Did you ever wonder how the aerodynamic (fluid dynamic) principles were worked out in order to produce the high performance airplanes of the 50’s and 60’s were developed before the advent of computer flow models? Some of those aircraft sill hold records even today.
How did they test/teach and learn about complex problems of flow around struts, into jet inlets and over airfoils? Learn about that process here.
Flow Visualization part:1
Flow Visualization part:2
What has less drag, a smooth surface or one with imperfections such as rivit heads or seams?
Excellent video showing in real experiments you can understand and see. Shows what the boundary layer is, what a stall looks like (if you could see the air) and vorticity. EXCELLENT!
Notice also as the airfoil is inclining to higher and higher angles of attack, that the air is not split on what appears to be the most forward portion of the airflow, but rather below that portion of the airfoil. There is a ton of information here to help you understand why things work the way they do. Enjoy!
Excellent video from days of old that demonstrate some very important aerodynamic principles. The different drag produced by common objects is shown on a scale. You’ll be amazed.