Yuzuru Eguchi

A conjugate-residual-FEM for incompressible viscous flow analysis

The application of the conjugate residual method to the indefinite system resulting from the finite element approximation of the incompressible Navier-Stokes equations is studied. The possibility to use an element-by-element preconditioner for the acceleration of the convergence is also discussed. With this scheme, one can achieve significant savings in storage without ever forming the large total matrix. Furthermore, the hybrid finite element mesh, a mixture of the structured and unstructured mesh subdivisions, is employed to minimize the storage requirement. The numerical simulations of the Karman vortex street, a driven cavity flow and the flow in a safety valve are presented to demonstrate the applicability of the proposed strategies.

A large-scale three-dimensional finite element analysis of incompressible viscous fluid flow

An efficient finite element scheme for large-scale three-dimensional flow analysis is proposed. Focus of attention is placed on the time integration algorithm and some techniques for the reduction of the storage requirement, including the one-point quadrature technique and an iterative matrix solver. Application to large-scale three-dimensional problems is given to demonstrate the feasibility of the proposed scheme.

Interactive postprocessor and animation system using a microcomputer

This paper is concerned with the development of a microcomputer-aided graphic system. In this system the difficult task of computation for graphical representation is carried out on a large computer, whereas a microcomputer is used as the graphic terminal. Interface programs are newly developed for this purpose. A technique is proposed here to minimize the transfer time of graphic data from the large computer to the microcomputer. Finally, the animation and the interactive tomography systems are developed as extensions of the graphic system.

Finite element analysis of thermal-hydraulics in upper plenum of pool-type LMFBR.

The pool-type LMFBR (liquid-metal cooled fast breeder reactor) is characterized by the unpredictably complex flow because of the complicated arrangement of structural components immersed in the liquid sodium. Such flow behavior must be fully understood for the sophisticated design of the LMFBR. Furthermore, the thermal-hydraulic feature of the pool-type LMFBR is one of the most important key issues from the viewpoint of reactor safety. The present study is devoted to the numerical analyses of the thermal-hydraulic characteristics of the pool-type LMFBR.The finite element method (FEM) is chosen for the spatial approximation, taking an advantage of the FEMs flexibility for the approximation of the complicated geometry. Considering the fact that the efficient computation is essential for the FE analysis of complicated three-dimensional flow, an efficient FE scheme for the incompressible viscous flow is proposed in the present paper. Focus of attention is placed on the time integration algorithm and some techniques for the reduction of storage demand. The proposed computational scheme is applied to the three-dimensional thermal-hydraulic problem in the upper plenum of the pool-type LMFBR to demonstrate the feasibility of the present FE strategy.