Numerical results of HPC simulation that investigate the aerodynamics and the assessment of the running stability of road vehicles are presented in this study. FrontFlow/red-HPC is utilized to predict the flow around road vehicles. This code is based on the open source CFD software FrontFlow/red, and is developed specifically for road vehicle aerodynamics under HPC environments. Two applications of the CFD code are shown in this paper. One is the modal analysis for flow structures which cause the fluctuating lift in the range of below 5Hz. This frequency range is close to the natural frequency of the vehicle’s suspension and damper system, and it may cause resonance. Dynamic Mode Decomposition is used to extract the flow structures oscillating in the specific frequency. The results indicated that the flow around the rear trunk-deck and rear underbody contributed to the fluctuating lift. The other shows the need for a two-way coupled simulation of the unsteady aerodynamics and the vehicle motion. A commercial motion solver is coupled with FrontFlow/red-HPC in the coupled simulation framework. This framework is applied to predict the vehicle’s trajectory when vehicles are subjected to gusty crosswinds. Then, the results of the conventional one-way coupled simulation and two-way coupled simulation are compared to investigate the validity of this coupled framework.

Large scale structures such as bridges, ships, aircraft are served for a long time. Fatigue cracks can be generated in some parts of the structures. When cracks are small, the stress distribution around the crack does not affect entire the structure. However, large deformation and function loss of structures are largely induced by breaking portions after crack propagation. On the other hand, it is important to grasp the crack propagation behavior for safety purpose until repairing because arrangement of the repairing may take a long time. This paper shows some case studies of crack propagation analysis evaluation for stress intensity factors and crack trajectories for some portions of large structures by the Code_aster's X-FEM function. Code_Aster is open-source software for mainly structual and thermal analysis.

In order to improve reliability of ICT equipment, there are a lot of items to clarify the complex behavior from thermal, structural and electrical fields. In this section, for solving such problems, it is introduced case-study and simulation system which are aimed accuracy and efficiency, about utilization of combinatorial and multi-physics simulation.

Legal issues relating to self-driving cars are presented and discussed through a mock trial. An accident that occurred some years ago has been modified to present issues that might be tried before a court in the future. Two important laws that are relevant to traffic accidents and defective products are discussed. One is the Act on Compensation of Damages Caused by Car Accidents and the other is the Act on Product Liability. To simplify the issues the mock trial is focused especially on the product liability. Expert witnesses are examined and the court decides whether the accident has been inevitable or caused by either malfunction or defective design.

Mitsubishi Hitachi Power Systems, Ltd. (MHPS) was established by merging the thermal power generation business sectors of the two companies: Mitsubishi Heavy Industries, Ltd. (MHI) and Hitachi, Ltd. (HITACHI). Both companies had separately pursued technologies for the effective and clean utilization of coal by employing their own firing systems. In addition to their business histories regarding the development of such technologies and the latest technological trends, such as USC and IGCC, this report also addresses our future direction as MHPS in the development of boiler

A on-site hydrogen refueling station (HRS) with the capacity of 300 kg (3,300 Nm3) H2 production per day for fuel cell vehicle (FCV) was installed in a wastewater treatment plant (WTP) in Fukuoka city, Japan and operated around one year. The hydrogen was produced by the steam reforming of methane in biogas which generated from anaerobic digestion of sewage sludge. Membrane separation of methane from biogas and PSA separation for purifying the reformed gas were also implemented. Despite of the fluctuation of biogas quality including the methane concentration, the hydrogen quality is satisfied with ISO 14687-2 standard. The impurities in biogas such as siloxane and high boiling point hydrocarbons were removed by activated carbon and no significant damage was observed. This is the world first report of long continuous operation result of on-site HRS from biogas.

In our environmental solutions section, we have developed a wide environment solution business centering on the waste gasification and melting technology, and could achieve some positive results in recycling-based society and the prevention of global warming. In this paper, we report the features of the shaft-furnace type direct melting system, the stoker-type incinerator of Steinmüller Babcock Environment GmbH of Germany, and sewage sludge fuelization by J-COMBI^® system, which are our typical environmental equipment.

