Transonic aeroservoelastic analysis of civil aircraft based on overset field-panel method

Compared with subsonic, when a civil aircraft flies in transonic, it’s aeroservoelastic characteristics appear as obvious frequency deviation and stability margin decrease. he aeroservoelastic design in the transonic should be thoroughly taken into account during the preliminary design stage since the development cost is high, the test flight risk is high, and the design change cycle is lengthy for aircraft in the development phase. The unsteady aerodynamic calculated by DLM cannot take into account the effects of the transonic shock wave and the boundary layer. The unsteady small disturbance velocity potential is separated into steady and unsteady terms in order to calculate the transonic unsteady aerodynamic. Computational fluid dynamic （CFD）is used to solve the transonic steady term, and the unsteady terms are then calculated by solving the time-linear transonic small disturbance velocity potential equation using the unsteady flow field element method. The obtained transonic unsteady aerodynamic influence coefficient is substituted into the calculation of the frequency response function of the aircraft transfer function. The calculated results are compared with DLM aerodynamic model computation results and flight test results. The transonic aeroservoelastic analysis based on the Over Field-Panel Method is more consistent with the flight test results in terms of frequency deviation and stability margin reduction. Exploring the frequency and stability margin of the transfer function in the transonic region to provide a method for aerosevoelastic design in the transonic region.