Matrix fraction approach for finite-state aerodynamic modeling

A least-square procedure for the finite-state approximation of the aerodynamic matrix is introduced, which is more efficient and/or simpler to use than those currently available. This is accomplished by starting from the approximation of the aerodynamic matrix as ND -1 or D -1 N, where N and D are matrices with polynomial dependence on complex reduced frequency p. Three different finite-state realizations based on the same matrix polynomial approximation are presented. The advantages of the approach and problems encountered in using the method are discussed. Numerical results are included