge simulation method is used for calculating electric field between relay electrodes. In the experimental approach, and the motion of the charged foreign object is tracked with a video camera. The foreign object is beforehand charged using a corona charging device and the electric charge was measured with an electrometer. As a result, the negatively charged foreign object bounds considerably compared with positively one. The adequacy of the analysis method is justified by comparing with the experimental results.

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  • Ryuki TAMURA, Mutsumi MIYAGAWA, Hitoshi NAKAMURA, Jyo SHIMURA
    Session ID: GS0116
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Bending rupture occurs at the base of the pier at the time of an earthquake on rigid structural bridge constructed before the 2004 road bridge specification manual’s addition of earthquake resistant knitting. The shear buckling phenomenon, due to shear deformation, was confirmed in the abdominal plate at the central part of the beam. This made it impossible to absorb earthquake energy in the direction perpendicular to the bridge axis at the time of the earthquake and it became difficult to recover due to the destruction of the base. In recent years, with the improvement of analytical techniques, it has been proposed to reduce low yield / high ductility material to the abdominal plate in the center part of the beam. More techniques for improving earthquake resistance in the direction perpendicular to the bridge axis are also developing. But, if shear buckling occurs in the failsafe portion, the energy absorption performance of the failsafe portion deteriorates, leading to bending failure of the base portion and destruction unexpected. For this reason, seismic retrofitting at the central part of the beam along the road bridge specification book is currently underway. It is believed that by reinforcing the abdominal plate by increasing the number of horizontal stiffeners, more than the vertical stiffening plates, the number of small material pieces is reduced and the workability at the site improves. Therefore, the performance of non-reinforcement, cruciform reinforcement and horizontal reinforcement is carefully examined and qualitative evaluation on shear buckling is carried out.

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  • Taishi CHIYODA, Akitoshi OKAMOTO, Sigeru AOKI, Katumi KURITA, Shigeomi ...
    Session ID: GS0117
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Welding is a joining method utilizing locally given heat. Since heat is locally applied to the member, tensile residual stress is generated in the vicinity of the welded portion and the fatigue strength of the member is lowered. As a method of reducing the residual stress, there are methods such as heat treatment and shot peening, which require special equipment and long process time. Therefore, a method of reducing the tensile residual stress in a short time applying ultrasonic vibration to the welding member while welding has been studied. In this paper, the effect of reduction method of residual stress using ultrasonic vibration on the tensile strength for overlay welding on SUS304 is examined by tensile test and observation of micro structure. In conclusion, welding using ultrasonic vibration does not affect the tensile strength of the base metal.

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  • Chisa TSUYUKI, Akinori YAMANAKA, Yasushi Ogimoto
    Session ID: GS0118
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    We have developed the phase-field model for simulating the general corrosion in an iron immersed in an acid solution. This model was formulated on the basis of the Bockris's iron dissolution mechanism in order to describe the dependence of pH in the solution on the corrosion rate. This study presents the applications of the proposed phase-field model (Bockris-PF model) to the simulations of the pitting corrosion and the intergranular corrosion in the iron electrode. The results showed that the Bockris-PF model enables us to simulate the complex migration of an interface between the electrode and the solution, the ion concentration in the solution and the electrostatic potential during the intergranular corrosion.

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  • Ten-u TSURUTA, Mutsumi MIYAGAWA, Takuo SUZUKI, Yukio MIYASITA
    Session ID: GS0119
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Many bridges were built during the period of high economic growth, and now there are about 700 thousand bridges with bridges over 2 [m] in bridge length. However, about 20% of these have been over 50 years since the installation, aging is becoming serious. In recent years, high load that are not supposed in the design at the time occur in bridges due to increase in traffic volume and large vehicles. Currently, the non-destructive inspection is mainly magnetic particle flaw detection test, ultrasonic test and x-ray transmission test. However, these inspections can be inspected only in a narrow range and difficulties such as requiring skills by inspectors, which takes time and labor for inspection. For this reason, it is necessary to propose a wide and direct and easy to understand inspection method. In this research, we conduct fundamental research on nondestructive inspection which can detect defects existing in a steel bridge with mechanoluminescence materials in a wide area and simply. In this study, a compression test was conducted on a test piece with defects, and it was confirmed that the acquired intensity distribution coincided with the main stress distribution obtained from the analysis by the finite element method.

