Quasi-3D Navier-Stokes Model for a Rotating Airfoil

A quasi-3D model of the unsteady Navier?Stokes equations in a rotating frame 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 turbulent flows past blades in pure rotation. In the turbulent case the influence of small-scale turbulence is modelled by the one-equation Baldwin?Barth turbulence model. The computations demonstrate that the main influence of rotation is to increase the maximum lift.