A quasi-3D model of the unsteady Navier-Stokes equations in a rotating fram
e of reference has been developed. The equations governing the flow past a
rotating blade are approximated using an order of magnitude analysis on the
spanwise derivatives. The model takes into account rotational effects and
spanwise outflow at computing expenses in the order of what is typical for
similar 2D calculations. Results are presented for both laminar and turbule
nt flows past blades in pure rotation. In the turbulent case the influence
of small-scale turbulence is modelled by the one-equation Baldwin-Barth tur
bulence model, The computations demonstrate that the main influence of rota
tion is to increase the maximum lift. (C) 1999 Academic Press.