One warning to the novice is that his experiments all take place at a very low Reynolds number. It's very difficult for neophytes to visualize flow at these scales, not least because the shape of the viscous boundary layer is on nearly the same size scale as the wing itself. In fact, it was long believed that "ideal" wings for aircraft would have a very thin cross section, primarily because this is what worked so well in the tiny wind tunnels of the day. Just look at the difference between an early WWI fighter and a late WWII bomber. (IIRC, we actually lucked into this for structural reasons! Thicker wings are easier to build!)
Over and above that, because the Coanda effect pertains to detached streams, it doesn't actually apply to a baseball, nor to wings. The author seems bright enough to handle potential flow calculations, and it would be a very instructive exercise for him to model a 2D flowfield around an airfoil without circulation, and then to input enough circulation to account for the Kutta condition at the trailing edge. I would advise using a "typical" cross section to avoid certain irregularities around the leading edge. Fundamentals of Aerodynamics, by Anderson, is a wonderful read, even if it is surprisingly infuriating to learn how hopelessly wrong typical aerodynamic intuitions are.
My fluids prof used to comment that people feel perfectly confident making pronouncements about aerodynamics where they'd be appalled to make the equivalently technical statements about brain surgery.
If you push an symmetric elongated body at a non-zero angle of attack in potential flow it will generate lift without (applying the Kutta condition to generate) circulation.
Perhaps your first paragraph explains why the Spitfire had thin wings. IIRC, one unintended consequence of this choice was that, as power and speed increased through WWII, the Spitfire avoided compressibility problems.
Comments
One warning to the novice is that his experiments all take place at a very low Reynolds number. It's very difficult for neophytes to visualize flow at these scales, not least because the shape of the viscous boundary layer is on nearly the same size scale as the wing itself. In fact, it was long believed that "ideal" wings for aircraft would have a very thin cross section, primarily because this is what worked so well in the tiny wind tunnels of the day. Just look at the difference between an early WWI fighter and a late WWII bomber. (IIRC, we actually lucked into this for structural reasons! Thicker wings are easier to build!)
Over and above that, because the Coanda effect pertains to detached streams, it doesn't actually apply to a baseball, nor to wings. The author seems bright enough to handle potential flow calculations, and it would be a very instructive exercise for him to model a 2D flowfield around an airfoil without circulation, and then to input enough circulation to account for the Kutta condition at the trailing edge. I would advise using a "typical" cross section to avoid certain irregularities around the leading edge. Fundamentals of Aerodynamics, by Anderson, is a wonderful read, even if it is surprisingly infuriating to learn how hopelessly wrong typical aerodynamic intuitions are.
My fluids prof used to comment that people feel perfectly confident making pronouncements about aerodynamics where they'd be appalled to make the equivalently technical statements about brain surgery.
If you push an symmetric elongated body at a non-zero angle of attack in potential flow it will generate lift without (applying the Kutta condition to generate) circulation.
Perhaps your first paragraph explains why the Spitfire had thin wings. IIRC, one unintended consequence of this choice was that, as power and speed increased through WWII, the Spitfire avoided compressibility problems.