Despite advances in Computational Fluid Dynamics (CFD) methods; application of CFD to an aeroelastic analysis is still not well-accepted by the aerospace industry. Currently, the unsteady panel methods still are the major workhorse used by the aerospace industry because these panel methods can generate the Aerodynamic Influence Coefficient (AIC) matrix. The AIC matrix is a multi-input-multi-output aerodynamic transfer function. Because it is an aerodynamic transfer function, the AIC matrix is independent of the structure and only depends on the aerodynamic geometry. Thus, once the aerodynamic configuration is fixed, the AIC matrix can be repeatedly used for structural design. However, because of the linear potential flow assumption, the unsteady panel methods are not valid at transonic Mach numbers. In these flow conditions, accurate unsteady aerodynamic forces can only be obtained by solving the Euler or Navier-Stokes equations. Therefore, the aerospace industry would greatly benefit from having an innovative method that can efficiently generate the AIC matrix from the CFD methods.
The overall technical objective of this Phase I effort is to develop a CFD-based AIC generator to generate the structurally independent AIC matrices using high fidelity CFD codes. Using these AIC matrices, the generalized aerodynamic forces (GAF) can be rapidly computed for performing aeroelastic analysis. With a small computational effort, the AIC matrices also can generate the GAFs due to control surface kinematic mode and gust excitation.
Aircraft structural design requires flutter, aeroservoelastic (ASE), and gust analysis. Aeroelastic problems usually occur in the transonic flow regime at which the unsteady aerodynamics solved by the unsteady panel methods are not accurate. The proposed CFD-based AIC generator, once developed, will be well accepted by all aerospace companies.