论文标题
多维多尺度建模的交错网格
Staggered grids for multidimensional multiscale modelling
论文作者
论文摘要
由于截断误差和数值圆形误差,具有较小耗散的波浪状系统的数值方案通常不准确且不稳定。因此,缺乏适当处理这些数值问题的波动系统的数值模拟通常无法代表波现象的物理特征。对于多尺度建模,尤其是在多个维度上,这一挑战变得更加复杂。当使用通常的共处网格时,大约三分之二的分辨波模式在显着分散的情况下是不正确的。但是,交错网格上的数值方案(具有交替的可变布置)明显较小,并且保留了许多波形特性。同样,与共处的网格相反,交错网格上数值波中能量传播的基团速度是正确的。为了高准确性并保留了许多波动特性,本文将全域建模中交错的网格的概念扩展到了多维多尺度建模。具体而言,本文开发了120个多尺度交错的网格,并证明了它们的稳定性,准确性和波动性的特征,用于无方程的多尺度建模弱阻尼线性波。但是,开发的多尺度交错网格的大多数特征也必须在许多复杂时空的物理现象(例如一般计算流体动力学)的多尺度建模中通常具有。
Numerical schemes for wave-like systems with small dissipation are often inaccurate and unstable due to truncation errors and numerical roundoff errors. Hence, numerical simulations of wave-like systems lacking proper handling of these numerical issues often fail to represent the physical characteristics of wave phenomena. This challenge gets even more intricate for multiscale modelling, especially in multiple dimensions. When using the usual collocated grid, about two-thirds of the resolved wave modes are incorrect with significant dispersion. But, numerical schemes on staggered grids (with alternating variable arrangement) are significantly less dispersive and preserve much of the wave characteristics. Also, the group velocity of the energy propagation in the numerical waves on a staggered grid is in the correct direction, in contrast to the collocated grid. For high accuracy and to preserve much of the wave characteristics, this article extends the concept of staggered grids in full-domain modelling to multidimensional multiscale modelling. Specifically, this article develops 120 multiscale staggered grids and demonstrates their stability, accuracy, and wave-preserving characteristic for equation-free multiscale modelling of weakly damped linear waves. But most characteristics of the developed multiscale staggered grids must also hold in general for multiscale modelling of many complex spatio-temporal physical phenomena such as the general computational fluid dynamics.