-
Article type: Cover
Pages
Cover1-
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Appendix
Pages
App1-
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Appendix
Pages
App2-
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Appendix
Pages
App3-
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Article type: Index
Pages
A1-A9
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Tomonori YAMAMOTO, Shingo NISHIDA, Nobuyuki OSHIMA, Yoshiharu NONAKA
Article type: Article
Session ID: J0101-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Under high temperature combusting environment, very high level of thermal NOx is generated. In order to prevent environmental problems and pursue more power generation efficiency, we need to investigate the ability of our numerical prediction method in a practical combustor system. We predict time-averaged temperature in the 1300degC class gas-turbine combustor that is a commercial model fabricated by Kawasaki Heavy Industries, Ltd. The results show LES and 2-scalar Flamelet approach is effective to predict phenomena in practical gas-turbine combustor.
View full abstract
-
Takashi FURUSAWA, Satoru YAMAMOTO
Article type: Article
Session ID: J0101-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The supercritical-fluids simulator (SFS) developed by our group is applied to turbulent flows near critical point with heat transfer. In SFS, a numerical method based on the preconditioning method coupled with the PROPATH is used. In this paper, turbulent flows of supercritical carbon dioxide in a tube are calculated in several temperature conditions. The calculated results are compared with each other and the heat transfer coefficients are compared with the existing experimental results.
View full abstract
-
Ryo MATSUZAWA, Satoru YAMAMOTO, Takashi FURUSAWA
Article type: Article
Session ID: J0101-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Our research group has proposed a numerical method for supercritical fluids; Supercritical Fluid Simulator (SFS). In SFS, a numerical method based on the preconditioning method coupled with PROPATH is used. In this paper, we compute a supersonic free-jet assuming gas using SFS. Next, we compute a supersonic jet of supercritical CO_2 impacting on a flat plate with the drastic pressure decrease near the critical point. In both simulations, our results show good agreements with the experimental data. These results indicate the importance of numerical models considering accurate thermophysical properties for simulating supersonic flows of supercritical CO_2, such as RESS-process.
View full abstract
-
Masaya SUZUKI, Makoto YAMAMOTO
Article type: Article
Session ID: J0101-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Our research group has proposed a numerical method for supercritical fluids; Sand erosion is a phenomenon whereby solid particles impinging on a wall cause serious mechanical damage to the wall surface. This phenomenon is a typical gas-solid two-phase turbulent flow and can be considered as a multi-physics problem in which the flow field, particle trajectory, and wall deformation interact. On the other hand, aircraft engines operating in a particulate environment are subjected to the performance and lifetime deterioration due to sand erosion. Especially, the compressor of the aircraft engines is severely damaged. In the present study, we apply our three dimensional sand erosion prediction code to a single stage axial flow compressor. We numerically investigate the change of the flow field, the particle trajectories, and the eroded wall shape in the compressor, to clarify the effects of sand erosion in the compressor.
View full abstract
-
Shogo TAHARA, Masaya SUZUKI, Makoto YAMAMOTO, Kazuyuki SAKAMOTO
Article type: Article
Session ID: J0101-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, terrorism with chemical weapons is one of most daunted danger in the world. Chemical terror have particularly high mortality rate. VX gas is one of chemical agent used to commit terrorism. VX gas has severe toxicity and long-period damage because of persistent agent. In the present study, VX gas emission from a contaminated object surface is researched. VX gas emission is unusually analyzed with experiments, since the experiment is so dangerous because of the toxicity. Therefore, in this study, computational fluid dynamics is used to analyze the emission. We propose a volatilization model which estimates the volatilization quantity of a chemical agent with the saturated steam pressure of chemical agent and physical quantities of the air. Since the volatility characteristics of VX gas resembles that of glycerin, the model is applied and verified to glycerin volatility tests. The numerical results are compared with the experimental data.
View full abstract
-
Hiroshi NAGATOMO, Masaya SUZUKI, Makoto YAMAMOTO
Article type: Article
Session ID: J0101-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Sand erosion and deposition are factors of fatal damage and performance deterioration of gas turbines. Both phenomena are caused by collisions of solid particles with a solid surface. To protect gas turbines from these fatal problems, it is important to know the behavior of solid particles in gas flow. In general, oblique shock waves take place in the passages of transonic compressor where the fatal phenomena may occur. However, the behavior of the solid particle passing through an oblique shock wave is not well known. We numerically investigate the effects of gravity force, drag force, added mass force, pressure gradient force, and Magnus force on the motion of solid particles which pass through an oblique shock wave.
