Accelerating Computational Fluid Dynamics Based Aeroelastic Predictions Using System Identification

System identie cation is evaluated as an efe cient and accurate technique for modeling unsteady aerodynamic forces for use in time-domain aeroelastic analysis. In the system identie cation methodology, the constant coefe cients of a linear system model are e t to the computed response time histories from a three-dimensional, unsteady computational e uid dynamics (CFD) solver. The resulting model of the unsteady CFD solution is independent of both dynamic pressure and structural parameters. Hence, this methodology has the advantage that only one CFD e owe eld computation for each Mach number must be completed to determine the aeroelastic instability boundary. Results show that system identie cation can accurately model the unsteady aerodynamic forces for complex aerospace structures of practical interest. The methodology results in a substantial savings in computational time when predicting aeroelastic instabilities.