Effects of upstream disturbances on a pitching NACA0012 airfoil

Dynamically moving airfoils are encountered in several areas of flight and energy production, including helicopter rotors, wind turbine blades, and maneuvering aircraft. A clearer understanding of how freestream disturbances affect the aerodynamic forces on pitching airfoils leads to improvements in aircraft and wind turbine design. In the present study, our recently validated moving overlapping mesh methodology is used to perform a direct numerical simulation of a NACA0012 airfoil pitching with oscillatory motion in the presence of a turbulent wake created by an upstream cylinder. The global computational domain is decomposed into a stationary background mesh, which contains the cylinder, and a mesh constructed around the airfoil that is constrained to pitch with predetermined reduced frequency, k=0.16. Present simulations are performed with chord based Reynolds number Re_c = 44; 000, with aerodynamic forces and vortex shedding properties being compared between the pitching airfoil simulations with and without upstream disturbances.