SearcharxivSearch

arXiv subjects

Carlos Mendez

Publications and source records attributed to Carlos Mendez.

2 recordsLinked to original sources

Data-Driven Flutter Suppression via HODMD, DMDcand Constrained MPC

This work presents an interpretable data-to-control framework for actuator-constrained flutter suppression by combining higher-order dynamic mode decomposition (HODMD), dynamic mode decomposition with control (DMDc), and model predictive control (MPC). The primary case is a pitch-plunge typical section with a trailing-edge flap and rational unsteady aerodynamics. HODMD identifies the dominant frequency and growth rate in subcritical, near-critical, and post-critical regimes from four measured structural channels. With 2% RMS sensor noise, the near-critical growth-rate error is 1.8 x 10^-3 s^-1, substantially lower than with standard DMD without delay embedding. A five-state real reduced-order model is formed from the HODMD subspace, and its flap-input matrix is estimated from a small-amplitude PRBS record using DMDc. For an independent chirp input, the normalized error over all channels is 2.4 x 10^-3. The constrained MPC stabilizes the true post-critical plant for an initial pitch perturbation of 8 degrees with a flap limit of 1 degree, whereas saturated LQR designed from the same model reaches the prescribed validity limit. Three supporting studies assess transferability. SU2 simulations show HODMD frequency recovery consistent with the available spectral resolution; OpenFOAM dynamic-mesh calculations show nearly linear articulated-flap moment authority from 2 to 8 degrees with frequency-dependent gain; and a two-way SU2 Python-FSI case demonstrates bounded disturbance rejection using a proportional-derivative baseline. These studies support modal identification, actuator authority, and closed-loop feasibility, but are not presented as CFD-level MPC validation. The framework provides a reproducible route from early-time measurements to constrained aeroelastic control.

math.OC

Hydrodynamic characterization of bubble column using Dynamical High Order Decomposition approach

Bubble columns are present in several applications, such as chemical and biochemical reactors and petrochemical and environmental engineering industries. This variety of applications is why understanding the bubble columns' dynamics is essential. This paper aims to describe a 2D bubble column system by a data-driven method to comprehend its dynamics better. We provided a set of simulations considering different superficial velocities to produce training data. With this data set, we compared two approaches: the Fast Fourier transformation (FFT) and the High-Order Dynamic Mode Decomposition (HODMD). Our results showed that FFT could not adequately describe the system as it has been done for a long time in the industry. However, with a few measurement points, HODMD can well represent and reconstruct the dynamics of this complex dispersed multiphase flow system.

physics.flu-dyn