Messy1
Master Sergeant
I agree. Love the soundtrack! Queen One Vision, Twisted Sister, good stuff. Far fetched movie, but I thought it was cool in it's day.
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Because Soren says so, I don't know....
Quit it now Joe! What do you know? You only have actual real world flight experience in high speed twin engined fighter jets, that does not come close to "real world book knowledge"!
Fine, since you're of the opinion I have nothing to contribute with I'
ll shut up.
Bill said:I would start with L/D but that would be silly me.
Bill said:If you wish to maintain the AR of the F-14 in transonic to supersonic is greater - prove it (it will be tough).
You frequently have a lot to contribute
Oh, I guess the below doesn't qualify as L/D related:
" However the higher AR of the F-14's wing gives it more lift and less drag pr. area, which is also what allows it to land on a carrier while the F-15 would be completely incapable of that because of it's higher stall speed."
Hmmm - the span of the F-14 is 38 ft swept. To you that means in transonic to supersonic config. The area is 565 ft^^2 in both configs.
AR for the sweptback wing is 38*38/565= 2.55
AR of the 'extended wing' at low speeds is 64*64/565 = 7.2
The span of the F-15 is 42 ft. The area is 608ft^^2
AR = 42*42/608 = 2.9 ~ 13% better than the F-14 from transonic up to max speed (which is higher than F-14)
The span of the F-16 is 32 ft. The area is 300ft^^2
AR = 3.4 ~ 33% better than the F-14 from transonic up to max (which is slightly lower than F-14)
Lift Loading at 1g. All higher g lift loading at equivalent g's are proportional, except that F-14 not designed for 9 G's
Nominal loaded weight for F-14 (not max Take Off) is 61K
61000/565 = 118 #/ft sq
Nominal loaded weight for F-15 is 44,500
44500/608 = 73 which is ~ 67% of the F-14
Nominal loaded weight for the F-16 is 26,500
26500/300 = 88 which is ~ 21% of the F-14
Is your thesis that the way you wish to discuss ACM capability is in the pattern up to 350 kts?
Hmmm... I guess this didn't make sense to you:
I think I pointed out that the extended wing was subsonic and maybe transonic to supersonic transition. Above that the extension would be questionable - but I'm willing for you to prove that the F-14 deployed at all speeds and explain the automatic mechanism for deployment and retraction - then explain how the F-14 navigated between supersonic and subsonic ac shifts from a stability poit of view?
"The wing sweep action works automatically on the F-14, adjusting according to the flight mode of the a/c. If entering a tight turn the sweep is varied automatically to give the best results. This gives it better turn performance."
So, your thesis is that the F-14 will not lose energy like a drunken sailor by 'popping it's wings at say 800 kts?
But then again, what do I know, I'm not an aerodynamics expert who bases all his comments on "facts" like you are...
That is correct Soren.
As for span loading, again:
"Aspect ratio and planform are powerful indicators of the general performance of a wing, although the aspect ratio as such is only a secondary indicator. The wingspan is the crucial component of the performance. This is because an airplane derives its lift from a roughly cylindrical tube of air that is affected by the craft as it moves, and the diameter of that cylindrical tube is equal to the wingspan. Thus a large wingspan is working on a large cylinder of air, and a small wingspan is working on a small cylinder of air. The smaller cylinder of air must be pushed downward by a greater amount in order to produce an equal upward force; the aft-leaning component of this change in velocity is proportional to the induced drag. Therefore a large downward velocity is proportional to a large induced drag.
The interaction between undisturbed air outside the cylindrical tube of air, and the downward-moving cylindrical tube of air occurs at the wing's tips, and can be seen as wingtip vortices."
So, Soren. A U-2 has a 103 ft wingspan, an aspect ratio of 10.6. Is your thesis that the smaller 'stream tube' of the F-14 as evidenced by either the 38 ft swept wing or 64 ft extended wing is superior in efficiency to the U-2?
Would you further advance that induced drag of the U-2 is greater? What opinion would you care to advance regarding L/D of the antiquated, non computer controlled, wing of the U-2 in contrast to the F-14?
Would you say that the tip vortex strength of a U-2 is greater than the F-14?
Take the arguement in the opposite direction - compare the 'smaller stream tube U-2' to the B-29 which had a higher AR and 40% MORE span than the U-2. What are your conclusions about the efficiency and the relative strength of the tip vortices - which one would you prefer to land behind?
Last, the wing span difference between a U-2 and a B-17 are only a couple of inches off. What do you want to say about the same stream tube and it's validity to the wing efficiencies?