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  • Tomofumi SHINODA, Satoru TAKAHASHI, Hiroyuki WAKI, Masahiko KATOH
    Session ID: GS0120
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Thermal barrier coatings (TBCs) is an indispensable technology for protecting hot-section components of power generation gas turbines. A TBC is a multilayer structure consisting of a metallic bond-coat (BC) and a ceramic top-coat (TC) on the substrate. For designing an advanced TBC with excellent durability and reliability, it has been required thermal and mechanical properties of TBCs. Especially, the Young's modulus is one of important mechanical properties to evaluate thermal and mechanical stresses. In previous study, a method was newly developed for measuring the Young's modulus of TBC from room temperature up to elevated temperature by the flexural resonance. Using this method, the Young's modulus of TBCs produced by a thermal spraying was measured from room temperature up to 1000°C and the effects of the number of repeated measurements and the holding time at 1000°C on the Young's modulus were investigated in this study. It was found that the Young's modulus of TC increases with increasing the number of repeated measurements and then increases according to the parabolic rule of the holding time at 1000°C. Such changes in the Young's modulus of TC was discussed in relation to the microstructure of TC with the lamellae structure.

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  • (Part 6 Feeding and Evaluation)
    Hiroaki IYI, Ryoichi NAKAYAMA
    Session ID: GS0201
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Aiming at realization of ultra-small desktop injection molding machine for molding small polymer parts (10 mm cube), we changed prototype molding materials from conventional screw type to new disk type. In order to increase the extrusion amount per unit time in the plasticizing process, it is necessary to improve the plasticity by improving the mounting position of the heater, the entry of molding material, the structure of the stator, the heat insulating structure. By operating the molding machine under more optimum conditions, the molding material could be stably heated and plasticized. As a result, we realized desktop type idea for miniaturization (space-saving, energy saving) of injection molding machine.

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  • Kazuya AMANO, Yasutake HARAMIISHI, Shinsaku Hagiwara
    Session ID: GS0203
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Grinding processing is the final finishing of mechanical products and an indispensable step. For complex shapes, polishing is done manually. Among them, it is difficult to polish the inner surface of a small diameter pipe even manually. Therefore, we propose development of wire polishing tool using electrostatic flocking method. In this research it is possible to polish at low cost without requiring special equipment. The tool manufacturing method is shown below. Attach a nylon pile with electrostatic flocking to the epoxy coated wire. A tool was prepared by attaching abrasive grains on a pile using a commercially available adhesive. In this study, polishing was performed by combining rotary motion and vertical motion using a mini-milling machine and a linear actuator. A stainless steel pipe having a length of 30 mm and an inner diameter of 6.0 mm was used as the work. In order to sustain the performance of the tool, the tool was exchanged every 10 minutes, and the polishing was carried out for 180 minutes in total. As a result, roughness improved from initial roughness 3.507 μmRa to 0.696 μmRa after polishing.

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  • Shunya NAGATA, Takeshi TERAJIMA
    Session ID: GS0204
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Development of and the structure analysis for the fibrous metallic glass, which is referred to as the metallic glass wool in this study, were performed. The metallic glass wool was prepared by lathe-turning a round bar of Zr55Al10Ni5Cu30 metallic glass with different rotation speeds and cutting depths. The specimens were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC). XRD and DSC results exhibited that the crystallinity and the thermophysical properties of the metallic glass wool were almost the same as the metallic glass workpiece. SEM observation revealed that the metallic glass wool was continuous but formed slip planes at almost constant intervals of 7-20μm. In the boundary region between the slip planes, the metallic glass wools slightly and parallelly slid to the slip planes with a very small regular interval. As the metallic glass are generally difficult to produce the plastic deformation, the metallic glass was easily cut off along the shape of the cutting edge. However, the metallic glass chip transformed to supercooling liquid state by the friction heat between the workpiece and the cutting edge. So, the metallic glass chips were easily joined to each other due to the low viscosity, and consequently formed continuous metallic glass wool.

