Autonomic closure for turbulence simulations.
Autonomic closure for turbulence simulations.
复制标题
湍流模拟的自主闭合。
作者：
R. King;P. Hamlington;W. Dahm
提出了一种新的湍流闭合方法，消除了指定预定义湍流模型的需要，而是提供了完全自适应，自优化，自主闭合。闭包是自主的，在某种意义上，模拟本身通过求解非线性、非参数系统识别问题来确定任何未闭项和已解量之间的最佳局部、瞬时关系。这种非参数方法允许自主闭合自由地适应流动中的各种非线性、非局部、非平衡和其他湍流特性。在先验测试中，即使是简单地实现大涡流模拟的自主闭包，也比传统规定闭包的动态版本提供了更准确的结果。
A new approach to turbulence closure is presented that eliminates the need to specify a predefined turbulence model and instead provides for fully adaptive, self-optimizing, autonomic closures. The closure is autonomic in the sense that the simulation itself determines the optimal local, instantaneous relation between any unclosed term and resolved quantities through the solution of a nonlinear, nonparametric system identification problem. This nonparametric approach allows the autonomic closure to freely adapt to varying nonlinear, nonlocal, nonequilibrium, and other turbulence characteristics in the flow. Even a simple implementation of the autonomic closure for large eddy simulations provides remarkably more accurate results in a priori tests than do dynamic versions of traditional prescribed closures.