Tom....
As I recall, one way I got the scientific papers was through a Google search. For example: Spolek+American Journal of Physics+flycasting........You get a choice of web sites and pick as you see fit. Some papers are free, and some can only be obtained by paying a fee.
Don Phillips', THE TECHNOLOGY OF FLY RODS contains some interesting bits of physics relating to fly rods, fly lines, and casting. Worth studying whether or not one is interested in physics and mechanics. (Don has a degree in mechanical engineering from the U. of Mass.)
Gordy