Recent content by RainmanAero

Hi Fred, You are right, but only as Mach numbers approach transonic. For low speeds (< Mach 0.6) it is sufficient to match the Reynolds Numbers. As one moves above this rule-of-thumb threshold it becomes more and more important to match Re and Mach. At least that is what I've been...

verdigris, (You took my quote out of context, so I had to correct it above so folks would not get the wrong idea of what I was saying).You are now obfuscating the issue by mixing apples and oranges. An airfoil (by definition) is a 2-dimensional object and the flow analysis is likewise only...

verdigris, Methinks your verbal analysis is quickly turning your idea into a Rube Goldberg special! Once you put holes in your bag you are now faced with another aspect of nature and that is pressure equalization. While you may think you can control the rate at which the gas is "squeezed...

Warren, I've highlighted the absolute in your statement to show you where it can lead to trouble. If what you are saying is true, then a cambered airfoil flying at zero angle of attack should produce no lift. But clearly we know that this is not true. :bugeye: Again the penchant for...

Warren, In my opinion you should be careful about statements of absolutes in your pronouncements. There is one aspect of lift production by a wing that you cannot escape as truth, and it is derived from Bernoulli's principle: The lifting force of a wing scales directly with dynamic...

Russ is correct. And it should be noted that people can talk themselves into such traps because they do not follow the first "law" of engineering: Draw A Free-Body Diagram & Label the Forces! Talk is cheap. Engineering is expensive (but effective!) :smile: Rainman

Hi Clausius, Actually, I now travel down to Rancho Bernardo every TUE for a UAV project that I am working on. Tomorrow might be too short on notice, so perhaps next week? Will PM you later. Rainman

You are, of course, correct Clausius! Thanks for keeping me honest! I was assuming an attached shock only, but you are certainly correct that there is the additional case of the detached bow shock. My bad. Since I work on supersonic aircraft, where we always tend to purposefully keep the...

Hello Jack, I am going to try and help Clausius help you out. You need to help us out by understanding the things we are describing to you, verifying to us you understand, and then giving us more information about your question with regards to what we have described to you. I would first...

Hi Fred, Correct me if I am wrong here, but I think there might be two more caveats (actually, boundary conditions) that might need to be added to quote the second law in its complete form: Entropy increases for a system that is: a) Isolated and b) Far from thermal equilibrium. I...

giber, What, precisely, do you mean by aerodynamic stabilization of satellites? I would presume you know that there is no air in space, and as such any form of aerodynamic control surfaces (such as used on aircraft) are ineffective. And I think you should also define what specific form of...

Hi Folks, I've been enjoying the time off work for the holidays, and trying not to think about engineering and stuff... but once it becomes a way of life it is hard to stay away from it. I just found the following on the "Massive Yet Tiny (MYT)-TM" engine. I am only now starting to look...

Hi Dave, I was told an electromagnetic actuator was "not even close" (see above). I guess as long as we are shooting in the dark (or at least dusk), then I should also mention the magnetic brake which operates on Lenz's Law. It does not even require power, but depending upon the details...

As a prof of systems engineering, I feel I should address some fallacies and typical causes of problems down the road: Knowledge is a tricky thing. Passing on knowledge is even trickier if your media for doing so is limited. The fact that we are asking questions (to try to visualize) means...

Look guy, If you're going to get snooty when I am trying to help you, then why don't you take my other advice and do a drawing? And to be snooty right back, I'd suggest you learn how to write specs. You'll need that talent: No, to be honest, it doesn't. You say the block clamps down...