Validation of UH-60A Rotor Blade Aerodynamic Characteristics using CFD

Comprehensive validation of the blade aerodynamic loads for the UH-60A rotor blade is conducted using a computational fluid dynamics based approach. The validation of the airfoil sections which constitute the blade are performed first followed by computational investigations on the effects of the swept tip. Finally, aerodynamic loads are obtained for a realistic forward flight scenario and correlated with flight test data. Investigations are also conducted on the physics of the flow to understand the notable features in the vibratory airloads. Good correlation with the experimental data is obtained for the SC1095 and SC1095R8 airfoil sections which constitute the UH-60A blade. The tip sweep is found to increase the hysteresis in aerodynamic loads for unsteady pitch oscillations. CFD computations are found to give good estimates for both the vibratory load phase and peak to peak pitching moments compared to the existing table lookup based linearized unsteady aerodynamic models.