Flow-induced random guided wave on an airfoil with application to passive structural health monitoring: A numerical...

Interactions between airflow and wing surface induce guided waves and vibrations propagating in the wing structure, which carry valuable information about the aircraft's structural condition. To develop a promising passive structural health monitoring (SHM) approach, it is important to understand the flow-induced guided waves, including the source distribution, frequency range, and propagation features. Therefore, this paper proposes an efficient numerical simulation scheme, which solves the fluid and solid domains separately and sequentially. The fluid domain simulation is carried out by the large eddy simulations (LES), which are solved for the velocity and pressure fields over the surface of the wing. The resulting wall pressure field on the wing surfaces, which varies randomly in both time and space, serves as the input source for the solid wave simulation in the wing structure, performed using the spectral element method (SEM). The wave signals sampled by an array of measurement points are used to explore the distribution of pressure fluctuation sources and their propagation modes through the wing structure. The simulation results demonstrate the potential feasibility of passive SHM to wing structures via flow-induced guided waves, as the dispersion curve can be accurately reconstructed if the sensor array placement is optimized.