Poudel, NareshYu, Meilin2019-02-112019-02-112018Naresh Poudel and Meilin Yu. "Numerical Study of Flapping-Wing Flow Physics in Nonuniform Freestream Using the High-Order Spectral Difference Method on Dynamic Unstructured Grids", 2018 Fluid Dynamics Conference, AIAA AVIATION Forum, (AIAA 2018-3087), https://doi.org/10.2514/6.2018-3087https://doi.org/10.2514/6.2018-3087http://hdl.handle.net/11603/127662018 Fluid Dynamics ConferenceIn this paper, a numerical study is conducted to understand the impact of nonuniform freestream on the aerodynamic performance of a flapping foil. Specifically, an unsteady flow environment is generated by stationary inline or staggered circular cylinder arrays upstream. A 2D NACA0012 airfoil is then placed at different locations downstream of the cylinder arrays, and oscillates in the nonuniform freestream. Unsteady flows over the flapping foil are numerically simulated by solving the 2D low-Mach-number-preconditioned compressible Naiver-Stokes equations on deformable unstructured grids using the high-order spectral difference method. The flow fields over a pitching airfoil in unsteady flow environments and the corresponding aerodynamic forces are analyzed and compared under different flow conditions. It is observed that the nonuniform freestream can significantly affect the unsteady vortex dynamics of a flapping foil, thus modifying the thrust and lift generation.13 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.© 2019 AIAAimpact of nonuniform freestreamaerodynamic performance of a flapping foilunsteady flow environmentnonuniform freestream2D low-Mach-number-preconditioned compressible Naiver-Stokes equations on deformable unstructured grids using the high-order spectral difference methodthrust and lift generationText