Oh but then again the above is just opinion based, not "facts" like you rely on.
Soren, which of the three examples makes sense to you and which one do you wish to base your 'stream tube' thesis on? BTW for comparable span and geometry lift loading is a better determinant for judging relative tip vortex strength
I bow humply to your superior knowledge.
Okay, let's take a look at the two radar systems in question:
AWG-9: For it's time, the most powerful airborne radar system in the world; able to track up to 24 targets at a time, and launch missles at 6 of them at one time. Range well in excess of 100 nm. However, it is based and built using analog technology from the '60's, was maintenance intensive, and was completely incapapable of being used in an a2g mode (which is why the F-14D got the AN/APG-71 digital multi-mode radar); could probably best be compared to the RP-25 Smerch radar on the later MiG-25 interceptor.
AN/APG-63(V)3: Completely digital, multi-mode AESA technology, classified range (the broadly similar radar in the F-22, the AN/APG-77, has a range "in excess of 320 miles"), multiple LRU's, can be used interchangably in both a2a a2g modes, LPI frequency-hopping (the AWG-9 couldn't do this).
Yeah, opinions and guesswork in your opinion..
Even when I've made it clear that while I know a lot on the subject I am no expert in airplane aerodynamics, you're still more busy hammering at me, patronizing me and calling me names, instead of actually trying to figure out what it is I'm saying (Incase my terminology is incorrect) and then providing what you know after that. No, you just have to throw in the patronizing remarks as well pull up out-of-context phrases from old arguments to make it look like you're the sh*t and I'm stupid even to be debating with you.
I usually hammer you only when you advance obscure references to aero theory completely out of context and frequently wrong.
I truly wish one could have a friendly FACT based debate with you Bill, but it has been impossible for me so far, even when letting you know that I'm noting every word you write as educated information or guesswork, cause you completely ignore what I write, even purposely misunderstanding some of the clear cut out fact based information I provide. Now I'd love to be educated when wrong, but I can do without being ridiculed for doing nothing but reading what you write and responding with what I know.
Afterall I think everyone everywhere should remember that unless you're directly involved with the subject at hand then you ONLY know what you've read about it. Math is fact based, but again you only know what you've read about it.
Fine, since you're of the opinion I have nothing to contribute with I'
ll shut up.
So, Soren. A U-2 has a 103 ft wingspan, an aspect ratio of 10.6. Is your thesis that the smaller 'stream tube' of the F-14 as evidenced by either the 38 ft swept wing or 64 ft extended wing is superior in efficiency to the U-2?
Would you further advance that induced drag of the U-2 is greater? What opinion would you care to advance regarding L/D of the antiquated, non computer controlled, wing of the U-2 in contrast to the F-14?
Would you say that the tip vortex strength of a U-2 is greater than the F-14?
If you want to understand why we don't have friendly debates, look in the mirror as well as your posturing.
That is correct Soren.
If you want to understand why we don't have friendly debates, look in the mirror as well as your posturing.
You did not need to explain that to me. I was being sarcastic.
Okay, let's take a look at the two radar systems in question:
AWG-9: For it's time, the most powerful airborne radar system in the world; able to track up to 24 targets at a time, and launch missles at 6 of them at one time. Range well in excess of 100 nm. However, it is based and built using analog technology from the '60's, was maintenance intensive, and was completely incapapable of being used in an a2g mode (which is why the F-14D got the AN/APG-71 digital multi-mode radar); could probably best be compared to the RP-25 Smerch radar on the later MiG-25 interceptor.
AN/APG-63(V)3: Completely digital, multi-mode AESA technology, classified range (the broadly similar radar in the F-22, the AN/APG-77, has a range "in excess of 320 miles"), multiple LRU's, can be used interchangably in both a2a a2g modes, LPI frequency-hopping (the AWG-9 couldn't do this).
Hi Sod
I dont know where Soren was going with his comments, but i would just like to point out that the AWG-9 was not the latest in F-14 radar development, just as the AN/APG-63 was not the first word in F-15 radar development. As you point out, the radar in use in the F-14Ds was the APG-71
(If you wanted to compare the AWG-9 with its F-15 contemporaies, ie the radar fitouts to the early eagles of the 1970s, I think you would find the Hughes radar to be far superior to that fitted to the early Eagles. If you wanted to compare the late 80s versions of the Tomcat (the F-14Ds) with the equivalent time period Eagles, I think you would again find the Tomcat to possess superior radar again. Its just that the Eagle has been stretched to the "super eagle" that explains its later superiority over the 'cat electronic fitouts.....