This study examines the result of internship program which provides university students to learn engineering ethics through experience by cooperating with company workers with disabilities to improve production process, manufacturing tools and work place layout into design with universal concept. This program provided interns opportunities to understand how Normalization concept can be realized in workplace, and to motivate them working for attaining it through experience of working with them, assembling operation, finding problems and making resolution idea in this two-weeks program since 2012. They learned how important that viewpoint of technology user with disability to be concerned for developing suggestion of improvement, and found themselves had vague prejudice against those working people. And they became aware of engineer's role in building condition where people with and without disability work together. For better program, we need to install evaluation method on the interns' learning process and results attained, and to appraise effectiveness of suggested improvement by interns in the workplace to verify validity of learning process in this program.

In Japan, about half of country is occupied by heavy snowfall area. Snowblowers are essential for people who live in such area. For the efficient development of a snowblower, stable and quantitative performance evaluation method is required. Presently, performance of a snowblower is mostly investigated by manipulation with an actual machine in heavy snowfall area. However, the snow removal work using an actual machine can evaluate only qualitative performance and it is required to confirm the performance in several regions because snow properties fluctuate according to a change of climate or region. Therefore, we tried to reproduce the snow removal work using the Discrete Element Method (DEM) in this study. DEM is widely used as an effective method in granular flow, powder mechanics, rock mechanics and simple snow behavior in a snowblower. In addition to the conventional DEM, we developed potential model for reproducing the compaction of snow and air drag model in order to consider the properties of actual snow. Moreover, we constrained the degrees of the freedom of snow elements to reproduce the initial shape of fallen snow in the simulation. As a result of this computational method, it was clarified that the detailed snow behavior in relation to the snowblower can be successfully reproduced by simulation using the DEM. The calculation results were compared with the experimental results, both results exhibited reasonable agreements. Therefore, we have succeeded in the computational reproduction of snow behavior in a snowblower using the DEM with new snow property model.

Si power devices are used in various places such as home & office, power plant, transportation and industry. The devices consume much electrical energy at conversion of the currency and voltage. And then the efficiency of the devices has been improved for a long time in order to reduce the consumption of the energy. However the efficiency of Si semiconductor will have reached to the theoretical limitation in the near future, but the operating temperature and frequency have to been increased higher in order to improve the efficiency of electrical conversion. Therefore WBG semiconductors such as SiC and GaN with many benefits to save energy are expected as the next generation of Si semiconductors. In this study, the quality and reliability for die bonding at low cost Ag sintering paste were researched. The Ag flakes start to sinter above near 200°C and almost finish to sinter at 250°C. It was revealed that the die bonding strength of samples with Ag flake paste more stable than Ag nanoparticles paste after being subjected to 1000cycles at temperature range of -40 to -180°C.

This paper focused on crystal growth of pure silicon for high power devices. This paper focuses on how silicon is contaminated by carbon and oxygen during crystal growth. Then, we discuss other origin of lifetime degradation as well as light elements such as oxygen and carbon incorporated in silicon crystals.

This paper describes the methodology for reliability evaluation of power semiconductor devices. When they are used in power systems, they are subjected to thermal cycles caused by power fluctuations. In such circumstances, power modules break down because of wire-liftoff in wire-bond and solder crack in dye-bond induced by thermal fatigue. In most papers concerning power electronics, such thermal fatigue life N_f has been related with temperature range ΔT together with the mean temperature T_m during cycling. The N_f -ΔT relation depends on the dimensions of power modules, even if they are made of the same materials. On the other hand, the Manson-Coffin rule correlating N_f with inelastic strain range Δε_in or inelastic strain energy density ΔW_in is independent of the dimensions of power modules. This paper presents how to obtain the Manson-Coffin rule from thermal fatigue experiments of power modules. In addition to the mechanical reliability problems described above, the present paper describes the importance of an electrical reliability problem of power devices, in which the electronic performance of semiconductor power devices is adversely affected by the action of stress.