View full abstract
-
Sojuro WATANABE, Masaya SUZUKI, Kazuaki INABA, Makoto YAMAMOTO
Article type: Article
Session ID: J0101-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Two-dimensional computations of propagating detonations in a stoichiometric hydrogen-air mixture diluted with nitrogen or argon were perfbrmed using a detailed chemical reaction mechanism Previous computational studies on detonation have not usually considred viscosity. In this study, we considered viscosity and calculated the behavior of shock induced boundary layer. From the results, we estimated the effects of viscosity on the characteristics of detonation. The velocity distributions in the boundary layer were verified by the theory of Sturtevant-Okamura. We investigated the effects of viscosity on cellular structure by examining pressure distribution, and trajectory of triple points.
View full abstract
-
Atsuhiro YUASA, Masahiro SAKAMOTO, Makoto YAMAMOTO, Yasuo KAWAGUCHI
Article type: Article
Session ID: J0101-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Yearly, the concern on environmental problems of the earth is growing on. One of the typical issues is desertification. To inhibit harmful effects of desertification, confirmed prediction methods which clarify mechanism of desertification are required. It is expected that numerical simulations are useful for the purpose. However, the numerical procedure and the physical model for predicting have not been established yet. Hence, our purposes are to construct the holistic simulation technique which reasonably reproduces sand transfer, and to apply it to create an effective prevention method of desertification. In this study, three dimensional simulations are carried out in order to compare our results to experimental data. Though results are qualitatively similar to experimental data, quantitatively-correct results are not obtained.
View full abstract
-
Ryo TSUBOI, Makoto YAMAMOTO
Article type: Article
Session ID: J0101-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Electro-Chemical Machining (ECM) is an advanced machining technology and has been applied to highly specialized fields, such as aerospace, aeronautics, and medical industries, However, some problems remain to be solved The efficient tool-design, electrolyte processing, and disposal of metal hydroxide sludge are typical problems. In the previous study, we presented models to calculate the flow fields in an ECM process based on one- and two-way coupling simulation for interactions between gas and liquid phase. And we verified the presented models by comparing the numerical results with the experimental data for a flat plate electrode configuration. In this study, we apply the models for an ECM process for a compressor blade and compare the blade geometry.
View full abstract
-
Yasuhiro SUNAGA, Shigeho NODA, Shin YOSHIZAWA, Daichi OBINATA, Hideo Y ...
Article type: Article
Session ID: J0102-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We have been working to develop a novel 3D cell simulation platform. Cell inside is divided by complicated membrane structures such as organelles. In this study, we propose new model of selective permeability and receptor functions. The models are implemented in our platform. The platform is based on calculating is the biochemical reaction-diffusion and membrane transporter functions, simultaneously. We will show the capabilities of our platform to understand the cellular functions
View full abstract
-
Yohei NANAZAWA, Noriko TAMURA, Shinya GOTO, Seiichi TAJIMA, Hitoshi KA ...
Article type: Article
Session ID: J0102-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We develop a basic model of platelets as a cell forming thrombi. In the model, the platelet intracellular reaction is produced by the contact of the platelet with a vessel injury area. According to this reaction, adhesions and agglutinations of the platelet occur. In this report, we append the weak coupling with the platelet and blood plasma flow to this model.
View full abstract
-
Kenichiro KOSHIYAMA, Shigeo WADA
Article type: Article
Session ID: J0102-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Coarse grained molecular dynamics simulations of pulmonary-surfactant monolayers on a water layer are conducted to understand phase changes of the monolayer under various area per lipid (APL) in the molecular level. The monolayer is modeled by a monolayer comprised by dipalmitoylphosphatidylcholine (DPPC) molecules, which are the major component of human pulmonary surfactant. The area of the system calculated is varied according to APL from 0.40 to 0.80 nm^2/lipid, whereas the system size in the monolayer normal direction is 100 nm. The constant temperature and volume MD calculation is performed in 30 ns for each APL condition. Visual inspection of the hydrophobic-beads packing shows the monolayer calculated is in the lipid-condensed (LC) phase for APL=0.45, in the lipid-expanded (LE) phase for APL=0.70, in the LE and LC coexisting (LE/LC) phase for APL=0.50, and in the LE and the uncovered water layer coexisting (LE/G) phase for APL=0.70. In addition, the monolayer buckles for APL=0.40. The results obtained here agree with available experimental data.
