Study on Numerical Simulation of Flow around Body by MPS using Cluster System

本研究将现有的二维粒子法程序修改为三维粒子法程序，并与实验结果和其他数值计算结果进行了比较，得到了较好的结果。通过展示本研究的各种数值计算结果，可以判断能够适应粒子法的流体现象。(1)用这种方法模拟了三维平板突然运动的一种过渡流体现象。结果表明，快速现象可以用MPS来计算。(2)落物撞击水面时的喷雾现象。并模拟了与水面碰撞时瞬间产生的喷雾现象。结果表明，与用高速相机拍摄的实验照片相比，具有较高的精度。(3)水面与落物碰撞后的运动六面体对角释放，模拟了落水到水面的过程和之后的运动。(4)简单形状的三维旋转翼利用旋转翼的六面体进行了三维旋转翼的基本计算，虽然质点方法很难将旋转翼按节距改变为有节距的形状，但可以得到物理上的正确性。

An existing two-dimensional particle method program was originally changed to the three-dimensional particle method code by this research, and an excellent result was obtained about the following three-dimensional flow compared with the experiment result and other numerical calculation results.The fluid phenomenon that was able to adjust to the particle method could be judged by showing a variety of numerical calculation results of this research.(1)Flow analysis around 3-dimensional plate that moved suddenlyA transitional fluid phenomenon was simulated by this method.As a result, it was clear that rapid phenomenon can be calculated by MPS.(2)Spray phenomenon when surface of the water collides by falling objectA triangular pillar was dropped, and the spray phenomenon momentarily generated when colliding with the surface of the water was simulated.As a result, the agreement with high accuracy could be seen compared with the experimental photograph with a high-speed camera.(3)Movement after surface of the water collides of falling objectThe hexahedron was diagonally discharged, and the fall to the surface of the water and the movement afterwards were simulated.As a result, a qualitative agreement was seen compared with the experiment result with the object with shape that looked like the hexahedron.(4)Three-dimensional rotational wings with simple shapeA basic calculation of the three-dimensional rotation wing was executed by using the hexahedron for the wing of the rotational wing.Physical validity could be obtained by changing to the shape with pitch from original shape without pitch although it was difficult to model the rotational wings with the pitch in the particle method.