Publication

Abstract : An aeroelastic model of a 2D airfoil, having a nonlinear spring stiffness, is analyzed when subjected to unsteady aerodynamic loads. Theodorsen's unsteady aerodynamics is considered, and the aeroelastic equations derived are solved using multistep differential transform method (MSDTM). MSDTM provides an alternative to overcome the drawbacks of the differential transform method (DTM) for finding solutions in a broader interval. The solution of the governing aeroelastic equations solved using MSDTM predicts the flutter boundary and identifies the existence of limit cycle oscillation (LCO). The occurrence of LCO near the neighborhood of the flutter condition is investigated. The obtained numerical results show the method's effectiveness in solving such nonlinear systems with remarkable accuracy compared to the other numerical methods like the Runge–Kutta (RK) method. The effect of initial conditions, nonlinear pitch stiffness and the different geometric parameters of the airfoil on the aeroelastic behavior beyond flutter speed are investigated. Solutions derived using MSDTM predict a benign nature of flutter for the aeroelastic system considered.