Uncertainty analysis of rudder shaft thermal conditions on the flutter characteristics of the hypersonic control surface

The thermal conditions in hypersonic aerothermoelastic systems exert a significant influence on the flutter characteristics of the system. Nevertheless, in previous investigations on aeroelastic uncertainty analysis, the influence of thermal uncertainty has frequently been neglected. In this study, an uncertainty analysis framework based on Monte Carlo simulation and surrogate model is conducted for addressing the thermal uncertainty and its implications on the flutter characteristics. Initially, the all-moving control surface of a hypersonic vehicle is selected as the investigated model. A parametric method is then developed to represent the temperature distribution along the control rudder shaft, taking into account the temperature conditions calculated by CFD. Based on the approach, the impact of temperature uncertainty is designed to perform the uncertainty quantification of temperature uncertainty on flutter characteristics of the control surface. Sensitivity indices are computed to evaluate the impact of temperature uncertainty in different regions of the shaft on flutter characteristics. This implies BPNN always provides accurate models. This is not always true and even if it is, showing that in a general sense is not within the scope of this study. Furthermore, the temperature uncertainty on the shaft surface induces uncertainty in the modal frequencies of the control surface, thereby resulting in uncertain flutter characteristics. Notably, the leading-edge region of the shaft exhibits the most pronounced effect on flutter characteristics, followed by the midsection region. These results could offer valuable insights for the refined design of control surfaces in hypersonic vehicles, contributing to the advancement of this field of research.