View full abstract
-
Shingo SUZUKI, Shigeho NODA, Shu TAKAGI, Shigeo WADA
Article type: Article
Session ID: J0102-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
CT images of lung are generally used for diagnostics of respiratory diseases. However, there is no system to estimate the function of lung from images quantitatively. In this paper, we report the analysis of the pulmonary airflow and oxygen transport by voxel image based 3-D simulation. We used the voxel data which was consist of bronchi having the diameter larger than 1.5 mm. The oxygen transport by advection and diffusion are treated by CIP method. Calculated pressure profile along the direction of airflow was consistent with l-D analytical estimation. We could also reproduce the pressure profile and the time-dependence of asymmetric bifurcation flow. The axial and the transverse profiles of oxygen concentration showed the behavior of the time development of gas mixture on the asymmetric air passages in lung. The method of this study can be applied to quantitative diagnostics of respiratory diseases.
View full abstract
-
Yutaro Fujino, Makoto Tanaka, Shimpei Kohri, Tsutomu Tajikawa, Atsushi ...
Article type: Article
Session ID: J0102-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
For all people using speech language, it is very important to detect the symptoms of a laryngeal disease like an abnormal voice as soon as possible for the quick recovery and to find medical treatments. This study is to clarify a phonatory mechanism, and aims to be applied to the medical treatment support technology. For that purpose, in vitro experiment using elastic thin film modeled after human vocal folds was performed. In the experiment, the glottal width and amplitude were measured using high speed video camera and microphone with the glottal width and the anterior commissure angle were changed gradually. As a result, it was found that the laryngeal source was generated when glottis was open and closed, and the vibration sound was generated when the anterior commissure angle was over 6 deg.
View full abstract
-
Naoto YAMAMURA, Luis ALVES, Toshiaki ODA, Cristian TEODOSIU
Article type: Article
Session ID: J0102-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A 3D finite element software devoted to the numerical simulation of both the mechanical behavior of soft tissues and muscle activation is under developed. Its formulation is based on large strains and almost incompressibility of hyperelastic media, in case of passive part of muscles' behavior, while the active one is described by a function of fiber length, shortening velocity and activation level of muscles' fibers. Due to the incompressibility character of the biological soft-tissues, a mixed type displacement-pressure finite element formulation is adopted. One exemplifies with the contraction of a muscle-tendon structure of the back part of a human lower leg. The finite element model represents a real human muscle-tendon complex measured by magnetic resonance imaging device.
View full abstract
-
Koji NISHIGUCHI, Shigenobu OKAZAWA
Article type: Article
Session ID: J0102-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A solid-solid-fluid interaction scheme is developed for biomechanics simulation. The scheme is based on full Eulerian formulation, which is familiar with medical voxel data. Both solid arid fluid are modeled as an incompressible material and one governing equation treats equations by using the volume fractions of the materials. Both FEM and FDM are used for space discretization of fixed structural mesh. PLIC (Piecewise Linear Interface Calculation) method is used to capture the material interfaces with high accuracy and to impose boundary conditions on the material interfaces.
View full abstract
-
Hiroyuki KATAOKA, Shigeho NODA, Hideo YOKOTA, Shu TAKAGI, Shigenobu OK ...
Article type: Article
Session ID: J0102-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, we developed a new method for Eulerian hydrocode to represent a solid-solid stick interface in a voxel where multiple solids were included. In this method, individual velocity gradient tensor was assumed for each solid associated with normal vector of the contact area between solids, and determined by solving the equation of force balance on the contact area. We also investigated the accuracy of displacement around the contact area using a layered objects under shearing deformation, and compared the results with those of theoretical solutions and conventional Mixture theory. As the results, in the case that the contact area was on the voxel border, the displacement matched with the theoretical solution as well as the Mixture theory. However, in the case that the contact area was inside voxel, the displacement had still large error, which didn't derive from the individual velocity gradient tensor for each solid.
View full abstract
-
Kazuyasu SUGIYAMA, Satoshi II, Shintaro TAKEUCHI, Shu TAKAGI, Yoichiro ...
