Reduced-Order Modeling of Resolved Turbulent Flows for High-Speed Fluid-Structure Interaction Analysis

This study presents a reduced-order model method capable of generating resolved turbulent boundary layer pressure fluctuation loads at a reduced computational cost for aeroelastic analysis. The model generates unsteady pressure loads over a deformed panel by decomposing turbulent boundary layer flow into temporal and spatial components. First, an unsteady pressure fluctuation history over a flat plate is reproduced by superimposing spectral proper orthogonal decomposition modes and frequencies, which are orthogonal in space and time. Subsequently, spatial corrections to the pressure fluctuation magnitudes of the reconstructed flow are implemented to account for regions of flow compression and expansion over the deformed panel. Two assumptions required to construct the reduced-order model are verified: (1) one-way coupling exists between turbulence and structural responses, in that the impact of the former on the latter is negligible, and (2) spatial turbulent pressure variation is a linear function of modal coordinates of structural deformation. The reduced-order model produces accurate spectral properties of pressure fluctuations, which is critical for accurate prediction of the excitation of structural modes; however, the model overpredicts the magnitude. The results enable high-fidelity unsteady aeroelastic simulations at a reduced computational cost.