Abstract
This study evaluates the dynamic response of a centrifugal impeller to pulsating flow rates using Dynamic Mode Decomposition with Control (DMDc) to contribute improving turbomachinery's robustness. A surrogate model, which we developed in this study, was designed to capture both the one-dimensional transient behaviors and the three-dimensional unsteady flow field while reducing computational cost. Comparison with numerical and experimental results revealed that the one-dimensional DMDc model, derived using the Z-transform, successfully reproduces the frequency response of centrifugal impeller under various flow pulsation conditions. Especially, the surrogate model accurately predicted gain and phase delay. The three-dimensional DMDc model effectively captures dominant unsteady flow structures, including pressure rise pulsations and pressure pulsations induced by impeller-volute tongue interactions. These findings demonstrate the effectiveness of DMDc as a reduced-order modeling approach for analyzing unsteady flows in turbomachinery, offering a computationally efficient alternative to high-fidelity simulations.
