Hi again,

My question one is I have attached the images I got from Javafoil below. The airfoil I made is the one that is on the airplane kit I am building. Please guys can you tell me whereabouts does the boundary layer separate? Please just mark the spot on one of the attached images. I am guessing that the separation occurs where the blue pressure colour suddenly turns suddenly green on the flow field picture for the Cp, pressure coefficient. Also, when the more negative the Cp is, the less the pressure is there right? And the mroe positive it is, the stronger the pressure is? Am I right?

My second question is this. How do you figure out the needed wing area for lifting a certain weight? I have ane quation which states that S=W/(W/S)

where:

W= gross weight
S= wing area

Okay, I can agree with this formula as it boldly compares the weight of the airplane and it's wing loading. Reasonable enough- but not quite what is wanted here. That equation assumes that the wing is some flat planform/surface which must provide 30 g of lift per squre meter should it's wing ladoing be 30g/m^2. But, what if I am using an airfoil which DOESN't provide that much lift?

I guess that what I am trying to say is basically I want an equation better than the one above of the common one L=Cl times 1/2 times p times V^2 times S

Any person who is at least half a foot into the field of aerodynamics knows this formula. But it is a very simple formula which provides you with lift given by a wing with no freaking airfoil?! What I want is an equation where a set of input variables are the characteristics of the airfoil I chose to put onto my wing, so that the wing dimensions I get are the ones for a wing with MY airfoil on it. Get me? I guess that Cl is one factor that I must know from my chosen airfoil but is that enough? What about the Cp or Cdp, parasite drag coefficient. I guess that to get the perfect wing dimensions you need to winf tunnel test it, but as I dont have the luxury of one how else can I find the close to exact size for my wing???

Thanks guys. I appreciate the answers.