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  • (Experimental Consideration on Suspension Position)
    Kengo OKUNO, Yoshiho ODA, Masahiro KIDA, Toshiki SUZUKI, Takayoshi NAR ...
    Session ID: GS0205
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Thin steel plates are widely used in various industrial products. However, there are problems where deterioration of surface quality and metal plating occurred by transporting. As a solution to these problems, a noncontact transport of steel plate using electromagnetic force has been proposed. However, there is a risk that side slipping or the dropping of the plate may occur. In this study, we carried out experiments that thin steel plate (0.24 mm thickness) was magnetically levitated to discuss the effect of a magnetic field. From the results of the experiments, it can be confirmed that the displacement standard deviation was the lowest at the horizontal electromagnet center distance of 550 mm when the distance between the centers of the horizontal electromagnets was changed and we can obtain the levitation stability.

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  • Hironaga TSUJI, Tsuyoshi OISHI, Daiki TAGAWA, Kazumi TSUNODA
    Session ID: GS0301
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In order to realize a uniform flow distribution to a disk-shape SOFC stack, it is necessary to clarify the optimum structure of a multiple branch channel for SOFC. In this study, we measured velocity profiles between two parallel disk plates, and investigated the effect of the inlet tube diameter and the shape of the channel inlet on the flow rate distribution. The experiment was conducted in the SOFC stack model consisting of three-layers of disk channels to form radial gas flows. In order to obtain the velocity fields in a streamwise-wall-normal plane, we used particle image velocimetry (PIV). Mean velocity vector fields indicated that a recirculation region occupied at the each channel inlet and the flow rate distributed in the channel was suppressed. To change the inflow condition, we installed a coaxial cylinder inside the inlet tube. In this case, the inflow entering the disk channel was accelerated due to the increase in the bulk velocity in the inlet coaxial tube. Moreover, we introduced disk channels with inlet curvature to improve the channel inlet flow fields. This channel structure led to the disappearance of the recirculation region at the channel inlet. It was also found that above mentioned effects caused drastic increase in the flow distribution.

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  • Yuki ARAKAWA, Keisuke NISHIJIMA, Van Cuong HAN, Katsuya Kondo, Naoto K ...
    Session ID: GS0302
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Since magnetic particles are remotely heated by an external alternating magnetic field, they have received a lot of interest to be used for local heating in various fields. For example, one of the promising applications is magnetic hyperthermia in the medical field. When a temperature difference is locally generated by a small heated sphere in liquid, natural convection occurs, and largely affects the temperature and velocity fields. However, a transient temperature field during natural convection in such a small region has never been directly measured. In this study, using the temperature imaging method based on the temperature dependence of the absorption band of water in the near-infrared region, we investigated the natural convection around a 1-mm-dimater magnetic sphere heated inductively in several liquid. By applying the inverse Abel transform to the absorbance profile along each horizontal line in the image acquired by this method, three-dimensional axisymmetric distributions of the absorption coefficient were obtained, and converted to those of the temperature. The results revealed delay time due to natural convection in liquids with different viscosities. Furthermore, these results were verified by comparison with numerical simulation results. This research is expected to be used for clarifying the influence of heat transfer by natural convection.

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  • Keisuke KATAYAMA, Kazuki NODA, Koichi NISHIBE, Hiroshi OHUE, Kotaro SA ...
    Session ID: GS0303
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Radial inlet guide vanes are generally mounted on a centrifugal compessor to contorol flowrate and expand the operating range. When the flow angle measured from the circumferential direction is small (in case of operation in the low flowrate), the flow disturbance with single or multiple cell structure (the pair of high- and low- pressure region) circumferentially propagates downstream of the radial inlet guide vanes. Several experimental and numerical studies have been conducted to clarify the mechanism for generating flow instabilities and their control. However, many issues remain to be resolved to establish more stable operating condition of centrifugal compressor. In present study, It was investigated numerically the effectiveness of the circumferential velocity distribution in the span direction to suppress the flow instabilities. As the results, applying the circumferential velocity gradient to the inward swiring flow is effective in attenuation of the pressure fluctuation amplitude and reducing the generating range of the flow disturbance.

