Originally Posted by rdeis
Hox does the Kf step compare with turbulation?
If the Kf step's main advantage is delaying stall, it would seem to do something similar to adding a trip strip to the airfoil, which also delays stall?
Good question but as there (to the best of my knowledge) has been no low Re scientific testing of a KF airfoil vs. a turbulated 'conventional' airfoil no one can really give a definitive answer.
From a theoretical point of view it's hard to see how the airflow can quickly re-attach to the wing surface if it goes over a deep KF step, and unattached flow creates drag. This might explain why the KFm airfoils with multiple small steps appear to have lower drag than single deep step designs? It's quite possible that these smaller steps might work in a similar way to turbulators.