Numerical and Experimental Study on the Ability of Dynamic Roughness to Alter the Development of a Leading Edge Vortex

摘要

Both computational fluid dynamics, using two- and three-dimensional commercial flow solvers (FLUENT), and experimental analysis (Particle Image Velocimetry) is used to document the ability of sub-boundary layer oscillating surface perturbations (dynamic roughness) to alter the development of a leading edge vortex (LEV) on an airfoil undergoing dynamic stall. It is known the vortex developed on the leading edge helps sustain lift significantly beyond the static stall angle of attack, but once this vortex is shed downstream there is an abrupt loss in lift and change in pitching moment. The ability to delay or instigate LEV development can lead to methods able to take advantage of the sustained lift while limiting the consequences associated with the shedding of the vortex. Both computational and experimental results show the ability for dynamic roughness to alter the development of a LEV on a rapidly pitching airfoil.