Turbulent flows past airfoils
Our
turbulent flow computations over a NACA 0012 airfoil not only predict
the phenomenon of {\it stall} but also pick-up the associated hysteresis close
to the stall angle. The ability of the flow to remember its past history is
responsible for its hysteretic behavior. For the same angle of attack, the flow
obtained with the increasing angle results in an almost attached flow
with higher lift and lower drag while the one with decreasing} angle
of attack is associated with large unsteadiness, lower lift and higher drag
Figure 9 The method is now being applied to multi-element airfoils
that are deployed during take-off and landing. This research is funded by AR
& DB.
Re=10^6, turbulent flow past a NACA 0012 at airfoil at
=18° Hysteresis