Article type: Article
Session ID: J0102-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A new simulation method for solving fluid-structure coupling problems has been developed. All the basic equations are numerically solved on a fixed Cartesian grid system in a finite difference scheme. A volume-of-fluid approach, which has been developed for computing multiphase flows, is applied to describing the multi-component geometry. The temporal change in the solid deformation is described on the Eulerian frame by updating a left Cauchy-Green deformation tensor, which represents constitutive equations for the hyperelastic Cauchy stress. The present simulation method is applied to problems of hydrodynamic interactions among several neo-Hookean materials.
View full abstract
-
Satoshi II, Shintaro TAKEUCHI, Kazuyasu SUGIYAMA, Shu TAKAGI, Yoichiro ...
Article type: Article
Session ID: J0102-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The main idea of the Eulerian fluid-structure interaction (FSI) model is derived from the idea of the multi-phase analysis on fixed Cartesian mesh. Usually, the approximate stress is averaged by fluid stress and solid stress with each volume fraction. Due to such simple averaging procedure, the numerical approach is reduced to first order accuracy. In this paper, an accurate numerical approach is applied for the Eulerian FSI model with using physical jump condition at the interface on fixed Cartesian mesh. Moreover, an implicit treatment of stress evaluation in elastic material which is based on linearization with the Jacobian in time is proposed. In addition, a result of FSI problem with pseudo-blood vessel will be shown toward application of a real blood flow simulation.
View full abstract
-
Hirotaka HADACHI, Takashi SAITO
Article type: Article
Session ID: J0102-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, many diagnosis devices utilizing light scattered by biological tissue or a cell have been developed. Then understanding of characteristics about light propagation and scattering in biological tissue plays an important role. To investigate those in time domain, we applied FDTD, CIP and IDO method to Maxwell's equations and investigated those accuracy. About in uniform medium, it is found that FDTD method excels at calculating only time averaged intensity and CIP method can analyze phase of waveform with high accuracy, and IDO method has highest accuracy among those methods. Finally, In the case that an infinitely long cylinder is existed in analytical area, scattering light is calculated. The results show that IDO method could have a problem depending on relation between physical value and the special derivation value on the boundary between materials.
View full abstract
-
Kenichi L. ISHIKAWA, Shu Takagi, Koen MATTHYS, Shigeo WADA
Article type: Article
Session ID: J0102-3-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
To enable the evaluation of the impact of respiratory motion on charged particle therapy and to realize 4D treatment planning while keeping CT exposure as low as possible, we are developing a Monte Carlo dose calculation system combined with the spring network model of lung motion. The calculated 3D shape of the lung for a given phase is transformed to a voxel data set. For each phase, assuming carbon-ion beam irradiation, biological dose distribution is calculated using the Monte Carlo particle and heavy ion transport code PHITS coupled with a microdosimetric kinetic model. The dose is mapped onto the reference data set to obtain the accumulated dose. The first version of the 4D dose calculation system we have developed so far can successfully read the data set for each phase and calculate the accumulated dose. The number of the phases to be sampled and their weights can be set arbitrarily, without need of additional CT scanning. Our results indicate that the dose distribution can significantly change with phase and that many data sets may be needed to accurately evaluate the dose to the surrounding normal tissue.
View full abstract
-
Kohei OKITA, Kenji ONO, Kazuyasu SUGIYAMA, Shu TAKAGI, Yoichiro MATSUM ...
Article type: Article
Session ID: J0102-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The development of High Intensity Focused Ultrasound (HIFU) therapy for the treatment of deeply-placed tumor has been desired. Problems are the displacement of focal point due to the reflection and refraction of ultrasound at the interfaces of bones and the attenuation of ultrasound due to the skins, fat and tissues. To minimize the invasive region of tissues by HIFU, the numerical simulation is available for the prediction of the treatment of tissues. In the present study, the HIFU therapy for the liver tumor is represented numerically. The simulation with the heat coagulation shows that the increase of acoustic impedance due to the coagulation causes the scattering of ultrasound at the interface of the coagulation region, which then develops toward the transducer. Therefore, the influence of the heat coagulation of tissue on the acoustic field should be considered to predict the treatment region precisely.
View full abstract
-
Tatsushi TOKUYASU, Kenji YUFU, Takashi SHUTO, Norihiro ABE, Akira MARU ...
