Operational identification of time-varying modal parameters for thermal structures of high-speed aerial vehicles

The high-speed aerial vehicles are unavoidably impacted by the aerodynamic heating effect due to their high speed, which may further result in the time-varying characteristics of their structures. The theoretical and finite element method (FEM)-based numerical approaches hardly acquire the real modal parameters of the in-flight (operational) aerial vehicles. Focusing on this problem, the parametric time-frequency-domain maximum likelihood method is introduced into the application of the high-speed aerial vehicles and the time-varying modal parameters are estimated by this parametric time-frequency-domain maximum likelihood method. Based on a high-fidelity simulation example, it is proved that the introduced method can identify the modal frequency and mode shapes even in the low signal noise ratio (SNR) cases and the method is suitable for the modal parameter estimation of thermal structures of high-speed aerial vehicles with notable time-varying natures, which can theoretically support the relative engineering studies and applications.