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

Ria incwariFrion Qa xeiw是我们的计算机硬件的一部分。编制了几种流动模拟的计算机程序，使之快速适用于更广泛的流动条件。随后的流场被视为流动的代表。1)涡流绕流的粘性流动，2)叶轮内部的全三维流动，3)湍流剪切流动，4)复杂结构流道中的声场。对于问题1)，本文对均匀流中绕圆柱和球的流动的有限差分计算中采用的SOR和SLOR方法进行了加速。对于问题2)，在面元方法的基础上，实现了叶轮机械离心轴向叶轮非压缩流和压缩流正问题的快速、高精度计算程序。影响因素的计算高度矢量化。一种利用谱方法计算…的新方法对于压缩流动的情况，更多地处理非线性项也有助于加快计算速度。同时，在激励器-风道方法的基础上，解决了同一流动的反问题，使我们可以在合理的计算机时间内，即用SX-2进行一次计算，在全三维计算的基础上，设计出一个叶轮。这个问题是这一系列调查的核心部分。新开发的程序可以在不使用外部存储器的情况下情绪化420万个网格，并实现了99%以上的矢量化因子，使计算在规模上创造了世界纪录，同时与文献中提供的计算相比，计算机时间缩短了1/10。该程序为湍流床层流动的数值模拟奠定了基础。为了使程序适应不同的流场，还尝试了一种补丁网格技术。该问题用Helmholtz方程处理，并用面元法进行处理。采用与问题1相同的方法求解该问题，得到了粘性声波方程的基本解。较少

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