We present advances in the Particle Finite Element Method (PFEM) for solving multidisciplinary problems in fluid and solid mechanics accounting for fluid-structure interaction (FSI), thermal coupling and free surface effects. The PFEM uses an updated Lagrangian description to follow the motion of nodes (particles) in the fluid and the structure domains. Nodes can freely move and separate from the main analysis domain representing, for instance, the effect of water drops. A mesh connects the nodes defining the discretized domain where the governing equations are solved with the FEM. An iterative scheme for solving the non linear transient FSI problem is used. The PFEM allows to treat frictional contact and surface wear at fluid-solid and solid-solid interfaces via mesh generation. We present applications of the PFEM to study the effect of waves on harbour and marine structures, the motion of bodies in water, bed erosion in channel flows and burning of objects.

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In recent years. tailor-made medicine which cives the best treatment for individuals attracts much attention. Novel techniques for reading DNA base sequences at high speed are required to replace the conventional methods with more efficient ones. In a recent report. it was suggested that a nano-scaled particle in the electrophoretic flow could be detected with nano-scaled electrodes. This is a first step to develop a novel technique in which DNA sequences can be read more efficiently. In the present stud', the detailed mechanism of detecting a nano-particle with nano-electrodes is theoretically discussed A theoretical model is developed from the viewpoint of molecular dynamics and electric circuits. Consequently, it is confirmed that the theoretical result successfully explains the experimental one of result as response mechanisms.

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Li-ion chargeable batteries are widely used for many portable devices. In recent years, markets of Li-ion battery have grown rapidly due to expansion of electric vehicles (EVs). The importance of improvements in its capacitance. energy efficiency, and reliability are reconsidered. We have studied to construct analytical models of Li-ion battery which well predict experimental results. In charge and discharge processes, interacting with surroundings, Li^+ ions and anions flow through three regions: the electrodes, the separator, and the electrolyte. However, this mechanism is not clarified in detail due to complexity of the materials and the flow dynamics. In particular, stable solvation shells which prevent fluent flows of Li^+ ions are considered to cause the mobility reduction. In this study, we cany out molecular dynamics analyses to investigate the diffusivity of Li^+ ions in electrolyte, focusing on the solvation number of Li^+ ions. The diffusion coefficient is discussed as a ftinction of salt concentrations. Consequently, it is found that the behavior of solvent molecules which form solvation shells around Li^+ ion is very effective to the diffiusivity of solvation structures.

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High-end computers such as T2K or the K computer requires hybrid parallel programming model because of their hierarchical hardware architecture. Conjugate gradient solver in a MPI parallel structural analysis application FrontISTR that invokes HEC-MW is parallelized in a MPI-OpenMP hybrid way. In the current implementation, 1.5 - 3.0 x speedup in SpMV operations and 1.5 x speedup in actual preconditioned CG solver have been achieved.

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Since General structural analysis program like NASTRAN(NASA Structural Analysis Program)[1] performs 'Out-of-Core' method, it is required to configure highly balanced system with CPU performance , memory bandwidth and I/O capability to realize high-performance computing. The Watson Sparse Matrix Package,WSMP[2][3] ,is a software package for solving linear equations which has being developed by IBM Watson Research Center . WSMP enables to solve large scale sparse matrices to achieve robust and outstanding performance using 'In-Core' method. This paper describes techniques how to apply WSMP to ISV(Independent Software Vendor) package software exemplified by NASTRAN and also describes it enables to modify program characteristics to realize performance improvement. Many CAE(Computer Aided Engineering) software including NSTARAN provide functionality of external user interface that allows users to encapsulates matrices solving part. That is , internal matrices are possible to solve with combination of the user interface and user program written by FORTRAN andlor c. As the result of applying this methodology, it enable simple system configuration for NASTRAN. Also it is possible to improve total elapsed time by eliminating I/O requests and fully utilized parallel processing capability.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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This paper deals with a large-scale 3D non-linear magnetostatic analysis using the Domain Decomposition Method (DDM). As part of the challenge, a high performance parallel computing on the non-linear magnetostatic problem with 100 million degrees of freedom is performed.

