  The paper presents a numerical investigation of the leading-edge vortices
generated by rotating triangular wings at Reynolds number $Re=250$. A series of
three-dimensional numerical simulations have been carried out using a Fourier
pseudo-spectral method with volume penalization. The transition from stable
attachment of the leading-edge vortex to periodic vortex shedding is explored,
as a function of the wing aspect ratio and the angle of attack. It is found
that, in a stable configuration, the spanwise flow in the recirculation bubble
past the wing is due to the centrifugal force, incompressibility and viscous
stresses. For the flow outside of the bubble, an inviscid model of spanwise
flow is presented.
