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We present a numerical approach for the computation of gust flows around bodies. We are mainly interested in computing the aerodynamic coefficients under gust effects. The highest computational accuracy is thus required in a close vicinity of the body. The method we propose is an hybrid approach coupling high-fidelity computations (solving the Navier-Stokes model) around the body with lower fidelity computations based on Proper Orthogonal Decomposition (POD). In other words, the POD basis functions can be viewed as giving accurate boundary conditions to the small computation domain surrounding the body. This is obtained projecting the solution of the detailed model on the POD basis functions over a predefined overlapping region. The gust is taken into account in the POD expansion using additional basis functions as usually done for the control function method. These functions are computed as being the gust transport along the whole domain without any body. This method is highlighted on a simple however complex two dimensional flow around a circular cylinder, and around a 3D elastic airfoil for low to moderate Reynolds numbers.

Gust, POD, CFD