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The Balancing Neumann-Neumann preconditioner is well-believed to be efficient to speed up the convergence. However, this method faces a difficulty of the coarse problem: with an increase in Degrees of Freedom (DOF), the size of the coarse problem increases accordingly and becomes difficult to solve eventually. To overcome this, an Incomplete Balancing Domain Decomposition (IBDD) preconditioner is developed in this work. The algorithm is implemented in parallel by the Hierarchical Domain Decomposition Method (HDDM), and it is feasible to solve large scale models of over 100 millions DOF.

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Presence of dissolved atomic hydrogen in metals and alloys can severely degrade mechanical properties and fracture toughness, reduce the fracture strength and accelerate the crack growth. During hydrogen embrittlement, materials soften at microscale due to the enhancing of dislocation mobility. In this work, we conduct a coupled hydrogen diffusion-elastoplastic analysis which includes the effect of hydrogen on materials softening in microscale by taking into account a well developed constitutive equation accompanied by considering the reduction in the local flow stress upon hydrogen dissolution into the lattice. Progress has been made in that a new module has been developed, which makes the open source code ADVENTURE-Solid software be capable of specific simulation for hydrogen-plasticity interactions.

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[in Japanese]

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Cytokinesis is the final process of cell division, in which a cell body is mechanically separated into two daughter cells. The changes in cell shape are regulated by not only the actomyosin contractile ring but also global cell-surface mechanics whose properties are predominantly provided from cytoskeleton. The spatial and temporal dynamics of cell-surface mechanics and its underlying regulatory mechanisms, however, are not well understood. It is technically difficult to directly measure cell-surface mechanical parameters with high spatio-temporal resolution. Here, we are trying to construct an indirect method for predicting the spatio-temporal dynamics of the mechanical parameters in which experimentally observed cell shapes and mathematical models are employed. By using this method, we are predicting spatio-temporal change in bending modulus, an index of cell-surface stiffness. We will also discuss the application of this method for illuminating the mechanisms conferring morphological phenotypes in various cvtokinesis mutant cells.

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A simple and practical VOF (volume-of-fluid) method is proposed, based on a continuous approach. A profile of the VOF function is approximated by a hyperbolic tangent function which is smoothly distributed across the transition region. A continuous approach with a smoothed interface avoids a difficulty to calculate the derivative values of the VOF function due to its discontinuity. Moreover, the analytical or numerical integration is able to be adopted in a flux calculation that enables a coding with a few IF-THEN types of conditional statements even if the interface is given as a curved surface. In this research, a validation test in the advection equation is carried out, moreover in the Navier-Stokes equations, a single rising-bubble problem is performed.

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A lattice Boltzrnann model with a multiple-relaxation-time collision operator for the convection-diffusion equation is presented. The proposed relaxation-time matrix with off-diagonal components enables us to take into account full anisotropy of diffusion. An asymptotic analysis of the model equation is carried out to show that the model is second-order accurate in space. The applicability to the anisot.ropic diffusion is also demonstrated by means of some numerical examples.

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To investigate turbulent combustion phenomena in a gas-turbine combustor. we conduct a numerical simulation of a partially premixed turbulent combustion in a practical combustor. Large-Eddy simulation and 2-scalar flamelet approach are coupled and applied to the unsteady turbulent combustion simulation in the combustor geometry for modeling turbulent and combustion reaction phenomena, and also their interactions. This paper reports an application of the LES to practical gasturbine combustors and discusses their feasibility to the practical combustor design, especially for NOx production.

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In order to understand fundamentals of fluid dynamics, it is important to utilize both of CFD and EFD. However, CFD and EFD analysis supplement it in a true meaning, and it is doubt whether we get a good result by synergy. In this study, we make use of an advantage of wind tunnel experiments and numerical analysis and introduce the example that built a prediction model of aerodynamic sound radiated from a rearview mirror. First, we pointed out problems of a conventional theory with experimental results, and next, we constructed a physics model from the results of numerical analysis. Furthermore, we determined the dominant parameter of noise generation by the data which we cannot measure by the wind tunnel experiments, it provided by result of CFD. The empirical constant is unnecessary in a suggested model. Therefore, the suggested model was a more essential prediction model.

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