Rapid vehicle aerodynamic modeling for use in early design

Reduced-order aerodynamic models developed to rapidly estimate the quasi-steady behavior of aerodynamic and bluff bodies were applied to the fuselage of a small quad-copter. A new model to generate the quasi-steady aerodynamic data on a complex body using data derived from canonical shapes is demonstrated and compared to high-fidelity Computational Fluid Dynamics (CFD) simulations. The resulting aerodynamic influences on controls and performance during maneuvers were assessed in a flight simulation framework. The dynamic behavior of the reduced-order model was found to be comparable to that obtained with CFD-generated quasi-steady data and better than flat plate models. This reduced-order approach provides a viable alternative to expensive CFD simulations or wind tunnel testing necessary to obtain quasi-steady aerodynamic predictions for complex vehicle fuselages. These unsteady aerodynamic models with relatively accurate quasi-steady aerodynamics are recommended over steady aerodynamic assumptions to more accurately estimate the performance, as well as dynamic behavior during aggressive maneuvers.