Wing model modal analysis in the airflow in conservative formulation

Abstract

Modal analysis of the elastic system dynamic properties is one of the most important types of research. The paper investigates eigen frequencies and oscillation modes of a wing model in the form of a flat rod of variable geometry, close to the real wing geometry in the air flow with zero angle of attack. Influence of the oncoming airflow is considered due to the internal force factors appearing under the frontal aerodynamic force action from the flow side. Aerodynamic forces and moments increment arising from the model small oscillations are not taken into account, i.e. the energy is not being “pumpe” at small oscillations from the airflow side, and the problem is solved in the conservative formulation. First three frequencies of natural oscillations and their corresponding forms are numerically determined; it is shown that all of them are purely bending. Dependence of the first three frequencies behavior on the oncoming flow speed was studied.