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

她说，她希望我们能提高电脑硬件的竞争力。一些流动模拟的计算机程序，使其速度快，适应范围广。以下列流场作为流动的代表。1)粘性绕流，叶轮内全三维流动，湍流剪切流动，复杂湍流通道内声场等问题，对1）问题，本文采用SOR和SLOR方法对均匀流中圆柱和球体绕流进行了有限差分计算，并对计算结果进行了分析。对于问题2），基于面元法，实现了对离心叶轮和轴流式叶轮内无压和有压流动正问题的快速、高精度计算。影响因子的计算高度矢量化。提出了一种新的谱方法， ...更多信息 对压缩流的非线性项的处理也有助于加速计算。本文还利用作动器-管道法对同一流动进行了反问题求解，使我们能在合理的计算机时间内设计出全三维计算的叶轮，即：使用SX-2进行1次运行的时间少于10分钟。问题3是这一系列调查的中心部分。新开发的程序可以在不使用外部存储器的情况下使用420万个网格，并实现了99%以上的矢量化因子，这使得计算规模和计算时间都达到了世界纪录，与文献中的计算方法相比，计算时间减少了1/10。该程序为湍流层流的数值模拟奠定了基础。为了使程序能适应各种流场，还尝试了一种拼接网格技术。问题4）涉及Helmholtz方程，用面元法处理。将与问题1）相同的技巧应用于该问题，并新发现了粘性声波方程的基本解。

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