Numerical simulation of dynamic stall of NACA0012 airfoil oscillating near static stall angle using the navier-stokes equations.

摘要

Unsteady stall called as dynamic stall. has been experienced in unsteady motions of rapidly maneuvered airfoils. In order to establish the method for predicting the behavior of unsteady aerodynamic forces during dynamic stall process. numerical simulations on the dynamic stall phenomena of the NACA0012 airfoil oscillating near the static stall angle were performed using the compressible Navier-Stokes equations. The flow Pattern, instantaneous pressure distribution, and behavior of the lift and pitching moment during dynamic stall were examined in detail. Computations showed that the major features of the dynamic stall phenomenon were qualitatively well reproduced. namely the formation of the leading-edge separation vortex and the behavior of the lift and pitching moment hysteresis loops. However. comparisons of the resultant pitching moment hysteresis loops with experimental data indicated that further research is necessary to obtain a rigorous quantitative prediction of unsteady aerodynamic forces arising from the massively separated flows. 13 refs., 19 figs.