The research on micro air vehicles (MAVs) is progressing rapidly these days because of their potential applications in surveillance and reconnaissance. There are certain limitation on fixed wing MAVs, since the lift of any fixed wing aerial vehicles is directly proportional to wing span. To solve these kind of limitations, researchers proposed to introduce biomimetics to enhance the lift of these MAVs. This led to the new class of MAVs, the ornithopters. These ornithopters enhance their lift as well as thrust by exploiting the large scale vortical structures generated from flapping motion of their wings just like birds and insects. One of the main problems faced by these aerial vehicles is wind gust owing to their small size and weight.
All these factors confirm the vast scope of research to explore the role of gusty flows past flapping wings. The objective of present study is to understand the underlying flow physics past flapping wings subjected to different intensities and frequencies of wind gust using OpenFOAM based numerical computations. The flapping motion (pitching and/or plunging) is achieved using dynamic mesh motion solvers. A good amount of care has been taken to ensure the robustness of the mesh as OpenFOAM computations are quite sensitive about meshing. Using various post processing tools, the vortical structures are analyzed to understand the phenomena like flow separation, Leading Edge and Trailing Edge Vortices (LEV and TEV) and their interaction in the wake zone. The influence of vortical structures on force characteristics has also been investigated. The wake characteristics are studied using Fourier analysis to understand the interaction between pitching motion of the airfoil and inlet gust and to identify the pitching motion that would be capable of suppressing the effect of wind gust