A wide range of devices employ airfoils operating at relatively low chord Reynolds numbers and unsteady flow conditions, such as UAV’s and wind turbines. The process of designing airfoils for those devices relies upon numerical simulations using both panel codes (XFOIL) and Navier-Stokes solvers (CFD), which predictions are in fair agreement with the experimental data for thin airfoils far below aerodynamic stall. Moreover, those methods lack in prediction of unsteady flows or pitching movement, which is regarded as a representative example of an unsteady flow. When an airfoil passes through unsteady flow in pitching motion, pressure fluctuations are generated on its surface in a way that is not fully verified. To widen the knowledge on aerodynamic characteristics on airfoil in pitching motion and unsteady flow, NACA 0018 airfoil was manufactured and tested in closed loop wind tunnel. A novel rig design allowed a harmonical pitching motion, while passive grids generate turbulent flow inside the wind tunnel. A dense chordwise distribution of pressure taps allowed time-resolved surface pressure measurements that are used to experimentally investigate aerodynamic forces and characteristics of the separation of the flow over the airfoil in comparison to static conditions. The experimental setup allows a variation of mean pitching angles and amplitudes, Reynolds numbers and turbulence intensities.
The role of continuous gust and prescribed motion on blade aerodynamics and broadband noise
Light refreshments will be served after the lecture at the lounge