Article type: Article
Session ID: J0102-3-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In the phase of operative planning for large artery, preoperative patient's medical image data has been used as the most important information. Especially, three dimensional computer tomography data using contrast agent is available because the surgeons can recognize the inner wall of large artery. However, due to thrombuses in aneurysm, the tomography data can not give the surgeons enough information to let them completely know the statement of aneurysm. This study aims to develop a diagnosis support system for large artery operation, where the system firstly estimate the shape of aneurysm from preoperative patient's tomography data and render the large artery including aneurysm on a computer display. Additionally, the surgeons can virtually palpate it with a haptic device. This paper presents a method to extract the shape of large artery from patient's three dimensional computer tomographic images, and shows a dynamic model specified at the virtual artery model.
View full abstract
-
Manabu TAKAHASHI, Jyouji SHIGEMOTO, Nobuhiro SETTSU, Keiji OGI
Article type: Article
Session ID: J0103-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Shear loading tests were executed to ceramics/metal joints used for an electronic device in various temperatures and loading rates. Fracture origin of the joints is formed from ceramics of interfacial neighborhood. According to FEM analysis, it is clarified that the driving force for the failure is not a shear stress but a tensile stress. The tensile stress dramatically decreases from just beneath the surface to interior portion. Slow crack growth behavior in nominal shear stress was estimated using fracture mechanics in the different conditions of loading rates.
View full abstract
-
Masaaki KOGANEMARU, Keisuke YOSHIDA, Toru IKEDA, Noriyuki MIYAZAKI, Ha ...
Article type: Article
Session ID: J0103-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The effects of stress on the DC characteristics of n-type Metal Oxide Semiconductor Field Effect Transistors (nMOSFETs) were evaluated by mechanical stress simulation and drift-diffusion device simulation (multi-physics simulation). The simulation focused on the impact of the stress distribution in the nMOSFETs. From the simulation results, it was demonstrated that the stress distribution in the device affected the DC characteristics of the device.
View full abstract
-
Yukihiro KUMAGAI, Hiroyuki OHTA, Masahiko Fujisawa, Takeshi Iwamoto, A ...
Article type: Article
Session ID: J0103-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Delamination failure of a low-k interlayer dielectric (ILD) layer of Cu/low-k multi-layer interconnects during a thermal cycle test was investigated by mechanical stress simulation. A 3D zooming analysis was used to analyze the stress that occurred in a fine-scale film stack in a large-scale package. The maximum stress occurred at the low-k/cap film interface that was bottom surface of the low-k ILD layer. The interface agreed well with the delaminated interface. And it was able to explain the yield of the sample with different structure by the stress. This method is useful for reducing delamination failure.
View full abstract
-
Yasuhisa FUJIMOTO, Mitsuru SATO, Shinichi TAKAGI
Article type: Article
Session ID: J0103-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Copper base have been used for many semiconductor package to satisfy thermal radiation performance. However, copper base is easily deformed and curvature deformation increases during thermal cycle. In this research, the effect of temperature condition on copper base deformation during thermal cycle is evaluated quantitatively through experiments and finite element analyses (FEA). As a result, the more minimum temperature of heat cycle increases, the more curvature deformation decreases because plastic deformation of copper decrease. On the contrary, the more maximum temperature of heat cycle decreases, the more curvature deformation decreases because solder creep decreases. Therefore this phenomenon of curvature deformation is sensitively controlled by the temperature condition of thermal cycle. The results of elasto- plastic FEA that considers plasticity of copper and solder creep deformation agree well with the experimental result under various thermal cyclic conditions.
View full abstract
-
Hideo KOGUCHI, Masahiro YOSHITAKE
Article type: Article
Session ID: J0103-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, an advanced chip size packaging technology is important for developing portable electronic devices. Chip size package (CSP) is composed of IC, sealing resin and the substrate. Warp deformation occurs by temperature change due to the difference of thermal properties of each material. In this study, thermo-viscoelastic analysis of CSP using a simple theory based on a multi-layer plate theory is presented. In comparison with FEM, the method is simple and various analysis conditions such as reflow process can be considered easily. When temperature cooled down from 453K of the bonding temperature to 298K in the room temperature, the amount of warpage is predicted and compared with the results of FEM analysis.
View full abstract
-
Toshifumi KANNO, Nobuyuki SHISHIDO, Toru IKEDA, Noriyuki MIYAZAKI, Hir ...
