J-20 5th Gen Fighter Thread V

[vesicles]

They must be flying these beauties very aggressively. We don't usually see a lot of pictures with other kinds of fighters (J-10, J-11, etc) showing so many vortices. Within the past few days, at least half of pics that we've seen got the J-20 with amazing vortices.

So my question is that have they been flying the J-20 extra aggressive, or the J-20 has been designed to generate vortices? Maybe both?

 

[dingyibvs]

They must be flying these beauties very aggressively. We don't usually see a lot of pictures with other kinds of fighters (J-10, J-11, etc) showing so many vortices. Within the past few days, at least half of pics that we've seen got the J-20 with amazing vortices.

So my question is that have they been flying the J-20 extra aggressive, or the J-20 has been designed to generate vortices? Maybe both?

I think they just don't show the other fighters flying aggressively very often.

 

[Quickie]

They must be flying these beauties very aggressively. We don't usually see a lot of pictures with other kinds of fighters (J-10, J-11, etc) showing so many vortices. Within the past few days, at least half of pics that we've seen got the J-20 with amazing vortices.

So my question is that have they been flying the J-20 extra aggressive, or the J-20 has been designed to generate vortices? Maybe both?

It should be designed as such. As an example, I don't recall the J-10 or the J-11 generating as strong as the wingtip trail as the J-20 in this pic during a what seem to be a not so aggressive turn maneuver.

 

[siegecrossbow]

It should be designed as such. As an example, I don't recall the J-10 or the J-11 generating as strong as the wingtip trail as the J-20 in this pic during a what seem to be a not so aggressive turn maneuver.

Isn't wing-tip vortice detrimental to lift generation? I've read somewhere that aircraft designers should reduce them as much as possible.

 

[Air Force Brat]

Isn't wing-tip vortice detrimental to lift generation? I've read somewhere that aircraft designers should reduce them as much as possible.

NAW! whut??? The tremendous visible turbulence is the picture of the "tremendous" amount of lift that is actually being generated, they are almost always observed on Fighter aircraft pulling a little G. (an aircraft in a 60 degree bank it always pulling exactly 2 G's) the first aircraft blowing wing tip vortices that I ever observed was a C-130 that made a fast pass over our house at about 500ft, and then promptly rolled into a + 60 degree bank.

In answer to Vesicles question they are "beating" on these poor little chicks. We are seeing the evidence in the tremendous "contrails" being generated due to moisture/static discharge as they are carrying more than a bit of speed and then pulling very hard and increasing the angle of attack to near max. This increases the positive pressure or "lift" under the wing and its racing to equalize that pressure by escaping over the side/top of the wing tip at its very first opportunity.

So if we are NOT seeing airshow prep??? I will be a "monkeys uncle". Last year we saw the J-31 at Zuhai, if the Chinese don't showcase at least 1 fifth gen this year, people will drive you nuts with questions and doubt about the Chinese program, specifically the J-31, but bleeding over into the J-20 Chengdu program. I think she will be there, I have my doubt about the J-31/FC-31, but I am still hopeful.

Gents I really would love to see some of this more advanced aerodynamic discussion/pictures moved over the "aerodynamics thread", that thread is under utilized, and I believe if you would re-read/read some of the old posts, you would get a good grasp of aerodynamics, and what a wonderful airplane the J-20 really is?

Back to you siege, airliners often wear "winglets", or vertically upswept wing tips to maximize lift/efficiency and put it to "work". The J-20 and other fighters aren't out to get good "gas mileage" they are "RACING" vehicles out to maximize high performance.

These aircraft do indeed generate more vortices off the vortex generators inboard on the wing to increase lift, but the vortices blowing off wing tips are gone baby!

 

[Air Force Brat]

It should be designed as such. As an example, I don't recall the J-10 or the J-11 generating as strong as the wingtip trail as the J-20 in this pic during a what seem to be a not so aggressive turn maneuver.

That's fuel venting off the upper tip, he has the flapperon on that side deflected downward to roll the aircraft to the left, the nose is up, indicating that he is carrying some speed and has already "pitched" the aircraft nose up aggressively and is equaly aggressively "rolling" the aircraft to the left. If he had rolled to the right while performing the mirror image of that maneuver, the fuel would be venting out the left tip vent.

You will notice the vortex is "very tight", indicating to me that he is probably at least 250+ knot IAS, possible as high as 450+ knots IAS.

 

[Quickie]

That's fuel venting off the upper tip, he has the flapperon on that side deflected downward to roll the aircraft to the left, the nose is up, indicating that he is carrying some speed and has already "pitched" the aircraft nose up aggressively and is equaly aggressively "rolling" the aircraft to the left. If he had rolled to the right while performing the mirror image of that maneuver, the fuel would be venting out the left tip vent.

You will notice the vortex is "very tight", indicating to me that he is probably at least 250+ knot IAS, possible as high as 450+ knots IAS.

That looks like vortex trail to me. Fuel contrail is more detached and cloud like. AFAIK, the J-20 vent its fuel through its engine nozzles.

 

[dingyibvs]

It should be designed as such. As an example, I don't recall the J-10 or the J-11 generating as strong as the wingtip trail as the J-20 in this pic during a what seem to be a not so aggressive turn maneuver.

Not a J-11, but here a Su-35S at an airshow with a lot of wingtip vortices.

 

[Deino]

That's a photoshopped image of a Raptor !

Please, Log in or Register to view URLs content!

 

[Quickie]

Not a J-11, but here a Su-35S at an airshow with a lot of wingtip vortices.

That is smoke contrails from the wingtip dispensers.

That is smoke contrails from the wingtip dispensers.