Two-Dimensional Localized Flow Control Using Distributed, Biomimetic Feather Structures: A Comparative Study

This paper presents the development of a bioinspired flight control system and a characterization of its performance when operating in turbulent and gusting airflow conditions. This design consists of a skeletal structure with a network of feather-like panels installed on the upper and lower surfaces, extending beyond the trailing edge. Each feather is able to deform into and out of the boundary layer, thus permitting local airflow manipulation. The gust load sensing is predominately performed near the leading edge of the airfoil, and the reaction forces are generated by the feathers located at the trailing edge. For this study, the focus presents a benchmark case of the NACA 4412 airfoil with the standard 20% trailing edge flap design operating in a gusting, turbulent airflow. COMSOL Multiphysics is used to model the flow field and the fluid-structure interactions using Direct Numerical Simulation. The dynamics of the gusting model are developed using MATLAB and LiveLink connected to COMSOL to enable unsteady, turbulent simulations to be performed. Discrete and continuous gusts are simulated at various airfoil angles of attack. Additionally, the airfoils’ aerodynamic performance is comparatively analyzed between time-varying and steady-state turbulence models. This paper discusses how these two-dimensional, time-varying turbulent and gusting airflow simulation results can be developed and integrated into a LQR closed-loop feed back flight control system.