Article type: Article
Session ID: J0103-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, we evaluated the strain distribution in flip chip (FC) packages by the FEM analyses and the digital image correlation method (DICM) measurement. The evaluation was carried out for four types of FC packages which consisted of two types of buildup (BU) resin and two types of underfill (UF) resin. The results show that the lower coefficient of thermal expansion (CTE) of resin reduced thermal strain around solder bumps. We also compared the DICM measurement with the FEM analyses. This comparison shows that the concentrated region of shear strain obtained by the FEM was the reverse of that obtained by the DICM in packages with OF-1 that has higher CTE. We found out the higher Poisson's ratio of OF-1 at higher temperature may change the distribution of shear strain around a solder bump. The distribution of shear strain around a solder bump analyzed by the FEM with the higher Poisson's ratio (=0.48) of OF-1 resin approached that measured by the DICM.
View full abstract
-
Taku Kawai, Joao Gaspar, Vu Le Huy, Oliver Paul, Shoji Kamiya
Article type: Article
Session ID: J0103-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper presents the possibility of fatigue lifetime prediction of polycrystalline silicon films under cyclic loading. Fatigue crack extension process determining fatigue lifetime was formulated by the well-known Paris law with two unknown parameters. These parameters were fit to the results of the tensile fatigue tests performed on specimens with three different conditions of etching damage. The optimum values and the average values of them were applied to predict fatigue lifetime distribution, which showed that fatigue behavior of polysilicon can be approximately estimated with common values of two unknown parameters of the Paris law.
View full abstract
-
Nobuyuki ISOSHIMA, Masatoshi WATANABE, Mika Ri, Yutaka Yamada, Koichi ...
Article type: Article
Session ID: J0103-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A low-noise and high-performance "inclined fan-blowing-upward structure" for full high definition plasma display panel television sets was developed by using computational fluid dynamics with heat transfer based on a Cartesian grid system. In the conventional structure, the plasma panel and boards are cooled by fans and upward flow induced by natural convection. However, simulation results indicated that low-temperature flows between the bottom and rear inlets and fans are formed along the back cover, and the flows are not sufficiently supplied to the plasma panel and address-driver modules. Our solution is to mount the cooling fans inclined to the plasma panel so that the flows produced by the fans impinge on the panel to supply the low-temperature air to the panel and address-driver modules directly. In the new structure, larger fans can be used because fans are mounted inclined. With the larger fans, the rotation speed of the fans can be reduced, and the flow rate is increased. The experimental results show that the temperature of the panel and address-driver modules decreases respectively 3℃ and 8℃ at the same noise output level. The cooling structure was applied to a 50" class Full-HD PDP TV set, which achieved the industry's leading contrast ratio of 30,000:1 in April 2008.
View full abstract
-
Yasushi KOITO, Yuta SHIKI, Masataka MOCHIZUKI, Toshio TOMIMURA, Shuich ...
Article type: Article
Session ID: J0103-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
An image-based Excel worksheet is developed for thermal design of a vapor chamber. Excel VBA is introduced in this worksheet, where three-dimensional heat transfer simulation is performed by using a steady-state heat-conduction model of the vapor chamber. In this simulation, each cell is regarded as a control volume, and several worksheets are used to construct a three-dimensional grid system. Parameters are visually inputted into the worksheets, and the calculation is performed using a computer mouse. The calculated temperature is shown in the cells and then visualized by the Chart Wizard. The numerical results obtained by Excel simulation are compared with those by Fortran simulation to confirm the validity of the present numerical method. The Excel simulation is visual, easy and useful for the thermal design of the vapor chamber.
View full abstract
-
Tsuneyuki SASAKI, Koichi HIROSE, Takashi NAKAZAWA, Hirotoshi TERAO
Article type: Article
Session ID: J0103-3-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, downsizing of electronic equipment is promoted. Therefore, the situation that accumulates in the device heat sources and heated parts is made and has increased. So, thermal head which generates heat is arranged near other components inside compact thermal printer. In order to maintain higher print quality of thermal printer, it is necessary that temperature around the thermal head keep littler than prescribed temperature. This study reports about characteristic of temperature response of thermal head which use a thermal storage sheet. This is a basic study to eliminate cooling fan for cooling system in compact thermal printer.
View full abstract
-
Tetsuro OGUSHI, Hiroshi TAKEMURA, Yoshihide IMAMURA, Masakazu NAKANISH ...
