Aerodynamics thread

[latenlazy]

This is only blah blah blah, the total lift of a configuration is what counts, it does not matter it has delta or no delta wing or canards or not, twin fins of not

And how do you determine total lift? (Hint, it has something to do with whether you have delta wings or not, canards or not, etc, your engine, and the specific flight conditions). There's a reason why an excruciating amount of research is put into wing design, and why different planes have different kinds of wing.

more blah blah blah, i asked you why, it is very easy to say aerodynamic optimization, but is harder to say in specific why, you are dodging the question why?

I know simply you do not know and have no idea what really are LEXs

If you know more specific reasons feel free to share. I readily admit I'm not an expert on aerodynamics, and am always ready to learn more.

If you just want to pay rhetorical games though I'd readily point out you've consistently avoided refuting or answering my main point, which is that shapes and features DO MATTER in performance and that as designs get more complex and our understanding of fluid dynamics improves that will mean designs which may have to strike fewer compromises (this goes back to how delta canards employ vortex lift to mediate some of the low speed penalties for delta wings, but it also goes to things like how the PAK-FA uses LEVCONS to adjust the strength and burst of vortices over its wings). If you really want to have an earnest discussion you should probably address that point with more than a force diagram, because as mentioned earlier lift force is determined by other factors that relate to fluid dynamics and that force diagram tells us nothing about what that lift force is or how it's determined.

 

[F-15]

OK, if you have ever done simulations/modeling, you would know that theoretical work has its flaws, serious ones. In order to get the math to work, i.e. solving the equations, theoreticians have to make assumptions. Most of the time, these assumptions do not work in the real world, like inventing multiple universes or extra dimensions.

Do you know what is model do not you? Model are representations of reality, but not the reality it self, you whole speech that by the way was way too long and boring honestly, goes to fail to say something very simple, if a mathematical model fails, is because the model is not correct, so then you have to modify the model, of course experimentation validates the model, however the language is math, not some obscure magical reality.

To put it simple, new equations are made when the original ones cannot explain reality and the model falls short, in example Maxwell equations that fixed some of the short comings of the Gauss, Ampere and Faraday`s laws.

What you are simply hiding is the fact, the whole language of engineering and science is Math, no modern theory is purely theoretical, since the scientific method demands experimentation.

Now no modern engineer will express his words with pure human language, you need Math, once the Math is clear, the theory can be expressed with words.


Here you have guys, how only say, due to their ignorance, that Math is not important, experimentation is everything, give me a break, engineering`s language and only real tool is math.

 

[F-15]

And how do you determine total lift? (Hint, it has something to do with whether you have delta wings or not, canards or not, etc, your engine, and the specific flight conditions). There's a reason why an excruciating amount of research is put into wing design, and why different planes have different kinds of wing.





If you know more specific reasons feel free to share. I readily admit I'm not an expert on aerodynamics, and am always ready to learn more.

.

You said aerodynamic optimization, but you can not explain it, that is blah blah blah, if you can tell me how it really works, then you can address if it was o not for aerodynamic reasons or stealth or what ever, but what you are doing is only blah blah blah since you do not even really know how does it work

 

[solarz]

Do you know what is model do not you? Model are representation of reality, but not the reality it self, you whole speech that by the way was way too long and boring honestly, goes to fail to say something very simple, if a mathematical model fails, is because the model is not correct, so then you have to modify the model, of course experimentation validates the model, however the language is math, not some obscure magical reality.

To put it simple, new equations are made when the original ones cannot explain reality and the model falls short, in example Maxwell equations that fixed some of the short comings of the Gauss, Ampere and Faraday`s laws.

What you are simply hiding is the fact, the whole language of engineering and science is Math, no modern theory is purely theoretical, since the scientific method demands experimentation.

Now no modern engineer will express his words with pure human language, you need Math, once the Math is clear, the theory can be expressed with words.

Here you have guys, how only say, due to their ignorance, that Math is not important, experimentation si everything, give me a break, engineering`s language and only real tool is math.

Nobody said the Math isn't important.

 

[F-15]

You must be a fan of Descartes. Too bad Science is more of a fan of Locke.

