Dynamic mode decomposition (DMD) has recently become a popular tool for the non-intrusive analysis of dynamical systems. Exploiting the proper orthogonal decomposition as dimensionality reduction technique, DMD is able to approximate a dynamical system as a sum of (spatial) basis evolving linearly in time, allowing for a better understanding of the physical phenomena or for a future forecasting. We propose in this contribution an extension of the DMD to parametrized dynamical systems, focusing on the future forecasting of the output of interest in a parametric context. Initially, all the snapshots -- for different parameters and different time instants -- are projected to the reduced space, employing the DMD (or one of its variants) to approximate the reduced snapshots for a future instants. Still exploiting the low dimension of the reduced space, the predicted reduced snapshots are then combined using a regression technique, enabling the possibility to approximate any untested parametric configuration in any future instant. We are going to present here the algorithmic core of the aforementioned method, presenting at the end three different test cases with incremental complexity: a simple dynamical system with a linear parameter dependency, a heat problem with nonlinear parameter dependency and a fluid dynamics problem with nonlinear parameter dependency.
翻译:动态模式分解( DMD) 最近已成为对动态系统进行非侵入性分析的流行工具。 将适当的正正心分解分解作为维度减少技术, DMD能够将动态系统作为(空间)基础总和,在时间上线性演进,以便更好地了解物理现象或未来预报。 我们在此建议DMD扩展至半流化动态系统,重点是在参数背景下对感兴趣的输出进行未来预测。 最初,所有相片 -- -- 不同参数和不同时钟 -- -- 都预测到缩小的空间,使用DMD(或其一个变异体)来近似未来瞬间减少的相片。 仍在利用缩小的空间的低维,预计减少的相片随后使用回归技术组合在一起,使得有可能在未来任何瞬间对未经测试的参数配置进行比较。 我们正在此展示上述方法的算法核心,在最后三个不同的测试案例中呈现递增复杂性: 简单的依赖性动态参数系统, 带有非线性依赖性直线性动态参数, 简单的依赖性参数系统。