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Showing posts from June, 2024

More patents, less papers

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Recently, my second journal article in the series ( The Unsteady Full Multi-wake Vortex Lattice Method: a full rolled-up detached vorticity approach [1]) was declined for publication four months after its acceptance (already peer-reviewed) in a second quartile (Q2) journal. This is not due to lack of consistency in methodology or results, but due to lack of the payment of the Article Processing Charge (APC)!, which neither the university nor the Science Council 'can' afford, although both of them are included in the remaining two articles, published without APC in a Q1 journal. Fortunately, I have never been interested in becoming an  paper-publishing researcher  to try to play the game imposed by the current academic system; I have only published my research as a requirement to obtain my PhD degree. However, this does not mean that I believe that knowledge should be restricted; ideally, the knowledge should be open and universal, especially when it concerns the foundations of

What is lift "force"? NASA is wrong!

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There is a classic figure shown in "theory of flight" (for pilots) and "aerodynamics" and "flight mechanics" subjects (for aeronautical engineering students) that shows a free body diagram with four "forces" acting on an airplane: weight (W), thrust (T), lift (L), and drag (D). Even the NASA Glenn Research Center website shows it: Fig. 1 Retrieved from:  What is Lift? | Glenn Research Center | NASA NASA begins by answering the question, "What is lift?" :  "Lift is the force that directly opposes the weight of an airplane and holds the airplane in the air...Lift is a  mechanical aerodynamic force  produced by the motion of the airplane through the air" . But are lift and drag really forces? Or are they just the perpendicular and parallel projections of a resulting force vector? I am pretty sure that all aerodynamicists at NASA know the correct answer. It is true that presenting it in this way is easier to explain to kids and

A fundamental question in fluid dynamics: vorticity generation

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Is vorticity generation at surfaces a viscous mechanism? This is one of the fundamental questions in fluid mechanics, and it has a big impact on how fluid dynamics (FD) and aerodynamics are understood today. I posted such a question a few days ago in a Linkedin group called "Computational Fluid Dynamics" with about 28K members. Surprisingly, it has been replied to by 34 people so far (about 0.12%), which is actually more than expected, considering that most of the publications there do not get a single "click" (most of them for "likes"). Do not be cruel, click on them! Fig. 1 Results for the question after 34 votes (were 35, but someone removes his participation). I suspect that this "huge result" is due to the controversial nature of the question, which has been simplified to reach a wider audience. According to public information, the participants come from universities to research centers, including both industrial and academic profiles. Howe