Efficient Creation of Aeroservoelastic Models Using Interpolated Aerodynamics Models (2011)


Daniel Hammerand, James Gariffo, Kevin Roughen


The expense of running computational fluid dynamics (CFD) and computational structural dynamics (CSD) codes motivates the creation of aeroservoelastic models which can be interpolated accurately to unmodeled flight conditions. Furthermore, both the analyzed and interpolated points can be used to design modern control laws for flutter suppression, gust load alleviation, and ride quality enhancement. One interpolation method involves taking the weighted average of the assembled aeroservoelastic models themselves. One shortcoming of such a methodology is the inability to create additional aeroservoelastic models that correspond to changing the dynamic pressure, since the aerodynamics and structural dynamics have been combined together. For linear representations, the aerodynamics are taken to change linearly with the dynamic pressure. Hence, it should be a straightforward task to create additional linear aeroservoelastic models that correspond to changing the dynamic pressure only. The present study examines just such a possibility in detail. A consistent basis is used for interpolating the aerodynamic models is used to produce accurate models that can be safely combined with the structural and actuator models in generating the final aeroservoelastic models. The results presented for the AGARD 445.6 wing demonstrate the efficiency of interpolating the aerodynamic model separately before integrating into the aeroservoelastic model. The effectiveness of creating a control law for flutter suppresion for such interpolated points is shown for a subsonic case.