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  • Toru WATANABE, Akitoshi MATSUI, Kiyoshi MORITA, Yukinobu ABE, Yuzo SAT ...
    Session ID: GS0304
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In order to predict the aerodynamic noise of actual railway train, it is important to carry out wind tunnel test as same speed as actual railway train. Therefore, we developed “High speed low noise wind tunnel”. This wind tunnel has mainly three features. The first feature is high-speed wind velocity with low background noise. The second feature is precise aerodynamic noise measurement by wind temperature control. The last feature is that this wind tunnel nozzle is exchangeable to 4 type multipurpose nozzles. These nozzles can provide with precise aerodynamic noise measurement and crosswind assessment, and testing of rotating machinery. And, we confirmed that the velocity uniformity and turbulence level was achieved target performance regardless of aspect ratio of nozzle outlet.

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  • Hiroshi IKEDA, Keita ASANO, Shigeru AOKI, Katsumi KURITA
    Session ID: GS0305
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In recent years, there is an increasing expectation for quality improvement of electronic products such as precision machines and semiconductor wafers. Further cleaning techniques with higher precision and lower environmental burden are required, so various methods have been proposed. Until now authors have been studying ultrasonic cleaning but found that cleaning with ultrasonic waves has the problem of lowering detergency with long washing depending on frequency. To solve this problem, we attempted to use microbubbles and a surfactant in combination for ultrasonic cleaning. As a result, it became clear that washing can be carried out more efficiently by using a surfactant at low frequency, and it can be cleaned at a high frequency by using microbubbles at the same time without remaining oil amount being constant.

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  • Takeru FUKUCHI, Tatsuya KUMAKI, Masatake YOSHIDA, Ashvin Hosangadi
    Session ID: GS0306
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Numerical analysis of vapor-liquid phase change was performed. Real equation of state was used to consider the compressibility of liquid and to reproduce phenomena affected by the speed of sound. An example of such phenomenon is choked flow. The CFD method was inspected by comparing with existing experiments.

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  • Shion KAWASAKI, Kazumi TSUNODA, Katsuaki SUKEGAWA, Yoshiaki YAMASHIRO
    Session ID: GS0307
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Experimental studies on vortex control using two dielectric barrier discharge plasma actuators (DBDPAs) were conducted. In this study, DBDPAs were used to restrict the vortex generated behind the normal flat plate at free stream velocity of 5 m/s. DBDPAs were attached to a back surface of the normal flat plate and a wall surface behind the flat plate. The experiment was carried out in a 200 mm × 200 mm circuit-type wind tunnel with 2000 mm working section. The flow velocity fields were measured by using a particle image velocimetry (PIV). DBD plasma was created using a high voltage power supply with frequency, fp = 4 kHz, and voltage Va = 4 kV, or with fp = 6 kHz, and 3 kV to investigate the discharge condition. It was found that the vortex with negative vorticity was suppressed behind the flat plate by the induced jet along the wall and the back surface of the flat plate when both of the DBDPAs were operated simultaneously. The performance of DBDPAs on vortex control was evaluated by mapping the changes in vortex area ratio against the power consumption. This result showed that the vortex area decreased with power consumption of DBDPAs and the magnitude of vortex area achieved minimum value when both of the DBDPAs were driven.

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  • Kyouichi HAMADA, Kenji AMAGAI, Shin-ichiro KAWASAKI
    Session ID: GS0308
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In order to reduce the VOC (Volatile Organic Compounds) emission from the coating processes, supercritical CO2 was used as the alternative material of thinner component in paint. However, there were few investigations of the characteristics of paint spray with supercritical CO2. In this study, spray pattern and droplet distribution on the coating surface were measured using the high speed camera images under the various conditions of CO2 additive rate. In the experiment, the additive rate of CO2 is changed from 0% to 60%. As a result, it was confirmed that the atomization characteristics was strongly influenced by the additive rate of CO2. And the spray characteristics were enhanced by the additive of supercritical CO2.

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  • Isao ODA, Hiroki IIZUKA
    Session ID: GS0309
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    This paper describes about development of an actuator that uses light energy as a driving source. Light has the advantage of sending information and energy at the same time. Focusing on the energy effect of light, there is a characteristic of high energy density. However, an optically driven actuator has not yet been put to practical use. The authors are developing an optically driven actuator utilizing the volume change of a substance by phase transition from liquid to gas. The authors devised a mechanism in which a flexible tube filled with liquid is inserted into four aluminum pipes separated. By this mechanism, it is possible to realize stable displacement of the actuator and an increase in displacement amount. The authors chose a fluoro rubber tube as a flexible tube and n-pentane as a working fluid. Two types of optically driven actuators were prototyped. One was an actuator used a tube with outer diameter of 7 mm and the other was an actuator used a tube with outer diameter of 5 mm. Both types of actuators were capable of cyclic operations by repeating light irradiation and air cooling. The times required for extension of the actuator were 150 seconds with a tube with an outer diameter of 7 mm and 90 seconds with a tube with an outer diameter of 5 mm. The problems to be solved in the future are to make the diameter of the tube thinner and to prevent leakage of working fluid from the tube.

