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lordvon

57 karma · joined May 29, 2014

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lordvon··on Coanda Effect: Understanding Why Wings Work
It is helpful to realize the trigonometry of flight. Wings leverage a horizontal force (thrust) to get a larger vertical force (lift). Freestream momentum is deflected some net angle by a wing. If you take a horizontal vector and tilt it, the length is reduced, and the height is increased. The equal and opposite reactions of the freestream momentum deflection are lift and drag on the wing. Turns out, the change in height is larger than the change in length. The following equation expresses the lift to drag ratio: sin(phi) / (1-cos(phi)+f). The phi is not angle of attack, but the net tilt angle of the freestream induced by the wing. There is some correlation between the two of course. f is a non-conservative skin friction factor.

I view aerodynamic phenomena such as stall and Coanda effect as mechanisms that interfere or enable the deflection capability of wings.

lordvon··on Ask HN: Should I Be Fully Open About a Patentable Physical Technology Idea?
Thank you for your input. I am aware of the relatively new law change, and I should have mentioned it in the question (I edited it so that it is now). It is actually the reason I am asking. If we were still first-to-invent, I would go ahead and discuss away with any incubator I wanted, making sure to keep good records of my communications.

Filing presents two obstacles: time limit and cost. Filing a full patent requires lots of money, and filing a provisional patent gives you only a year to choose whether to file a full patent, or the idea is forever unpatentable.

It is really constricting to have to decide these things before being able to talk freely about it.

lordvon··on CUDA Pro Tip: Optimize for Pointer Aliasing
Thank you for submitting this article! I have always heard that FORTRAN is faster and commonly used in Aerospace, and I am glad to finally know why, as well as how to bridge the performance gap.
lordvon··on Ask HN: What Open Source FEA Software Do You Use?
Thanks! I will check it out. Why did you use OOF2?
lordvon··on Ask HN: What Open Source FEA Software Do You Use?
Yeah, the only problem with automation was boundary condition specification. I guess I could use shell scripts to infer the list of boundary points for every boundary condition, given I knew in what order the points in the mesh were created.
lordvon··on Ask HN: What Open Source FEA Software Do You Use?
Thanks! I will check it out.
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