Applied Hydro- and Aeromechanics Author:Ludwig Prandtl, O. G. Tietjens Prandtl was one of the great theorists of aerodynamics. This work has long been considered one of the finest introductory works in the field. Topics include flow through pipes, Prandtl’s own work on boundary layers, drag, airfoil theory, and entry conditions for flow in a pipe.