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  • Mahmudul Hasan, Shirin Sultana, Hiroyuki Hirahara
    Session ID: GS0310
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Self-organization is always observed in crowd of different creatures such as animal herds, fish schooling, human crowd and so on. Using molecular kinetic model, we investigated self-organization phenomena of fish schooling. Two kinds of directional function as well as an influence coefficient were introduced in our model considering field of vision angle of fish and we found that directional functions and influence coefficient were the most important factors to produce self-organization phenomena. Moreover, it was assumed that anisotropic properties of fish schooling would produce the phenomena and computer simulation technique was performed to confirm our assumption. Finally, the criteria of directional function to make self-organization were proposed.

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  • Toshiya OHATA, Daisuke KAWASHIMA, Naoto KAKUTA
    Session ID: GS0311
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    For the design and evaluation of microfluidic applications, it is important to measure concentration distributions of target substances in liquid and to quantify their generation or reduction during chemical reactions. We have thus developed a concentration imaging method for aqueous solutions, based on the near-infrared (NIR) absorption characteristic of water. This method needs to add no substance to the aqueous solutions and can be applied to various aqueous solutions. Moreover, a useful advantage of this method is that it can measure concentrations of multiple substances simultaneously. In this study, when the aqueous solutions of HCl and NaOH were flowed in parallel through a microfluidic channel, the concentration distributions of HCl, NaOH, and NaCl were measured using the NIR-based imaging method, where three wavelengths of 1412 nm, 1442 nm, and 1520 nm in the ν1 + ν3 absorption band of water were used. The concentration images indicated the generation of NaCl by the neutralization reaction and the interdiffusion processes of HCl and NaOH.

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  • Hidenobu KATSUYAMA, Satoru TAKAHASHI, Megumi AKOSHIMA
    Session ID: GS0401
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Thermal barrier coatings (TBCs) are used to protect hot-section components of power-generation gas turbines from hot combustion gases. The TBC consists of a metallic bond-coat (BC) and a ceramic top-coat (TC) on the superalloy. The thermal barrier effect of the TBC depends strongly on the thermal conductivity of the TC. Since there are interfaces in components to which the TBC is applied, the interfacial thermal resistance between the layeres must be also understand. In this study, we investigated the effect of the heat treatment on the thermal conductivities of the TC and the BC, and the interfacial thermal resistance between the TC and the BC. TBC and BC specimens with different coating thickness were prepared by thermal spraying. Some specimens were subjected to the heat treatment in air. In addition, the cross-sectional microstructure of the specimens was investiagated using SEM. It was found that there is the interfacial thermal resistance between the TC and the BC in the as-sprayed TBC specimen. The interfacial thermal resistance was caused by the local non-contact region between the TC and the BC. The development of the thermally grown oxide (TGO) by the heat treatment in air improves the contact between the TC and the BC, and decreases the interfacial thermal resistance.

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  • Yohei KOMURO, Yoshinori MIYAMOTO, Masayuki NAKAYAMA, Atsushi AKISAWA
    Session ID: GS0402
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The temperature of waste heat from a data center is about 40°C. The waste heat is not reused and thrown away. It is important to use it for other facility. The objective of this study is to build an optimum operation model to balance supply and demand of energy. The system consists of a heat pump, a hot water tank and tap water. Waste heat from the data center is recovered by the heat pump. The compressor of the heat pump is operated in response to heat demand. In this study, mass flow from the condenser to the hot water tank, and mass flow of tap water are assumed constant. The optimum operation is calculated with minimum use of electric power as the objective function. As the result, with given demand data electric power consumption is minimum when the mass flow from the condenser to the hot water tank is 0.3 [kg/s] and the mass flow of tap water is 0 [kg/s]. The model needs to involve a boiler in the system to be operated flexible.

