EAGER: Reaching Higher in Numerical Simulations of Turbulence

1139037 yeung湍流流体流动发生在许多科学和工程领域，其特征是在大范围内波动的复杂性，以至于它们的详细计算是值得使用世界一流的计算资源的首要挑战。该项目的核心目标是在计算和科学上进行密集的努力，以确保在一个真正持续千兆级能力的新机器上以新的世界纪录的分辨率成功地进行湍流中的混合和分散的大规模研究。目标模拟将达到8192立方（超过五万亿）网格点的分辨率和超过大多数实验室实验的雷诺数。为了取得成功，在追求几个新兴的新计算范式的复杂性时，需要克服智力上的挑战，包括混合多核编程和计算与处理器间通信之间的重叠，这与所采用的数值方法的逻辑以及新机器硬件的特征有关。在比以往任何时候都高的雷诺数下进行模拟和随后的数据分析，将使湍流波动的间歇性以及这些波动对湍流混合和分散的许多方面的影响的研究取得重要进展。在未来的NSF Track 1 Petascale机器上进行完整仿真代码的代码开发和新编程模型探索的策略具有固有的风险，因为此时系统的特性尚未完全已知或确定。然而，支持代码开发的紧迫性是巨大的，因为机器计划在2012年可用，CPU时间将会受到NSF预先批准的许多研究团队的极大需求。模拟的结果和由此产生的前所未有的庞大数据库预计将引起全世界湍流界的兴趣，并对许多社会关注的问题感兴趣，包括燃烧装置的效率和环境中污染物的扩散。为了使这项工作的科学影响最大化，使大型数据集更好地维护和更容易访问的挑战将通过主要超级计算机中心提供的服务来解决。这项工作还将为高水平的研究生提供独特的培训机会，这与之前两位研究人员联合指导活动的成功相呼应。

1139037YeungTurbulent fluid flows occurring in many fields of science and engineering are characterized by the complexities of fluctuations over a wide range of scales, to the extent that their detailed computation is a premier challenge worthy of the use of world-class computational resources. The core objectives of this project are to pursue intensive efforts both computationally and scientifically to ensure successful conduct of a massive investigation of mixing and dispersion in turbulent flow, at a new world-record level of resolution on a new machine of true sustained Petascale capability. The targeted simulation will reach a resolution of 8192-cube (more than half a trillion) grid points and a Reynolds number which exceeds most laboratory experiments. In order to succeed, there are intellectual challenges to be overcome in pursuing the intricacies of several emerging new computational paradigms, including hybrid multi-cored programming and overlap between computation and interprocessor communication subject to the logic of the numerical methods employed as well as characteristics of the new machine hardware.The conduct of the simulations and subsequent data analyses at Reynolds number higher than ever achieved before will enable important progress in the study of intermittency of turbulent fluctuations and the effect of these fluctuations on many aspects of turbulent mixing and dispersion. Strategies for code development and exploration of new programming models for the full simulation code on the future NSF Track 1 Petascale machine carry inherent risk, because of the massive size of the system whose characteristics are not fully known or determined at this time. However the urgency for supporting code development is great since the machine is scheduled to become available in 2012 and CPU hours will be in great demand from a number of research teams pre-approved by NSF. Results from the simulations and consequent unprecedented massive database are expected to draw interest from the turbulence community worldwide and be of interest in many problems of societal concern, including the efficiency of combustion devices and the dispersion of pollutants in the environment.To maximize the scientific impact of this work the challenges of making large datasets better maintained and more readily accessible will be be addressed via services provided by major supercomputer centers. This work will also provide a unique training opportunity for a graduate student of high caliber, echoing the success of prior joint mentoring activities by both investigators.