Sparse sensing and DMD based identification of flow regimes and bifurcations in complex flows

TL;DR

This paper introduces a robust, data-driven sparse sensing method based on Dynamic Mode Decomposition (DMD) for real-time identification of flow regimes and bifurcations in complex thermo-fluid systems, demonstrated on a 2D heated cavity simulation.

Contribution

The paper develops a novel augmented DMD-based classification approach that is noise-robust and effective with limited sensor data for flow regime identification.

Findings

Successfully classifies flow regimes from short sensor data sequences.

Robust to measurement noise and effective with few sensors.

Captures main flow dynamics through DMD modes and eigenvalues.

Abstract

We present a sparse sensing framework based on Dynamic Mode Decomposition (DMD) to identify flow regimes and bifurcations in large-scale thermo-fluid systems. Motivated by real-time sensing and control of thermal-fluid flows in buildings and equipment, we apply this method to a Direct Numerical Simulation (DNS) data set of a 2D laterally heated cavity. The resulting flow solutions can be divided into several regimes, ranging from steady to chaotic flow. The DMD modes and eigenvalues capture the main temporal and spatial scales in the dynamics belonging to different regimes. Our proposed classification method is data-driven, robust w.r.t measurement noise, and exploits the dynamics extracted from the DMD method. Namely, we construct an augmented DMD basis, with "built-in" dynamics, given by the DMD eigenvalues. This allows us to employ a short time-series of data from sensors, to more robustly classify flow regimes, particularly in the presence of measurement noise. We also exploit the incoherence exhibited among the data generated by different regimes, which persists even if the number of measurements is small compared to the dimension of the DNS data. The data-driven regime identification algorithm can enable robust low-order modeling of flows for state estimation and control.