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  • Keisuke NISHIJIMA, Naoto KAKUTA, Katsuya KONDO, Yukio YAMADA
    Session ID: GS0403
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    This paper presents a determination method of heat production rates in a 1-mm-diameter magnetic sphere at different positions in a magnetic field. In this method, three-dimensional radial temperature distributions of water around the sphere were obtained by the inverse Abel transform of two-dimensional radial profiles in absorption images at a wavelength of 1150 nm, at which the absorption coefficient of water depends on temperature. Through minimizing the residuals between the measured temperature distributions and the numerical solutions of thermal conduction equation, heat production rates were determined. Finally, a two-dimensional map of the heat production rates, corresponding to the distribution of magnetic field intensity, was constructed and discussed.

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  • Mikiya WATANABE, Riki MIYAWAKA, Naoto KAKUTA
    Session ID: GS0404
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Analyses of substances by plasma is one of the developing techniques. Analyses using plasma have problems that need a vacuum device and a large amount of samples. We invented an electrode construction which generates plasma combined corona discharge generating sustainable in the ambient air and barrier discharge to approach to a dielectric to solve the problems. We have researched affections to measuring emission spectra and discharge voltages by conditions of liquid or gas samples using micro glow corona generated the tip of the needle electrode which size is based on the size of the needle tip in the past research. It is the purpose of this research to clear the potential of generated plasma to analyses of substances.The needle electrode, the hollow electrode and the plate electrode were used as electrodes. Hollow electrode make samples to approach plasma generated around the tip of the needle electrode easily.Silicone was used as a solid sample and water, pure ethanol, NaCl aq (3.4 M) and HCl aq (2.0 M) were used as liquid samples.Analyses of a minute amount of substances were performed by generated plasma. An new electrode construction we invented can approach samples to plasma easily.Plasma made a change on the solid sample surface and made changes in discharge voltages by characteristic of samples.

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  • Takashi NAKAYA, Shuhei YAMANO, Masayuki NAKAYAMA, Takashi IKEGAMI, Ats ...
    Session ID: GS0502
    Published: 2018
    Released on J-STAGE: September 25, 2018
    CONFERENCE PROCEEDINGS RESTRICTED ACCESS

    There is a cogeneration system(CGS) as a method of efficient use of energy. The overall efficiency of the CGS is 70 to 85%, but there is a problem that the total efficiency is influenced by other equipment making up the system. In this research, we focus on gas engines among equipment. Gas engines are divided into high speed type and middle speed type, maintenance is the most important factor among those characteristics. The purpose of this research is to focus on the type composition at the time of introducing a plurality of gas engines and the maintenance of each kind, and to evaluate the technical selection by comparing various kinds of constructions from the economic point of view. For this purpose, the timing of maintenance and the output of the gas engine accompanying it are also calculated in the optimization simulation. Temporary demand for this time is 31 days in January, and the maintenance span was set as 1/10 of the original, and conditions were set up to introduce three types of maintenance for each of high speed and medium speed type. Furthermore, no grid electric power is used, and it is said that a total of 3 gas engines can be installed at 4000 kW gas engine. As a result, all three equipments operated evenly in the case of 3 middle speed type. In addition, in the case of other configurations, one high-speed model protruded and operated, and the other two were operated so as not to perform the second or third maintenance, which is related to the maintenance span greatly. In this case, simulation using provisional data was carried out, but considering the parameters as original things in a long period of 5 to 10 years or the like seems to be able to consider reality.

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  • Satoru TAKAZAWA, Motohiro INAGE, Michio NAKANO
    Session ID: GS0503
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In this study, exhaust gas components emitted from SI combustion were analyzed using a comprehensive two-dimensional gas chromatograph (GC×GC) with a time-of-flight mass spectrometer (TOFMS). N-heptane and isooctane were used as fuels. As a result of the analysis, it was found that aromatic hydrocarbons in the exhaust gas were influenced by the molecular structure of the fuel.

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  • Motohiro INAGE, Satoru TAKAZAWA, Michio NAKANO
    Session ID: GS0504
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In this study, exhaust gas components emitted from spark ignition engine were analyzed using a comprehensive two-dimensional gas chromatograph (GC×GC) with a time-of-flight mass spectrometer (TOFMS). Cyclohexane and toluene were used as fuels. As a result, the influence of molecular structure on exhaust gas was clarified. In the case of using cyclohexane, it is considered that ring structure, straight chain, and aromatic compounds are important. In the case of using toluene, it is considered that aromatic hydrocarbons are important.

