Kutta-Zhukovsky Circulation Theory is presented as a "mathematical theory" based on the "trick" of the Kutta condition, to be compared with "physical theories" commonly connected to Newton and Bernoulli. This is presented as follows:
- There are several ways to explain how an airfoil generates lift. Some are more complicated or more mathematically rigorous than others; some have been shown to be incorrect...Wikipedia) (
- The mathematical description of lift is a general term for the analysis tools of classical aerodynamics and computation aerodynamics. If the objective is to accurately compute the principle or aerodynamics of a wing, these are the tools to use, though the aerodynamic description is mathematical and not physical. (Understanding Flight)
- There are different explanations of flight: 1. Mathematical, taught to aeronautical engineers. 2. Popular, taught at flight schools, NASA, in many cases fine but wrong. 3. Physical, presented by myself in this lecture. (Jefferson Lab Science Series/Eberhardt)
- How can potential flow be adapted to provide a reasonable theoretical model for the flow around an aerofoil that generates lift? The answer lies in drawing an analogy between the flow around an aerofoil and that around a spinning cylinder. For the latter it can be shown that when a point vortex is superimposed, a lifting flow is generated. (Aerodynamics for Engineering Students, 5th edition, by Houghton and Carpenter)
- The airflow about an airfoil may be viewed as consisting of two superimposed patterns—one is the free-stream motion of the air about the airfoil and the other is a circulatory flow, or circulation, around the airfoil. (US Centennial Flight Commission)
See also Unphysical Circulation Theory.