Cubdriver, what are some good sources for boundary layer reading that we could understand?
Originally Posted by nciflyer
*For a wing, think of the wing as a restriction and the free-stream air above it as another restriction. A certain mass flow rate of air must flow through this restriction that is the wing and free-stream air above. Sometimes I like to think of a wing as half a venturi where the air above replaces the missing half.
Originally Posted by
Cubdriver
No, this will not do. I get tired of people thinking I am busting their balls so please refer to NASA:
Good to know I'm wrong here... I'm liking that NASA page...
Originally Posted by
Cubdriver
Whoa, we are in wild places here academically. Boundary layers involve viscosity and Thin Airfoil Theory, which is the basis of modern aerodynamic theory, does not deal with viscosity at all. It is a basic premise of Thin Airfoil Theory that it applies only to inviscid fluids. To deal with the whole thing we have the Navier Stokes equations and the Euler equations. You are speculating about tradeoffs that supercomputers struggle with. You are familiar with any of this? Thin Airfoil theory is given in low-speed aerodynamics for engineers. You got to pay some dues to play that game and I am remiss if I do not mention it. Prandtl would toss a rock from from his grave if I did not ding you here. You know who I am talking about right?
No, I'm not familiar with who you're talking about... I took an introductory class years ago that was designed for pilots not engineers, so we discussed the concepts without getting deep into the math and theory. We only spent a day on boundary layer and mostly talked about where energy is gained and lost and velocity gradients and pressure gradients. [Edit add] So to say the least, I definitely don't understand the subject fully nor have I before.
Originally Posted by nciflyer
*When the air first meets the wing leading edge it must accelerate. When it reaches it's maximum velocity the boundary layer is thinned and hence the smallest restriction to go through. This can sometimes be about 1/3 to 1/2 of the chord back from the leading edge.
*After this max velocity point above the wing the boundary layer will get thicker in general and the air must slow down because there is less of a restriction for the air.
*So this decrease in velocity means kinetic energy is reduced and potential is increased. We don't want this because we want to keep as much kinetic energy as close to the wing as possible....
What statements could replace my false ones above?