Listen to Birkhofff expressing his criticism of Prandtl and modern fluid mechanics. The mathematician Garrett Birkhoff addresses in the opening chapter of his book Hydrodynamics from 1950 several paradoxes of fluid mechanics including d’Alembert’s paradox, and expresses a clear doubt in their official resolution attributed to Prandtl: I think that to attribute them all to the neglect of viscosity is […]
The New Theory of Flight is now confronting the ruling paradigm of aerodynamics formed by the Fathers of Modern Aerodynamics Kutta, Zhukovsky and Prandtl, which has dominated all through the 20th century into present time. The New Theory is based on computational solution of the Navier-Stokes equations and thus represents information society, while the Old […]
Modern aerodynamics formed by its fathers Kutta, Zhukovsky and Prandtl, resulted from a crisis of classical mechanics with the prediction of zero drag and lift in slightly viscous flow falsified by observation as expressed in d’Alembert’s paradox. To resolve the paradox two ad hoc assumptions were introduced: An airfoil with sharp trailing edge will generate […]
Popper states in Knowledge Without Authority (1960): The empirist’s questions “How do I know? What is the source of your assertion?” are wrongly put. They are questions which beg for an authoritarian answer. I propose to replace, therefore, the question of the sources of our knowledge by the entirely different question: “How can we hope […]
Continuing from the preceding post we are led to classify science as follows: Science: Basic assumptions directly falsifiable. Quasi-Science: Basic assumptions not directly falsifiable, but certain consequences of the basic assumptions falsifiable. Pseudo-Science: Basic assumptions not directly falsifiable, nor any consequence of the basic assumptions. Examples: Solid Mechanics based on Navier’s equations expressing equilibrium of […]
According to Popper, a theory is scientific if and only if it is falsifiable in the sense that there is some prediction of the theory, which can be tested or compared with reality and thus be falsified if it comes out negative. According to Popper a scientific theory can never be verified, only be made […]
Two unique short videos with the Fathers of Modern Aerodynamics Prandtl and Zhukovsky speaking, have recently been put up on Youtube: Prandtl Discovers the Boundary Layer Zhukovsky Discovers Circulation Generated by Sharp Trailing Edge. See also Nikolay Yegorovich Zhukovsky.
The slides for my talk at Variational Multiscale and Stabilized Finite Elements VMS 2012 at Christian-Albrechts-Universität zu Kiel is now available for inspection.
Let us see how Wikipedia handles the fact that there is no convincing explanation of how a wing generates large lift at small drag, which makes it possible to fly for both birds and airplanes. We quote from Lift Force: There are several ways to explain how an airfoil generates lift. Some are more complicated […]
A common feature of pseudo-science is theory claiming a substantial effect from a small or unknown cause making experimental testing impossible. Let us subject modern fluid dynamics to this test. Modern fluid and aerodynamics is dominated by Ludwig Prandtl named Father of modern fluid mechanics and Zhukovsky named Father of Russian aerodynamics supported by his […]