Originally Posted by
Old Smokey
As this higher angle of attack occurs at a higher body angle, the frontal area of the total airframe ‘facing’ the relative airflow is greater, thus a greater value of S (Surface Area) in the
Drag = Cd ½ Rho V^2 S formula.
Smokey, I’m having a wee bit of a problem with an item from your last post.
From what I’ve read here at PPRUNE, the use of the area term is just a reference number, and has in the past been used, among other things, as the value of wetted area, wing area, frontal area, or just plain the number “1.000”. As long as it was a constant, it was the choice of the person presenting the data.
And thus I’m not sure when using the equation for profile drag D = .5 rho Cd Vsq S that it is fair to say that the profile drag depends on weight because of a changing frontal area. Consider if S was wetted area, for example, then weight certainly would not have any effect on S. Certainly though, increased weight has an effect on total drag, but I thought it was only in the term induced drag…..
Perhaps MFS or the newly returned E have an input…..