UNSTEADY AERODYNAMIC FORCES AND AEROELASTIC RESPONSE FOR EXTERNAL STORE OF AN AIRCRAFT

An experimental identification investigation of unsteady and stall aer odynamic coefficients for an external store of an aircraft has been ma de. The coefficient identification is performed by a least-squares pro cedure based on the measured time series obtained from an aeroelastic model undergoing aerodynamic excitation caused by a gust generator. Th e results are verified by the good correlation between the theoretical prediction and aerodynamic measurement data. Using the identified uns teady aerodynamic model, numerical investigations for both the stabili ty (flutter) and nonlinear aeroelastic response of this external store model have been made. Also, the results were compared with those obta ined from a quasisteady aerodynamic model. It is seen that the effects of unsteady aerodynamics on the nonlinear aeroelastic response are si gnificant when the angle of attack is large.