The present study deals with the flow between co-rotating disks, namely, the disks which rotate co-axially in the same direction at the same angular velocity, with a narrow gap enclosed by a stationary shroud at their circumferences. The flow often accompanies azimuthally-fluctuating instabilities: a non-axisymmetric secondary flow nears the shroud. In the experiments, we use a high-speed video camera and a YAG laser, visualize the flow in the axial midplane and the meridional plane between the co-rotating disks and carry out the particle image velocimetry (PIV) analysis. The torus-vortex modes are defined. In numerical calculations, the authors confirm the experimental results. Based on such PIV results, the authors define experimentally and numerically the flow torus-vortex modes in addition to core-shape modes, and reveal the details of the flow structure in each mode.

In recent years, 3D-clearance analysis is used in the manufacturing industry. By using the clearance analysis, we can check the interference between the components. On the other hand, many products have been reduced in thickness for lightweight and cost reduction, so we have to check deformation of a product at the time of assembly of components. But it was too difficult for us to check deformation at the time of assembling because clearance analysis cannot express the deformation. In this paper, we show the way to combine clearance analysis with FEM analysis by quality engineering.

In this paper, we describe a practical fluid volume-mesh generation techniques for the Isogeometric Analysis (IGA). The space–time slip-interface (ST-SI) method can be applicable NURBS descritization in space and time, however a good mesh generation for fluid is not trivial. In this paper we use the existing techniques for mutli-block structured mesh technique and projection techniques to generate fluid volume mesh. The ST-SI method allows having C⁻¹ descritization without loosing accuracy. This diminisies the knot restriction between NURBS patches. The paper includes examples and how to control the mesh resolution and qualities, and test computations with the ST method.

In this study, the creep behavior of ultrafine plate-fin structures which possess uncertainty factors in material properties of a base metal and shapes are investigated using the Monte Carlo simulation. For this, a time-dependent homogenization theory is applied to the analysis of creep behavior of ultrafine plate-fin structures. Moreover, Stepwise Limited Sampling (SLS) is introduced into the Monte Carlo simulation to reduce computational costs. Then, using the present analysis method, the effects of uncertainty factors on the creep behavior of ultrafine plate-fin structures subjected to a macroscopic constant stress at high temperature are investigated. This enables us to obtain tail probability values of creep strain by one tenth of computational costs compared to the conventional Monte Carlo simulation.

In this study, a multiscale damage simulation of woven composites with various weaving structures is conducted based on a homogenization theory. For this, the homogenization theory is reconstructed for 2×2 twill-woven laminate and 5H satin-woven laminates. The Hoffman's failure criterion is then introduced into the theory to determine the failure of fiber bundles and a matrix material, and the damage modes. The damages are expressed as reduction of stiffness according to the damage modes. The present method can efficiently analyze the macroscopic strength and the microscopic damage development of woven composites. This method is then applied to the damage simulation of plain/twill/satin-woven E-glass/vinylester laminates under on-axis uniaxial tension. It is shown that the weaving structures affect the macroscopic strength of the laminates, which is attributable to the difference in the microscopic damage development in the laminates depending on the weaving structures.