NONLINEAR RESPONSE OF A NONROTATING ROTOR BLADE TO A PERIODIC GUST

A rotating slotted cylinder (RSC) gust generator installed in the Duke University low speed wind tunnel was used to generate a gust excitati on field, and the nonlinear response of a non-rotating flexible rotor blade to periodic gust excitations was studied theoretically and exper imentally. The quantitative agreement between theory and experiment in dicates that the assumption of an uniform chordwise gust angle of atta ck and an approximate solution procedure of the nonlinear equations ar e allowable for a high aspect ratio blade and the parameter range cons idered in this study. For a periodic gust flow field, the effects of g eometric structural nonlinearity and aerodynamic nonlinearity on dynam ic aeroelastic behavior are significant and lead to aperiodic or chaot ic motion when stall occurs. (C) 1996 Academic Press Limited