Experiment investigation and principium analysis for vibration on aerodynamics of a model airfoil

Vibration will affect the precision and reliability of wind tunnel experiments results. In this paper, applying the driving equipments which are specially designed to do plunging and pitching vibration, NACA0012 airfoil is chosen to test with larger incidences. By measuring dynamic and static pressure distribution on airfoil surface respectively, the aerodynamics performance can be investigated and analyzed. And based on the solution of unsteady Reynolds-Averaged Navier-Stokes equations, the flow field around airfoil at high incidences are also investigated under consideration of vibrations for wind-tunnel models. Both of the experiments and fluid calculating results are shown that the vibrations of the airfoil can cause large scale unsteady separated vortex shedding before the stall incidence, therefore, lead to lift decreasing and the stall appearing at some lower incidence than the steady meaning stall incidence. Concerning these two vibration modes, the effects of airfoil's pitching is more serious than that of plunging. These conclusions illustrate that the stiffness of the aircraft model wing should be stronger in the process of model's design, particularly with large aspect ratio model wings. The significance of the paper work will contribute to improve the precision and reliability of wind tunnel experimental results.