Article type: Article
Session ID: J0103-3-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We tried experimentally to reduce the thermal contact resistance by using aluminum thin film under low contact pressure region from 10 to 1000 kPa. As the results of the experiment, the following conclusions were obtained. (1) In spite of binal interfacial surfaces, the aluminum thin films of O-temper and F-temper as filler materials showed 1.0〜1.5 times and 1.4〜2.0 times larger thermal contact conductance than the bare contact condition, respectively. It is due to the simultaneous effects of reduction of effective interfacial thickness and increase of real contact area ratio. (2) The aluminum thin films with vacuum pump oil or phase change sheets on the double surfaces of the film showed 4〜5 times and 4〜7 times larger thermal contact conductance than the bare contact condition, respectively. It is mainly due to the increase of the thermal conductivity of the interfacial material. (3) The experimental data were well correlated by using effective interfacial thickness and real contact area ratio.
View full abstract
-
Takehiro HASHIMOTO, Shinji NAKAGAWA, Masaru ISHIZUKA
Article type: Article
Session ID: J0103-4-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Fundamental thermal performance of a liquid cooling system for small electronic equipment has been studied. A liquid cooling system is attracting attention because an increase of heat generation density in electronic components requires effective cooling. The cooling system proposed in this study uses a Mini-tube and a Microencapsulated Phase Change Material (MEPCM). The coolant including the MEPCM with an average diameter of 3 μm was supplied into the Mini-tube having a diameter of 1 mm. The mass concentration of MEPCM was changed from 0 to 5 %. The increase of the MEPCM mass concentration reduces the temperature rise of the heated tube wall.
View full abstract
-
Makoto Shimizu, Hiroo Yugami
Article type: Article
Session ID: J0103-4-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes the new technique of cooling electronic devices packaged in resin. In recent years, cooling electronic devices becomes very serious problem. To enhance thermal radiation from electronic devices, this problem is improved because 20%-40% of heat is dissipated by radiative heat transfer. We report new technique about cooling electronic devices to control radiative spectra from its surface. Resin which packages an electronic device prevents radiation from going outside air. We consider that radiation from electronic devices transmits resin to control radiative spectra. As a result, cooling performance improved. A spectral selective emitter which consists of periodical micron meter scale two-dimensional grating on metal surface can control radiative spectra. In this research, we decide an optimal selective emitter design from simulation and fabricated it by micro-machining technology. Finally, the fact that using spectral selective emitter enhanced cooling performance is obtained from cooling performance test.
View full abstract
-
Takashi FUKUE, Tomoya SHIMOUCHI, Masaru ISHIZUKA, Shinji NAKAGAWA, Tom ...
Article type: Article
Session ID: J0103-4-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper describes air cooling performance for electronic circuit boards set in the thin enclosure, where cooling air flow pass is very narrowed by many mounted devices. Especially, we focused on the effects of various heat dissipation values from chips and the space on the board. To discuss the cooling performance in the thin enclosure, we designed a test enclosure model which is composed of a model cardboard including 5 heat sources and a heatsink duct and inspected a temperature rise of the model board and heat sources experimentally. From the result, it is found that we obtained a similar cooling performance regardless of different heat dissipation values and heat dissipation locations when we have the high thermal conductivity electronic boards and a heatsink on the board to dissipate the heat, even with narrow cooling flow pass on the board.
View full abstract
-
Hideyuki ISHIGAKI, Yuichi FUNAWATASHI
Article type: Article
Session ID: J0103-4-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Flow patterns and heat transfer characteristics of boiling two-phase flow of water in a flat microchannel have been experimentally examined. The test channel has a cross section of 0.5 x 10 mm^2 and a length of 162 mm. The heating section is set on the bottom wall at the middle of the channel. The length and width of the heating section are both 10mm. The boiling curves for two degrees of subcooling of about 25 and 55℃ are obtained. The video images of the flow recorded at 300 f/s reveals that a single vapor bubble grows in size both upstream and downstream staying on the heating surface and flows downstream at a time it gets large enough.
View full abstract
-
Masao Fujii
Article type: Article
Session ID: J0103-4-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Two rectangular block-like elements as an electronic module are positioned in a parallel-walled channel and cooled by forced convection airflow. A metal plate with holes as a barrier blocks the channel, which is intended to function as a cover for protecting them from mechanical or electromagnetic damage, or as a thermal control device. Per-module heat transfer coefficients in the presence of the barrier of various hole diameter d, porosity, and distance L, between the module and the barrier were measured. In the presence of the barrier with holes, the heat transfer coefficient at two modules was improved. Nusselt numbers are correlated as a function of Reynolds number, L/d and porosity.
