An investigation for realization of general and rapid scheme of numbrical simulation of fluid flow

点击翻译按钮获取中文摘要

Rhia incwarifrion qa xeeiws our ro impeocw rhw xompuroe xosw ro mwwr rhw scnxw of the computor hardware. Some kinds of computor codes of flow simulation were made fast amd addaptive to wider flow conditions. Following flow fields were treated as the representative of flow. 1) viscous flow around a bydy, 2) Fully 3-D flow within impellers of turbomachineries, 3) Turbulent shear flow and 4) Acoustic field in a flow passage of complicated configulation.For problem 1), speed-up of the calculation was persued for the SOR and SLOR method which are employed in the finite difference calculation of the flow around a circular cylinder and a sphere submerged in a uniform flow. For the problem 2), a fast and highly accurate code for the direct problem of both incompressive and compressive flow in centrifugal and axial impellers of turbomachineries was realized on the basis of panel method. The calculation of influence factor was highly vectorized. A new method of employing spectral method for the … More treatment of non-linear terms for the case of compressive flow was also useful to speed-up the calculation. Also an inverseproblem for the same flow was freated on the basis of of actuator-duct method, which allowed us to design a impeller based on fully 3-D calculation within a reasonable computor time,i.e., less than 10 minutes for 1 run using SX-2. The problem 3) was the central part of this series of investigation. Newly developped code allowed to emoploy 4.2 million grids without using external memory and achieved more than 99% of the vectorization factor which made the calculation world record in size and at the same time 1/10 in computor time compared wity the ones available in litteratures. By this code, the basis of numerical simulation of turbulent sheaf flow was well established. A Patched grid technique was also tried in order to make the code adaptive to variety of flow fields. The problem 4) dealt with Helmholtz' equation and was treated by a panel method. The same technique as the problem 1) was applied to this problem.Also the fundamental solution of viscous acoustic wave equation was newly found. Less