Nope, that's not at all what I'm saying. The U-2's wing provides more lift less drag pr. area than the F-14's, the higher AR makes sure of that. It's the very same thing that makes the F-14's wing more efficient than either the F-15's or F-16's.
But the AR of the U-2 is less than the B-29 example I just gave you... and you just skipped right on by that one. The B-29 has a higher lift loading (or wing loading if you wish) - so it definitely contributes more to the tip vortex. And the B-29 has a larger 'stream tube' per your definition. By your implication of what you think a stream tube is...
In level flight, the U-2 lift loading for max TO is 40#/ft sq, a B-17 with exactly the same span on normal loaded condition of 54K (not max) has a 1 g lift loading of 36#/ft sq. They both have exactly the same 'stream tube' from your quote. The B17 has more lift per area than the U-2 because it takes less lift per ft sq than the U-2. One (B-17) will climb to 32-35000 feet. the other will get to 70000+.
The B-17 AR is 7.6, the U-2 AR is 10.6.
And your answer for the most efficient wing is?
BTW 'more lift per area' corresponds to a higher CL, less drag per area corresponds to a lower CD for the wing- for the same angle of attack.
Bill have you at all been reading what I write ???!
Here is what you wrote but I will separate it into parts
" "Aspect ratio and planform are powerful indicators of the general performance of a wing, True although the aspect ratio as such is only a secondary indicator. All things being equal including span and airfoil - NOT true- the lift loading is much more contributory to tip vortex and efficiency
The wingspan is the crucial component of the performance. This is because an airplane derives its lift from a roughly cylindrical tube of air that is affected by the craft as it moves, and the diameter of that cylindrical tube is equal to the wingspan.
From the standpoint the 'actual' flow properties of the airflow about the wing body, this is NOT true. The actual boundary layer to freestream unperturbed flow stream distance is FAR less than the boundaries of the 'span diameter cyclinder' - but lets suppose you are trying to make a point
Thus a large wingspan is working on a large cylinder of air, and a small wingspan is working on a small cylinder of air. Say the large wingspan is working on a 'span of freestream air' nearly equivalent to the span of the wing'. What is truly important in this analogy is the strength of the lifting line giving the spanwise section lift and drag characteristics - the strength of which is the required lift distribution required to sustain flight. The 'circulation' translates to bound circulation along the Lifting Line. The strength of this Bound Circulation is directly related to the strength of the tip vortex.
The smaller cylinder of air must be pushed downward by a greater amount in order to produce an equal upward force; See above. Having said that it is TRUE that for an equal load for the same airfoil, for less span and equal AR, that the lift per area is going to be higher for the smaller span - and consequently a stronger tip vortex. With those same conditions the 'efficiency of the lower span wing' given same AR, but higher wing loading will be less efficient.
the aft-leaning component of this change in velocity is proportional to the induced drag. Therefore a large downward velocity is proportional to a large induced drag."
The 'large induced drag for a/c with same AR and span and airfoil will then be primarily and proportionately linked to lift loading'. A tip vortex has both rotational velocity as well as a down velocity component - the strength of which is directly related to the Circulation about the lifting line.
Now make your case once again for why the F-14 in swept wing config for speeds > say .8 M become superior when the Lift loading and the AR and T/W is significantly less than the F-15 and F-16 (and F-18)
Yes Soren. You have misunderstood the context. A wing is more efficient if the amount of total lift (force), at the same angle of attack, is greater for the same area, as the wing being compared.
Tell me do you understand what this means:
"Aspect ratio and planform are powerful indicators of the general performance of a wing, although the aspect ratio as such is only a secondary indicator. The wingspan is the crucial component of the performance. This is because an airplane derives its lift from a roughly cylindrical tube of air that is affected by the craft as it moves, and the diameter of that cylindrical tube is equal to the wingspan. Thus a large wingspan is working on a large cylinder of air, and a small wingspan is working on a small cylinder of air. The smaller cylinder of air must be pushed downward by a greater amount in order to produce an equal upward force; the aft-leaning component of this change in velocity is proportional to the induced drag. Therefore a large downward velocity is proportional to a large induced drag."
If you do, then why are you asking me these questions ?
Well, you certainly are an arrogant fella, I'll give you that!
You are calling me 'arrogant'?? - interesting
Oh I am so sorry for being offended when being called stupid, that is so wrong of me, I apologize Bill. You are in your full right to start an argument by calling others names, it is my job to take full responsibility for that, I mean I after all provoked you into it right ?