Numerical simulations of dynamic-stall phenomena have been performed using
an implicit unfactored Navier-Stokes solver and various turbulence closures
, including linear and nonlinear low-Re eddy-viscosity models. The accuracy
of the models has been assessed against a range of experimental data for r
amping and oscillating aerofoils at subsonic and transonic conditions. The
computations indicate that the non-linear eddy-viscosity models better pred
ict the shedding of the dynamic-stall vortex and the unsteady aerodynamic l
oads.