PARAMETER-VARYING AEROELASTIC MODELING AND ANALYSIS FOR A VARIABLE-SWEEP WING

Establishing a parameterized aeroelastic model is one of the obstacles in aeroelastic research of the variable-sweep wing. The local modeling technology is widely known as a practical method for constructing a linear parameter varying (LPV) model. However, there has been a lack of effective methods to deal with the incoherency of the local aeroelastic models. The inconsistency of the local aeroelastic models is reflected in the discontinuity of the local structural and aerodynamic models with the change of the system parameters. To solve this problem, this paper proposed a bottom-up coherent processing method to deal with the incoherent local aeroelastic models of the variable-sweep wing. Firstly, the Hungarian algorithm was used to track the structural modes and sort them according to the modal branches. In this way, the matched modes can ensure the coherency of the structural models; Next, the incoherent problem of the aerodynamic model was solved by introducing a scaling matrix in the expression of rational functional approximation, such that the aerodynamic coefficient matrices were written in a coherent form. After the above two steps, the resulting local state-space models have a coherent form, and the aeroelastic state-space model at arbitrary swept angle can be constructed quickly by interpolating the coherent local state-space models, so the computations for the aeroelastic stability and the slow time-varying responses can be performed effectively. Simulation results demonstrated that the model obtained by interpolating on the incoherent aeroelastic models will lead to great modeling errors, while the one obtained by interpolating on the coherent local models can produce an accurate aeroelastic model at any given swept angle of the wing. This paper provides a useful, accurate and efficient modeling method of the parameter-varying aeroelastic system for the variable-sweep wing.