Power modulues such as the electronic packaging structures are composed of various components which have different coefficient of thermal expansion (CTE). An accurate thermal strain measurement is needed to evaluate strength of the structures because thermal stress and strain occurs due to the CTE mismatch of components. In this study, a high accuracy DIC method for eliminating the periodical measurement error is applied to measuring thermal starin of electric packaging structure, and evaluated the validity and efficacy of this method. As a result, the periodical error in the measured thermal strain due to the CTE mismatch can be eliminated. Thereby measurement accuracy is improved and the precise thermal strain distributions can be observed. Therefore, this method is effective for thermal strain measurement of electronic packaging structures.

Wind power is one of the remarkable energy effective utilization system and early known as practical use. Recently, development of wind farms which place several wind power plants in the same area are planning. The design process become more larger and complicated. Therefore it needs system verification by simulation instead of experimental only. One dimensional (1D) simulation is one of a suitable method for system simulation. It can express each function, and facilitate modeling of system. On the other hand, it needs three dimensional (3D) simulation to get characteristics of lifting force of wind turbine using CFD. However 3D simulation is not suitable for system simulation due to large calculation time and cost. In this paper, we described 1D/3D cooperative simulation approach for wind power generation system.

It is necessary to use multiphysics analysis approach to investigate numerically the way how to get renewable energy and its transformation to electric power through energy harvesting techniques. In this article, we review COMSOL Multiphysics, commercial finite-element analysis software, and its application examples in renewable energy and energy harvesting. As a result, it is found that COMSOL Multiphysics is very applicable in solving various scientific problems, where there are many strong couplings such as fluid-structure interaction, structure-acoustic interaction, electromechanical coupling. For thermoelectric conversion, it is observed that COMSOL Multiphysics provides for PDE interface in order to implement the user's defined equations. Piezoelectric harvesting example is introduced to verify the ease in use of GUI of COMSOL Multiphysics.

A devlopment of the movable flap gate type breakwater, which is based on a steel flap gate in hydraulic gates with a number of adoption results, is reaching the final stage of demonstration tests in the sea.The flap gate type breakwater usually lies down on a seabed and rises up through a sea surface with buoyancy when tsunami or storm surge occurs. In past studies reflected viewpoints of a large number of specialists, it has been confirmed that the flap gate type breakwater has capabilities against tsunamis. This paper describes the characteristics of the flap gate type breakwater, the expansion of utilizations in seawalls except breakwaters for tsunami and storm surge reduction.

To measure the deformation of the structural material, the Moire method has been used for the full-field deformation measurements. However, in this method, two (master and model) grids or gratings should be overlapped on the specimen. To avoid this problem, a Moiré method using digital camera has been applied. The model grid was fabricated on the structural material, and shooting by a digital camera. Using an image processing system, the Moiré fringe can be observed. Using this method, the deformation of the structural material such as strain distribution, displacement, and vibration of the structural material can be measured. The damage of the structural material can be estimated.

In the fields of materials science and engineering, there are growing demands for monitoring temperature and its distribution of heated materials and structures. This is basically because temperature is one of the most important factors that dominate the material properties and behavior. Such temperature monitoring is often required for not only the inside of heated materials but also the interface between different media. Recently, a new ultrasonic method, so-called ultrasonic thermometry, providing such temperature monitoring has been developed. The method basically consists of ultrasonic pulse-echo measurements and an inverse analysis for determining one dimensional temperature distributions. In this presentation, recent progresses in the ultrasonic thermometry and its application to temperature measurements of heated materials are presented. In particular, temperature measurements at an interface between two materials are highlighted. Some topics on in-situ measurements of temperature at a friction surface and heat flux though a solid interface are also reported. It is expected that the ultrasonic thermometry could be a useful means for in-situ or on-line monitoring of transient temperature variations of materials processed at high temperatures.

