Direct Computation of Stability and Control Derivatives with Respect to Static, Dynamic, and Unsteady Variables

The generalized aerodynamic force method is developed. Closed-form matrix equations are derived for computing a complete set of stability and control derivatives directly from rigid-body generalized aerodynamic force matrices. These matrices are traditionally used for flutter analysis, so they are standard output from frequency-domain aerodynamic solvers, including some high-fidelity Navier–Stokes solvers. Verification against analytic solutions and validation against experimental data demonstrate the accuracy of the method. The method achieves accuracy comparable to analytic formulations, such as the steady-state adjoint method, while simultaneously providing derivatives with respect to unsteady variables.