tgrayson
New Member
I think you're making a false distinction here, like saying you haven't fallen until you hit the ground and the slip on the patch of ice is unrelated
. Any buffet produced by a stall strip is an incipient stall, the turbulence being caused by airflow separation and reattachment. And where the buffet occurs is likely where the full stall will occur. If the strips were located at the root, they would also likley produce a buffet, because the turbulent airflow impinges on the horizontal stabilizer, just like what happens with the Hershey bar wing.So the real question isn't whether the strips cause a buffet or a stall, since it's the same thing, but why the designers chose the location they did. Your notion that the location was chosen purely due to enhanced buffets seems to be based on the unwarranted certainty that your wing already stalls at the root. You don't know that. The tapered outer portion tends to stall at the wing tip, and, as we discussed, washout can't always compensate for that. Moreover, these problems are often discovered late in the product development cycle when large changes to the aircraft design are very expensive. Stall strips are one of a variety of inexpensive "aerodynamic fixes" that can be applied during production flight testing. Since stalling at mid-wing is better than a wing-tip stall, its location is perfectly compatible with correcting stall behavior, just as it's compatible with an enhanced buffet. These two issues are probably intertwined, since any wing that stalls at the root most likely doesn't need any buffeting enhancement, due to the reason given above.
But this still leaves the main question unanswered: given that root stalls produce good buffeting and good stall behavior, and a mid-wing location can produce good buffeting and stall behavior, why did the designers choose one over the other? We don't have enough information to know. The section I quoted from the flight testing book should have conveyed that the location of these strips is a highly empirical one; they place them where they work. There might be some airflow characteristics of this airplane that made the root an unsuitable location, perhaps, for instance, due to the propeller slipstream. I've read of too many strange flight test problems to think that I can predict why any particular airplane is designed the way it is. At best, I can discuss broad design goals and how certain features typically affect them, but every airplane has its own issues.