In nature, there are a lot of functional anisotropic surface structures, such as drag reduction surface of shark skin. And these structures are formed by self-organization processes. For preparations of biomimetic anisotropic self-organized structures, wrinkle structures are suitable. Wrinkle structures are formed at the hard surface thin layer fixed on soft substrates when in-plane stress is applied. One of the characteristic properties of wrinkled surfaces is their shape-tunability in response to changes in the applied strain. However, the adhesion between the elastic hard thin layer and the soft substrate often cannot withstand the internal stress associated with the formation of wrinkles, leading to partial delamination known as buckling delamination. In this report, we show a fabrication of durable micro wrinkle structures by using self-organized honeycomb-patterned porous polymer films as embedded hard layers. We prepared honeycomb-patterned porous polymer films with polystyrene by breath figure method. After UV-O₃ treatment, honeycomb-patterned films were fixed upside down to glass substrate with poly(styrene-co-allyl alcohol) as adhesive. After peeling off the bottom layer of the films by an adhesive tape, the fixed top layer on the glass substrate was turned upside down in ethanol, and put on a glass substrate. Poly(dimethylsiloxane) (PDMS) precursor mixed with the catalyst was poured into the top layer, and cross-linked by heat treatment (80 oC, 3h). And then, the porous network structure embedded in the PDMS substrate was obtained. By applying in-plane strain, successfully micro wrinkle structures were formed repeatedly. However, wrinkle periods were depended on periodicity of honeycomb-patterned films. To control the wrinkle period, aluminum was sputtered on the only top of honeycomb-patterned films before dividing into top and bottom layers. After that, same embedding processes were carried out. As a result, wrinkle structures were also formed, and wrinkle periods can be controlled by thickness of aluminum layers.

This paper reports optical read-out thermal imaging devices based on IR-to-visible conversion technique using temperature sensitive phosphor (Eu(TTA)₃). Infrared emit from the observation object induces temperature change of a thermally isolated microstructure, of which the temperature can be read out by the luminescence intensity of Eu(TTA)₃. Two types of imaging devices were fabricated and evaluated, one of which was made of vacuum deposited Eu(TTA)₃ on a deep reactive ion etched thermal isolation structure, and the other was made using photo-patternable temperature sensitive paint combined with a transfer method. Both device can detect the temperature distribution, however the device using vacuum deposited Eu(TTA)₃ had a better performance which can detect a human.

Advanced visualization analysis in electrostatic multiphase flow as in ionic liquid electrospray for space thruster or electrostatic control of cellulose fibril flow for high strength and high elastic cellulose material synthesis has been introduced. A detail analysis of ionic liquid electrospray formation has been conducted by high speed imaging, clarifying the relation between ejected droplet velocity and diameter. Furthermore, the transient behavior of cellulose fibril flow by applying AC electric field has been shown. Fibrils are successfully aligned in parallel to the electric field. The fibril alignment degree was quantitatively evaluated using optical characteristics of cellulose fibril.

We propose a novel technique to drive turbulent mixing of a fluid confined in a smooth container. It is a weak precession of the container that can lead to strong turbulence of the confined fluid. By our extensive laboratory experiments and direct numerical simulations, we have revealed that the optimal rate of precession for the fastest mixing is about ten percent of the spin, and that symmetric containers such as a sphere are much better at sustaining turbulence than asymmetric ones. Only about ten spins are required to complete the mixing in a precessing sphere with precession rate being about 0.09-0.1.

The mean velocity profile and the friction factor was measured at high Reynolds number using high Reynolds number actual flow facility (Hi-Reff) at NMIJ, AIST. The Reynolds number range of this experiment is from Re_D=1.2×10⁴ to 1.8×10⁷. The Karman and additive constants of the mean velocity profile have the Reynolds number dependency for Re_D<5.0×10⁵ and they are constant for Re_D>5.0×10⁵. The Karman constants obtained from the velocity profile measurement and the friction factor measurement are completely consistent, which is 0.383, for Re_D>5.0×10⁵.

When a liquid droplet impacts a hot solid surface, enough vapor may be generated under it to prevent its contact with the solid. The minimum solid temperature for this so-called Leidenfrost effect to occur is termed the Leidenfrost temperature, or the dynamic Leidenfrost temperature when the droplet velocity is non-negligible. We observe the wetting or drying and the levitation dynamics of the droplet impacting on an (isothermal) smooth sapphire or a (non-isothermal) glass surface using high-speed frustrated total internal reflection imaging, which enables us to observe the droplet base up to about 100 nm above the substrate surface. By this method we are able to reveal the processes responsible for the transitional regime between the fully wetting and the fully levitated droplet as the solid temperature increases, thus shedding light on the characteristic time and length scales setting the dynamic Leidenfrost temperature for droplet impact on the substrates.