Large-Eddy Simulation of Turbulent Separated Flows Using Advanced Computational Procedures

近二十年来，大涡模拟（LES）已成为湍流研究的有力工具。速度和内存不断提高的计算机现在也使得使用直接数值模拟（DNS）计算一些湍流成为可能。提出了利用并行计算技术研究分离湍流流场的LES问题。这项研究将确定这些流动的湍流统计数据。所提出的计算在内存和CPU时间方面非常密集，因此，在多处理器计算机上实现应该导致开发有效的算法。该研究将为分离湍流的LES数值算法的发展提供宝贵的经验和知识，然后可以有效地应用于使用类似流动的DNS进行更密集的计算。为了近似空间导数，将使用四阶有限差分和光谱离散相结合的方法。时间导数将用隐式方法逼近。建议的方法将在CRAY- YMP8/864上实施。

Large - Eddy Simulation (LES) has served as a powerful tool for turbulence research over the last two decades. Computers with ever increasing speed and memory have also now made it possible to compute some turbulent flows using Direct Numerical Simulation (DNS). The research on LES of separated turbulent flows is proposed using parallel computing techniques. The study will determine the turbulence statistics for these flows. The proposed computation is very intensive in terms of memory and CPU time and, therefore, implementation on a multi-processor computer should lead to development of an efficient algorithm. The study will provide valuable experience and knowledge in the development of numerical algorithms for LES of separated turbulent flows, which can then be effectively applied to even more intensive computations using DNS of similar flows. To approximate the spatial derivatives, a combination of fourth- order finite-differences and spectral discretization will be used. Time derivatives will be approximated by an implicit method. The proposed methods will be implemented on CRAY- YMP8/864.