This is wrong. The Coanda effect is about fluid jets; this is how blown flaps work. However an airfoil is in a free-moving fluid not a jet.

[edit] A complete mathematical modeling of lift from first-principles is essentially impossible, as the most straightforward method would likely be Navier-Stokes. That, however, has serious issues with turbulent flow, which will happen somewhere IIRC it becomes quite inaccurate in stall conditions.

It's been a long while since I've done any physics, but my recollection is the practical way to model it is to use Navier-Stokes along with empirically determined approximations of turbulence.

[edit2] A quick reading of the wikipedia article tells me that was mostly right, but NS doesn't have the stall issues, it's the Euler equations (which is a simplified form of NS).