Theoretical and Experimental Study on Nonlinear Response of a Rotor Blade to a Gust

A rotating slotted cylinder (RSC) gust generator installed in the Duke University low speed wind tunnel was used to generate a gust excitation field and the nonlinear response of a flexible rotor blade to gust excitations was studied theoretically and experimentally. The quantitative agreement between theory and experiment indicates that the assumption of an uniform chordwise gust angle of attack and an approximate solution procedure of the nonlinear equations proposed are allowable for the parameter range considered in this study. For a periodic gust flow field, the effects of geometric structural nonlinearity and aerodynamic nonlinearity on dynamic aeroelastic behavior are significant and lead to aperiodic or chaotic motion when stall occurs.