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  • -Especially effects of impinging injection timing-
    Shun TERAKADO, Tadashige KAWAKAMI
    Session ID: GS0505
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    This experiment has been carried out to examine the combustion characteristics of heterogeneous combustion field by using Impinging injection and Split injection in a closed bomb. The combustion chamber is equipped with pintle type injection nozzles on each of the opposite walls along the length of the bomb. In this study, we call it “Impinging injection” when the injection is performed at same time by two nozzles facing each other and “Split injection” when the injection is performed at different timing from the ignition.

    The main conclusions are as follows; 1) The most suitable condition of injection timing exist for improving the maximum burning pressure and total burning time by using Impinging injection. 2) The flame speed can be possible to control by using Impinging injection timing from the ignition. 3) The heat release rate for Split injection is larger than that of standard Impinging injection.

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  • Yiyang LIU, Tadashige KAWAKAMI
    Session ID: GS0506
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    Nowadays, biomass fuels become a subject which is extensively concerned from the view points of the aggravation of the greenhouse effect, acid rain, other environmental problems and the depletion of oil resources. From the point of this view, this experiment has been carried out to examine the influence of combustion characteristics and exhaust emissions for small diesel engine by using ethanol-light oil blended fuels and emulsified fuel of ethanol. The combustion behaviors, such as burning pressures, heat release rate and emissions (CO, HC, NOX, Smoke) are observed. The main conclusions are as follows: 1) HC and CO emissions of ethanol-light oil blended fuels are bigger than that of light oil. 2) It is possible to reduce the NOX and smoke emissions by using ethanol-light oil blended fuels. 3) NOX emissions can possible to reduce by using ethanol emulsified light oil under high load engine conditions.

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  • Hiroyuki SHIRAKAWA, Tadashige KAWAKAMI
    Session ID: GS0507
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    In recent years, as the energy demand has increased, the increase in the emission of environmental pollutants such as nitrogen oxides and carbon dioxide has become more serious. In addition, it is also necessary to consider that the most of energy is dependent on fossil fuels. As a solution to these problems, the use of ethanol and utilization of lean burn have attracted attention. From the based on the idea of carbon neutral, ethanol can possible to control the emission of carbon dioxide. Moreover, when ethanol aqueous solution is used as fuel, reduction of combustion temperature can be expected to reduce nitrogen oxides. However, it is well known that the ethanol aqueous solution and lean burn are concerned about decrease of the flame speed and appearance of the irregular flame shape.

    These experiments have been carried out to examine the combustion characteristics of ethanol aqueous solution-air mixtures by using flame propagation in a tube. The main conclusions are as follows: 1) Flame speed decreases with the increasing the addition ratio of water in ethanol aqueous solutions. 2) The reduction ratio of flame speed increases with the increasing the addition ratio of water in ethanol aqueous solutions.

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  • Shigenori IMAFUKU, Ryota KOJIMA, Shita MITSUDA, Takakazu MORITA
    Session ID: GS0508
    Published: 2018
    Released on J-STAGE: September 25, 2018
    CONFERENCE PROCEEDINGS RESTRICTED ACCESS

    Low-frequency pressure pulses have often been observed in the oscillatory combustion of hybrid rocket motors. However, the mechanism of their occurrence is not well-understood yet. In the present study, we conducted the combustion tests for a wax fuel using a two-dimensional combustor. We modeled the mechanism of the low-frequency combustion instability that causes the pressure pulses.

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  • (Collsion Avoidance System at Lane Change)
    Ryohei MAKI, Hirohiko OGINO
    Session ID: GS0601
    Published: 2018
    Released on J-STAGE: September 25, 2018
    CONFERENCE PROCEEDINGS RESTRICTED ACCESS

    In recent years, active safety that recognizes danger beforehand and conducts danger avoidance attracts attention. However, active safety at existing lane change is only warning. In the proposed system, when the driver intends to change the lane in a running state in which parallel running vehicles exist, the system observes the condition around the vehicle and makes a risk judgment as to whether or not to collide. In this report, a prototype of a 1/10 scale experimental vehicle was tried to realize a collision avoidance system at the time of lane change, and the system operation condition by the experimental vehicle was confirmed.

