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Old 22nd Apr 2016, 16:28
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KenV
 
Join Date: Aug 2014
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these two (2) concepts are fairly straight-forward.
1) The F-22 is 62-foot long. The F-35A is 50.5-foot long. The F-22 is 11.5 foot longer. The F-22 has a 44.5-foot wide wing span. The F-35C has a 43-foot wide wing span. So which aircraft most closely conforms to the Sears-Haack body? The answer mostly explains why the F-35C struggles to accelerate in the transonic region.
Wow!!!! You’ve changed your story! First you were arguing about Whitcomb area rule. When that argument fell apart you changed it to Sears-Haack body. FYI, those are two very different subjects, both of which you totally misunderstand. The Sears-Haack body derivation is based on the Prandtl-Glauert equation which is not remotely valid in transonic flow, and area rule applies essentially only in transonic flow. Indeed the Prandtl-Glauert equation contains a singularity! Where? At mach 1 where the flow resistance asymptotically approaches infinity. That was the source of the “sound barrier” term in the late 40’s and why people thought that mach 1 was impenetrable. The Sears Haack body was first derived in 1941, long before the Bell X-1 and long before Whitcomb’s area rule. Or to put it more simply so hopefully even you understand, the two concepts are only superficially related, with area rule applying only in the transonic region of flight, and Sears-Haack appling only in the supersonic region of flight. You mixing and equating these two concepts pretty much confirms what we all suspect: you know how to do google searches and can cut and paste, but you have no idea what it is you are cutting and pasting.


Further, the Sears-Haack body applies ONLY on the limit of a slender, axisymmetric body, like a missile or artillery projectile and is why the V2 had the shape it had. Neither the F-22 nor the F-35 are slender nor axisymmetric. For non-axisymmetric (but still slender) bodies one must use the Robert Jones extension. But again, neither the F-22 nor F-35 are slender, where slender means a fineness ratio of at least 4.5. F-22 has a fineness ratio of about 1.4 and the F-35A about 1.5. To put this in perspective the F-104 fineness ratio=2.5, Concorde=2.4, SR-71=1.9 and V-2=8.5. So none of these aircraft are even candidates for a Prandtl-Glauert, a Sears-Haack or even a Robert Jones body analysis. Only the V-2’s shape and dimensions are applicable. So not only are you barking up the wrong tree, you’re in the wrong forest.

Sears-Haack shaping makes a radical improvement in the performance of soap box derby cars rolling down a hill at 15-miles per hour. Right? We all know that. All things being equal, a Sears-Haack shaped soap box derby car will win every time...
Oh. My. Goodness. A Sears-Haack body is axisymmetric, has a fineness ratio greater than 4.5 and is pointed at both ends. Let's see you use your google skills to find a soap box derby car with that shape. Kids have been doing soap box races since 1914 when Charlie Chaplin popularized it in a movie. They've been using streamlining principles basically from day one. Streamlining (of cars, locomotives, ships, and even soap box and pinewood racers) predates by several decades the Prandtl-Glauert equation and the Sears-Haack body. In case you missed the implication, lets be clear: such streamlining has NOTHING to do with Sears-Haack or area rule. But nice try at obfuscation.

Come to think of it, the same goes for MSOCS. Instead of the ad hominem assaults, perhaps you have a better answer to this question?
Oh my. Now you've displayed your gross misunderstanding on an entirely different subject. You’ve discovered the fancy term ad hominem, but completely misunderstand its meaning. The folks on this forum have described the contents of your posts here as turds. They have not called you a turd. The latter is ad hominem, the former is not. You on the other hand have called folks "fanboys" as well as hurling multiple personal insults. Look up the term “hypocrisy”. Sadly, it does not apply in your case. Hypocrisy is willful. Your posts indicate you are too ignorant for your actions to be willful. But they certainly are embarrassing, assuming of course embarrassment is even possible for you. That remains doubtful.

Last edited by KenV; 22nd Apr 2016 at 17:26.
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