Norihiko Nonaka

Technique for checking design rules for three-dimensional CAD data

A technique was developed for checking whether three-dimensional CAD shape satisfies design rules. Many design rules related to reliability and manufacturability should be considered in the design stage. Our technique automatically recognizes feature shapes such as a rib and boss from a CAD model shape, and it checks the shape and arrangement. The effectiveness of the technique was demonstrated in a test of the injection-molded part.

DEVELOPMENT OF A NEW SIMULATION-BASED PLATFORM FOR PRODUCT AND SERVICE CUSTOMER CO-DESIGN USING AI

This paper describes our new simulation-based platform for the customer co-design of products and service. This platform is based on the concept model that builds integrated digital models from the real world and analyzes from the simulation results. It explores and maximizes customer value using machine learning algorithms. The platform consists of a workflow constructor and a GUI builder with reusable nodes and templates. An example is given in the oil & gas filed. The customer co-design GUI is built in 5 minutes and can be used to assess the business feasibility of the oil & gas devices.

Immersed Boundary Method for CFD Analysis of Moving Boundary Problems in OpenFOAM

CFD simulation of hydraulic equipments involving moving boundary components is really challenging due to difficulty in maintaining a good quality mesh essential for obtaining accurate numerical solutions. To deal with these problems, commercial codes such as Ansys CFX provide the option of mesh morphing which must be used in conjunction with pre-defined multiple grid configurations to account for changing flow domain. In contrast to this approach, immersed boundary method (IBM) provides an attractive alternative in which the complex moving surface is immersed in a fixed Cartesian (or polyhedral) grid. We have developed an immersed boundary simulation tool-kit for moving boundary problems based on OpenFOAM. It requires the user to provide the definition of the immersed surfaces in STL (stereolithography) format, type of flow (internal/external) and motion (stationary, pre-defined or flow-induced) of the surface. Numerical simulations have been performed for selected test cases to assess the computational performance of the immersed boundary too-kit. Numerical results of flow over stationary as well as vibrating cylinders agree very well with available experimental and numerical results, and show that the immersed boundary simulations accurately capture the vortex shedding frequency and vortical structures for moving boundary problems.Copyright

An Automatic Technique for CAE Analysis With a 3D-CAD Model

A CAE (computer-aided engineering) analysis system, consisting of a 3D-CAD (three-dimensional computer-aided design) modeler, a pre-processor, an analysis solver, and a post-processor, was developed. This system uses automated procedures for solid modeling, definition of analysis models (i.e., defining boundary conditions and material properties, traditionally done manually), mesh generation, numerical simulation, and visualization of results. The CAE analysis system has two key features: it can greatly reduce the analysis time, and it uses a 3D-CAD model as the geometric model for numerical analysis. It was found that the developed automatic system reduces the analysis time by 50% compared with that for manual operation.Copyright