Data-driven feature identification and sparse representation of turbulent flows

Autor: Andrew Wynn, Mohammad Beit-Sadi, Jakub Krol
Rok vydání: 2021
Předmět:
Zdroj: International Journal of Heat and Fluid Flow. 88:108766
ISSN: 0142-727X
DOI: 10.1016/j.ijheatfluidflow.2020.108766
Popis: Identifying coherent structures in fluid flows is of great importance for reduced order modelling and flow control. However, extracting such structures from experimental or numerical data obtained from a turbulent flow can be challenging. A number of modal decomposition algorithms have been proposed in recent years which decompose time-resolved snapshots of data into spatial modes, each associated with a single frequency and growth-rate. Most prominently among them is dynamic mode decomposition (DMD). However, DMD-like algorithms create an arbitrary number of modes. It is common practice to then choose a smaller subset of these modes, for the purpose of model reduction and analysis, based on some measure of significance. In this work, we present a method of post-processing DMD modes for extracting a small number of dynamically relevant modes. We achieve this through an iterative approach based on the graph-theoretic notion of maximal cliques to identify clusters of modes and representing each cluster with a single representative mode.
Databáze: OpenAIRE