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  • (Fundamental Consideration on improvement of ride comfort using VCM)
    Ayato ENDO, Keigo IKEDA, Hideaki KATO, Takayoshi NARITA, Hiroyuki MORI ...
    Session ID: GS0602
    Published: 2018
    Released on J-STAGE: September 25, 2018
    CONFERENCE PROCEEDINGS RESTRICTED ACCESS

    In recent years, ultra-compact mobility has been used as new transportation in tourist spots and urban areas. This ultra-compact mobility is an electric automobile for 1 or 2 passengers and is currently being sold by several automobile manufacturers. However, due to lightweight, ultra-compact mobility is subject to vibration from road irregularities and road surface steps. Therefore, it is necessary to develop a vibration control system for safe and comfortable driving. We have proposed vibration control device "active seat suspension" to improve ride comfort. We previously studied a vibration control method by active seat suspension using voice coil motor for actuator. it is necessary to grasp the thrust characteristics when the motor is greatly displaced to make comfortable car for occupant. Therefore, in this paper, we use magnetic field analysis the thrust characteristic of the voice coil motor to confirmed. We investigated the thrust decreases when the position is distant from center of stroke. In the future, it is necessary to realize a system that weights variables other than displacement in order to further improve ride comfort. Therefore, it is required to construct a control system that is robust against changes in the thrust constant due to displacement. Furthermore, it is necessary to estimate the input vibration in detail in advance and design a motor that can exert sufficient thrust against the displacement.

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  • (Fundamental Consideration on Exposure of Vertical Vibration)
    Keigo IKEDA, Ayato ENDO, Hideaki KATO, Takayosi NARITA, Hiroyuki MORIY ...
    Session ID: GS0603
    Published: 2018
    Released on J-STAGE: September 25, 2018
    CONFERENCE PROCEEDINGS RESTRICTED ACCESS

    Nowadays, demand for single- and two-seater ultra-compact electric vehicles have been increasing in Japan. Unlike general cars, ultra-compact EVs are able to easily drive on a narrow or unpaved road. Being lightweight, however, it is subject to vibration from road irregularities and road surface steps, and it is necessary to develop a vibration control system for safe and comfortable driving. To improve ride comfort against up-and-down vibration, our research group proposed an active seat suspension using a voice coil motor at the seat section of the vehicle. The active seat suspension directly controls the seat section, which is independent of the vehicle body. Evaluate by focusing on brain communication which is new biometric information t is possible to perform accurate experiment strongly against shearing vibration using a cerebral blood flow meter.

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  • Keisuke MATSUMOTO, Isoharu NISHIGUCHI, Masao ISHIHAMA, Kuniaki YOSHII, ...
    Session ID: GS0604
    Published: 2018
    Released on J-STAGE: September 25, 2018
    CONFERENCE PROCEEDINGS RESTRICTED ACCESS

    In this study, transmission of tire cavity resonance sound, which is one of the main causes of road noise, was analyzed. First, the propagation of sound waves inside the tire cavity was numerically analyzed by finite-difference time-domain method. The analysis was a cylindrical coordinate system, and the wheel was calculated as a rigid body, the tire inner air as a fluid, and the tire tread as an elastic body. Also, the sound pressure inside the cavity was measured by a sensor attached to the wheel. As a result, it is possible to visualize the state of the wave propagation of air in the tire cavity, and it was found that complicated wave propagation is caused by reflection and diffraction phenomena. In addition, it was found that the structure of the tire has an effect on the cavity resonance.

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  • Hirosuke HORII, Yuichi MATSUMURA
    Session ID: GS0605
    Published: 2018
    Released on J-STAGE: September 25, 2018
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    The aquatic propulsion mechanism by using vibrating elastic plate obtains propulsion force from traveling waves on the plate generated by vibrating a leading edge on the plate. But reduction of the propulsion force is caused by generating standing waves. The standing waves are generated by superposition of the traveling waves and the reflected waves generated at the rear end. In order to improve the propulsion force, suppression of the reflected waves by adding translational control and rotating control on the rear end is considered. The above plan is validated by using SPH analysis.

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