An Examination of Selected Problems in Rotorcraft Aeroelastic Stability

Aeroelastic stability results computed with the Rotorcraft Comprehensive Analysis System (RCAS) are correlated with experimental results from the Advanced Dynamics Model rotor test program (ADM). The ADM experiments were performed by the U. S. Army Aeroflightdynamics Directorate in the 1990’s to measure the damping of the first regressing lag mode of an isolated, torsionally soft, realistic blade tip Mach number, model rotor with both straight and swept-tip blades. The way in which inflow model affects correlation was assessed for uniform inflow and Peters-He dynamic inflow at four different levels of refinement Correlation of computed and test results are generally consistent with the correlation found by previous investigators—good in some areas and leaving room for improvement in others.