[in Japanese]

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In present research, a convection scheme for incompressible flows simulation by particle methods is presented. This scheme convects particles to new positions, and do an interpolation of physical quantities, e.g. velocity, using a novel upwind moving least square scheme. The present methodology shows four basic advantages over conventional particle approaches: no particle clustering, less numerical diffusion, and enhanced numerical stability allowing the use of large time steps. The methodology is combined with least square moving particle semi-implicit method (LSMPS) and tested by solving lid-driven cavity flow problems with Reynold numbers ranging from 400 to 5000. The result is compared qualitatively and quantitatively with similar approaches proposed before, like particle shifting and Meshless Advection using Flow-directional Local-grid (MAFL).

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[in Japanese]

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We developed a new boundary condition of constant pressure for an inlet and outlet of a particle method. This allows us to generate fluid particles at an inlet boundary and delete fluid particles at an outlet boundary where pressures are fixed. The positions of generating particles were determined by the steepest descent method and virtual cells. Dirichlet boundary condition was given to boundary particles indirectly by considering virtual particles. We simulated Poiseuille flows under various cases by using the developed boundary condition, and compared the simulated flow velocities with theoretical values. As a result, the flow velocities were close to the theoretical values, and the efficiency of the developed boundary condition was shown.

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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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[in Japanese]

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In this study, we propose a hybrid numerical method for the predictions of the solidification patterns formed through the growth of multiples dendrites under melt convection. The proposed method is a combination of the multi-phase-field method for dendrite growth and the lattice Boltzmann method for predicting the melt flow. Important aspects such as the no-slip boundary conditions at the liquid-solid interface and the movement of the solid phase are taken into account by appropriately including additional terms in the formulation of the method. The effects of the solid motion and the melt flow on the solidification patterns are investigated in some detail.

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[in Japanese]

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