drgondog
Major
Ok fair enough Bill, I apologize for the sarcasm then. And let's be objective about this.
About the slats first;
My thesis is not and has never been that the slats deploy fully in conditions close to straight flight, and I honestly can't really understand how you interpret it that way either. Also I don't bring forth any thesis on this subject only the facts.
You need to understand that the slat deployment process is gradual, the slats starting to deploy at a very low AoA's, not fully extending ofcourse, but extending out slightly. And so in climbs, landing approaches and slow turns a pilot wont even notice the slats popping out unless he looks at them as the deployment process is so slow and the slats themselves not fully extended. However if the pilot banks hard where the Critical AoA of the original airfoil is reached nearly instantly, then he will feel a very slight notch on the stick as the slats pop out to their fully deployed position almost instantly.
Furtermore the slats aren't linked together, they're completely independant of each other, and thus so is the deployment process. So if one wing is starting to stall before the other then the slat on that wing is also further extended.
As Mark Hanna puts it:
"As the stall is reached, the leading-edge slats deploy-together, if the ball is in the middle and slightly asymmetrically, if you have any slip on."
Anyway got get back to work now, will address the rest later.
PS: Glad we can discuss this in a calm objective manner Bill.
Soren - this is the statement which triggered my comments
Oh when it comes to the issue of pressure distribution and boundary layer seperation I see things quite clearly Bill, and nothing of what I explained is wrong, nothing.
The slats start to deploy at very low AoA's as the pressure on the top of the wing becomes lower than the pressure under the wing, making the slats extend. Quite simple.
Typically leading edge slats deploy at near stall conditions. Low angle of attack typically is not near stall for any aircraft until low speeds. Typically at medium to high speeds in normal flight regimes the stagnation pressure on the zero lift/flow diversion point..
from a theoretical point the flow is brought to a specific point on the nose of the airfoil and changes its momentum at that point - then travels over the top and bottom surface of the airfoil.
So, the slat at that point of the wing for free stream impingement, is experiencing 'positive pressure (relative to freestream) then as the flow travels normally back and over the top surface, the pressure distribution in comparison to the free stream (and the stagnation point on the slat) becomes rapidly 'negative' over the surface of the airfoil for the maximum lift region, then drops rapidly to freestream pressure as separation begins and finally to freestream pressure in the region of the boundary layer wake.
So, from my perspective the only way a slat should deploy is when the pressure behind the slat is at same or slightly higher dynamic pressure behind the slat as the dynamic pressure on the nose of the slat - which is a typical stall condition.... otherwise the slat is conceptially 'pressed' against the wing surface behind it.
If the slat deployment occurs in level flight at low AoA versus either level flight at high AoA at low speed or medium AoA in a normal turn, then I would not happily fly that a/c because it implies that indicial gusts in normal flight or even in a relatively slow turn could cause the slat to deploy.
The F-86 slat deploys at high AoA. I had read from Mustang Designer that it was a close design approach to the Me 262 slat... so I am confused by your statement that the Me 109 slat deploys at low AoA for all the reasons I just relayed above.
If you were to draw a free body diafram mappring out the forces on the leading edge slat at low AoA, how would you describe it..