Velocity Scaled Aeroelastic Testing of Advanced Turboprops

An innovative experimental procedure for the sub-velocity scale testing of anisotropic aeroelastic models is developed and applied to the Advanced Turboprop. The scaling laws for an anisotropic, rotating model are developed. These scaling laws indicate that by proper choice of model geometry, stiffness, and density, all of the important aeroelastic similarity parameters can be satisfied in a full-velocity scaled test. In a sub-velocity scaled test, all the similarity parameters except for the Mach number can be matched. The development of the model building technology to construct reduced stiffness anisotropic models for sub-velocity scaled testing is then reviewed. In order to experimentally verify the sub-velocity scaled procedure, a propeller model was constructed based on the G.E. UDF MPS model, and the aeroelastic and performance data are favorably compared. Finally, as an illustration of the versatility of the sub-velocity scaled approach, the model is used to demonstrate the sensitivity of ATP blade flutter to mass distribution.