Indicial-Function Approach Using an Euler Finite-Element CFD Code

New methods are proposed for achieving fast execution of aeroservoelastic aerospace vehicle flight-characteristics simulations. Specifically, the exploitation of approximate solutions that appear in the indicial-function representation of generalized aerodynamic forces is proposed. The essence of the innovation is transformation of the convolution integrals into a set of linear first-order differential equations that augment the system state vector; these added states are to be solved concurrently with the other system states that describe the rigid and elastic motions of the vehicle. The principal Phase I objectives are to demonstrate this indicial-function procedure with a finite-element Euler code and to document the reduced overall effort required for simulation studies in comparison with direct coupling of the Euler code with the solution of the vehicle motion equations.