Wing Loadings: The Idiots Guide?

[drgondog]

I meant the airflow from the slat goes over the LE of the wing and over the upper surface and does not flow allong the bottom surface of the wing. (at High AoA, as seen in the diagrams)

up to point of stall ALL airflow moves over top and bottom surface of the wing. It MUST do so in order to obtain lift. Theoretically speaking, two 'tubes' of freestream air which hits leading edge stagnation point, split and must reach trailing edge stagnation point at same time.

Use a Clark Y for easy illustration - The tube over the top surface must travel faster over the top surface to reach the trailing edge at the same time... therefore ----> higher velocity (lower pressure than freestream) and also higher velocity than the bottom tube velocity.



Not to start this whole argument up again, but the article virtualpilots.fi: 109myths which has the second diagram seems refer to "liftloading" (note, no space) in the context Soren was using it. I then did another google search of "liftloading" and found several other refrences to the term (all as one word) that seem to match Soren's usage. (the majority of which seem to be referring to the BF 109)

KK - the author of "Why Kit Carson Was an Idiot" article appears to have the same academic background in Aerodynamics as Soren - at least he seems contemptuous of any academics that Kit Carson brought to the table with the following comments

They found out that the proposed "washout" did not help but made the stall characteristics worse! Yes, Mr. Carson, it made it worse!! Germans and Willy DID know about washout! So take you poor schoolar knowledge you learned from some books and :/$/"§$!"§$ !!!

Hard to make a case that his 'theory' about liftloading is based on any theoretically sound basis. BTW you notice that his result is in #/Ft^2 which is 'implied' as a lift loading.

In fact, Lift/Clmax = 1/2*rho*V^2 ---> which SPECIFICALLY is 'q" , the freestream dynamic pressure and has ZERO relevance to 'lift loading' in this context and everything to do with freestream Velocity

This particular article could also be where Soren came up with the idea of 'Lift loading' as an expression of WL/Clmax


Why Carson was an idiot
This one in particular uses it in Soren's exact context. (additionally the Clmax figures seem much lower than what I've seen for the listed a/c)

see above

QUOTE]

KK- Cl has only one source in Aerodynamics. It is

Cl = Lift/(1/2*rho*V^2 x Wing Area)

Using Cl in any equation brings the dynamic pressure expression into the calculation. Period.

 

[kool kitty89]

What did seem interesting in that article, was (as I mentioned) the use of fences on the Hispano Ha 1112 in place of the slats. (an in testing on prototype Bf 109's)

I didn't know that a wing fence coulld improve lift characterstics on an unswept wing.



When I was talking about the airflow over the slats earlier, I was referring to conditions at high AoA (pact the unslotted wing's critical AoA). Would my statements still be wrong in that case?

 

[drgondog]

What did seem interesting in that article, was (as I mentioned) the use of fences on the Hispano Ha 1112 in place of the slats. (an in testing on prototype Bf 109's)

I didn't know that a wing fence coulld improve lift characterstics on an unswept wing.

KK- wing fences and vortex generators are put on wings to improve chord wise flow - conversely to reduce spanwise flow. More commonly required for swept wing but you see vortex generators near nacelles on modern turbo prop jobs

When I was talking about the airflow over the slats earlier, I was referring to conditions at high AoA (pact the unslotted wing's critical AoA). Would my statements still be wrong in that case?

Not so much 'wrong' as incomplete. The flow will always be somewhat attached on the bottom surface of a wing even at critical AoA. (consider laminar flow over a flat plate)

At critical AoA the boundary layer on top surface has grown to point of introducing turbulent flow and the BL continues to separate - and the pressure on the top surface is becoming 'less and less' negative relative to freestream -thereby losing lift