View full abstract
-
Ryota GOTO, Shinji NAKAGAWA, Katsuhiro KOIZUMI, Masaru ISHIZUKA
Article type: Article
Session ID: J0103-5-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Flow soldering process is one of major soldering process used in the manufacture of electronics. One of the defects in soldering is a bridge, which connects adjacent components and results in a short circuit fault. It is necessary to clarify the conditions under which the bridge occurs. Flow soldering process with a simple model has been studied experimentally and numerically. The purpose of this study is to clarify the relation between the lifting velocity and the solder volume on the joint. As a result, simulation was able to reproduce a tendency similar to experiment on the relation between the lifting velocity and the solder volume.
View full abstract
-
Yusuke HIOKI, Masaru ISHIZUKA, Shinji NAKAGAWA, Tomoyuki HATAKEYAMA
Article type: Article
Session ID: J0103-5-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In recent years, natural cooling techniques become very important from the viewpoint of high reliability and noise control. In this study, to precisely predict the air temperature rise in the enclosure, we proposed two simple equations about the heat transfer on the outside wall and the inside wall. By using these equations, in which the effect of convection is separated from radiation, we considered the average convective heat transfer coefficient without the effect of radiation. We calculated the average heat transfer coefficient from the results of the experiment and the CFD analysis. As a result, the average heat transfer coefficient of outside wall obtained from proposed equation with experimental results showed good agreement with that from CFD analysis. However, the average heat transfer coefficient of inside wall with experimental results and that from CFD analysis showed different values. This difference seems to be caused by inappropriate model of radiation in our proposed equation about inside wall.
View full abstract
-
Yasushi NISHINO, Masaru ISHIZUKA, Shinji NAKAGAWA, Tomoyuki HATAKEYAMA
Article type: Article
Session ID: J0103-5-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The natural cooling capability and flow field in relatively small electronic equipment were studied by numerical simulation. A vertical multi-channel model was used as an numerical model of electronic equipment. The multi-channel is an idea of natural cooling enhancement. The multi-channel model is constructed with two copper walls simulated the printed circuit boards, two acrylic walls simulated casing walls and four partitions. The multi-channel model has five ducts with 2mm thick copper partitions between two copper walls. The clearance between the copper walls is varied from 5 mm to 15 mm. The velocity profiles and temperature rise of air in the channel and temperature of the copper walls were obtained and the availability of multi-channel structure is discussed.
View full abstract
-
Takayuki KITA, Yuichi FUNAWATASHI
Article type: Article
Session ID: J0103-5-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Two dimensional numerical simulations are conducted to investigate the heat transfer in a square cavity where a heat source of a constant and uniform temperature is located on the middle of a vertical side wall, the other side wall is kept isothermal at the temperature lower than that of the heat source, the rest of the wall is adiabatic and an adiabatic object is located inside. It has been found that the heat transfer is enhanced at certain values of the height of the object. It has been also found that in the cases where the flow pattern between the heater and the object resembles the one in the channel between parallel plates, the heat transfer characteristics are well correlated by using modified Nusselt and Grashof numbers.
View full abstract
-
Seiichiro Morizawa, Koji Shimoyama, Shinkyu Jeong, Shigeru Obayashi
Article type: Article
Session ID: J0104-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A hard disk drive (HDD) involves high-speed trailing flow on the rotating disk, which may cause vibration force. In order to reveal the information of flow fields related to the vibration force, this study performed the data mining in the unsteady computational fluid dynamics (CFD) simulation data for HDD flow fields. The present data mining started from the extraction of temporal characteristics from the time-series data of fluid properties given at each grid point, and then moved to the clustering analysis of the grid points based on the similarity of the temporal characteristics. Finally, the clustering results were projected onto a real space of the HDD for discussion. The present results indicated that a significant sequence of flow energy production and dissipation, which leads the vibration force, occurs near the filter entrance, arm root, and shroud wall between them.
View full abstract
-
Hiroyuki FURUKAWA, Gou TANAKA
Article type: Article
Session ID: J0104-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In previous studies of a flow caused by a rotating disk in a casing, the geometry of a rotating disk is not considered significantly. Recent studies unveil that a gap of radial direction has a great influence on a flow between a casing base and rotating disks. In this study, the effect of a gap in the radial direction on the flow near the fixed disk was investigated using seven different rotating disks to change the gap size of the cylinder casing. As a result, it has been observed that "bead-like vortex" is generated in one of seven disks. "Bead-like vortex" is investigated in detail and the result of the experiment is shown in this paper.
View full abstract
