The Response of a Single Degree-of-Freedom Wing at Low Reynolds Number

Abstract

A torsional spring was added to the leading edge of a rectangular aspect ratio four flat plate wing to observe the effect of discrete compliance on the wing force response. Spring stiffness was varied between a completely free-to-pivot and a rigidly attached wing, with two cases in between. The addition of springs was found to hold the wing at a higher angle of attack than the free-to-pivot case and thus increase force production. The wing acceleration distance and Reynolds number were also varied. Reynolds number had a significant effect on the steady-state forces due to variation in the dynamic pressure, but acceleration had little impact. A low order model of the wing dynamics based on thin airfoil theory is discussed and applied to the specified wing kinematics. The results of this model show promising agreement during the transient and reasonable success once the wing has reached steady state.