Ask an engineering job without math, i bet you won`t get it, Math is not theoretical, in fact its main goal is practical, since any calculation in manufacturing from production optimization will use math ie Differential calculus, even a modern economist rely in math.

Aircraft engineering is basically math, only here people say things like canard will make it superior, any aircraft requires math just to fly not sterile discussions and by the way stupid discussions about it has canards it will fly, the whole fly by wire is basically math applied.

 

[thunderchief]

Of course J-20 is faster and more maneuverable than J-10. For one, J-20 is designed to super-cruise, whereas J-10 is not. For another, J-20 combines multiple vortex lift unlike the J-10, allowing J-20 to attain higher lift coefficient and more maneuverability.

Of course it is not. With current engines, J-20 is probably slightly faster then J-10, but wing loading is absolutely lower on J-10 . Also, with current engines J-10 has advantage in T/W . Therefore, I'm absolutely positive that J-10 would beat J-20 in close combat .

Generating fraction of lift is still generating lift. Also, canard works with zero angle-of-attack, which is shown very clearly in the second graph on the left column. Regardless, canard generates lift, unlike what some have claimed otherwise.

Therefore, you admit that wing still generates most of the lift And btw, other fighters also use vortex lift, so any advantage from advanced could be just a "fraction from the fraction" to use your terminology.
Also, diagram shows that canards do not generate additional lift in normal flight (AoA close to zero), for obvious reasons.

Of course. The diagram doesn't show something that is not true. For a given lift coefficient, canard layout experiences less drag than a layout without canard. This can be seen in the third graph on the left column.

Diagram shows that with canards you could have better lift, but with more drag . Purpose of canard is exactly that - convert more of the kinetic energy (speed) into potential energy (height via lift) . Nothing more, nothing less.

Energy is transferred to the vortex, not loss. Since the vortex is generated upstream of the wing, the energy has the opportunity to be transferred back into the aircraft, and this transfer contributes to lift. The process is quite efficient and the fighter doesn't lose much energy.

Energy transferred to vortex is lost to plane (less kinetic energy) . Purpose of capturing vortex is exactly that - to get part of that energy back to plane . Energy efficiency is a tricky question in this case, but I doubt it could be better then 80% .

 

[latenlazy]

You said aerodynamic optimization, but you can not explain it, that is blah blah blah, if you can tell me how it really works, then you can address if it was o not for aerodynamic reasons or stealth or what ever, but what you are doing is only blah blah blah since you do not even really know how does it work

I said it COULD be optimization. If I claim that we don't know how the J-20 actually performs because we don't know the specifics of the design unless we stick it into a simulation, wind tunnel, or flight tests and then claim to know with absolutely certainty why they made design changes I would be lying about something. You seem to be suggesting that you know more though so pray tell, explain the specifics.

 

[F-15]

Of course it is not. With current engines, J-20 is probably slightly faster then J-10, but wing loading is absolutely lower on J-10 . Also, with current engines J-10 has advantage in T/W . Therefore, I'm absolutely positive that J-10 would beat J-20 in close combat .

What the engineer guy and you are saying has similarities, both of you are right in a way.

since the total lift is what matters, canards or LEX have double function, lift and vortex generation.

ie Su-33 and F-18E, in both aircraft they needed extra lift, in the F-18E, the increased area of the LEX is to increase total lift at cruise flight because the F-18E is heavier than the original F-18A/C, so it needs bigger wings and LEX to offset the need for higher lift force.

However that implied blunted LEX on the F-18E, they are still for vortex generation but are not as ideal as the ones seen in the earlier F-18C.

everything has drag penalties, but at the end of the day the best turning fighter is the one with the better lift and higher thrust, it does not matter it has canards or not, it only matters if it is optimized enough for its weight and size

 

[F-15]

The pray tell, explain the specifics, because we would all like to know.

Google it, do not be late and Lazy, the answer is pretty simply but i said to you google it the clue is the LEX studies of the F-16

 

[latenlazy]

Aircraft engineering is basically math, only here people say things like canard will make it superior, any aircraft requires math just to fly not sterile discussions and by the way stupid discussions about it has canards it will fly, the whole fly by wire is basically math applied.

Is that what this argument is about? Because if you review what I've actually said I made no claim of the sort.