Numerical simulation of vortex unsteadiness on a slender body at high incidence

Numerical results obtained with the present3D thin-layer Navier-Stokes solver are shown to qualitatively follow experimental results. They also indicate the existence of at least two main frequencies on an ogive cylinder at 40 and 60 deg angles-of-attack: (1) a low frequency associated with fluctuations of the primary vortices, and leads to vortex shedding, and (2) a high frequency associated with shear-layer fluctuations that are concentrated in several small areas above the leeward side of the body's cylindrical portion.