A Comprehensive Rotorcraft Aeroelastic Analysis with Trailing Edge Flap Model: Validation with Experimental Data

A comprehensive aeroelastic analysis developed to investigate plain trailing edge flaps for vibration control is validated by comparison of vibratory loads with experimental wind tunnel data and that of another comprehensive analysis. Correlation between predicted and measured frequencies was generally fair. Results for hover thrust and power required agreed well with the experimental data. Some discrepancy was observed near the low thrust condition, possibly resulting from the inflow modeling used for hover. In forward flight, fair correlation was observed for the power required and longitudinal cyclic pitch. However, the lateral cyclic pitch was underpredicted. For the baseline rotor with no trailing edge flap motion, overall correlation of blade bending was good, although significant discrepancies in the steady values of the loads were observed. With trailing edge flap moving ±4° at 5/rev, the analysis overpredicted the 5/rev flatwise bending moments due to the flap motion, while the the blade torsional moment was predicted fairly well.