Numerical analysis of the effects of wing's oscillation on its aerodynamic characteristics in wind tunnel tests

The average aerodynamic characteristics of an oscillating wing in low speed flow have been investigated by solving the unsteady N-S equations and compared with that of the rigid wing. The structural modes and corresponding frequencies have been obtained by making use of the Finite Element Method (FEM). Assuming that the wing takes the first-order mode as its form of movement, the computations have been conducted at various angles of attack and amplitudes and the results have been studied carefully. The following conclusion has been reached: the average aerodynamic characteristics of the wing undergoing slight oscillations don't show any significant difference from that of the rigid wing, but with the growing amplitudes of the oscillations increasing differences between these two sets of results show up, showing growing decreases in the maximum lift coefficients and stall attacks. The results presented in this paper have partly explained the fact that the maximum lift coefficient and stall attack in wind tunnel tests are usually smaller than the CFD results where the wing is considered rigid.