to trow around the term “Lift-body” around like it is some fashionable word is a terribly naive way to look at things. and a wrong way to look at the problem from a fighter perspective.

hypersonic vehicles and space re-entry vehicles and research perspective? go ahead. but in fighter and transport world we do not pretend that we can seperate “body-lift” from “wing-lift”.

so this whole point is a moot point.

now if you are willing to go in technical details and speculate on the specific aspects, I am all ears.

I think our pseudo aerodynamicist-wanna-be is not very familiar with google:

Very brief introduction about this rather simple concept of lifting-body can be found here:

http://en.wikipedia.org/wiki/Lifting_body

And of cause, these “space” ships you claimed are all tested under atomosphere with low mach, appenerantly, using the lift creates by their lifting-body, it seems that the their lifting-body still work within atomsphere.

I think thats the problem with our amaterish wanna-bes, it seems that they have difficulties in understanding any simple concepts.

As for lifting-tonque? well thats very simple:

Since the lifting-pressure exerted at the body of the fighter is actually not matched magically instead it will most likely created a tonque, instead of acting like just a force straight pointing upwards at the weight center of the fighter.

Thus, when needed, the lifting-tonque created by the lifting body has to be matched by the tonque created by the controllable surfaces like the canards(for a canard-fighter) through means of flight control system, to prevent the fighter from (if) un-wanted body-rotation, get it? my rather not-very-bright boy?

Meh.. pls back that one up by something other than words!:)
There exist no other fighter design like the Flanker which produce more high-lift with the body as well as its blended wings.
And certainly much more ‘Body high-lift than the F-22.

Are you serious about this??:confused:
If you shape a wider flatter body design vs a more chubby one(F-22/F-35).. whos got the most Body(overall) high-lift?

Edit: i remember seeing a diagram ones showing the Flankers ‘gliding cure'(as if it lost all engine power).. it was no other coming near it in high lift performance.

Are you sure you compared that with the one like F-22?

Obviously F-22 get one obvious lifting-body design:

Look at its side-view, the upper half of F-22 is obivous flatter than its lower half, which creats a air-pressure forces pointing upwards, thus the lifting tonque.

Of cause high-lifting is not necessarily means better air-combat performance, it is the lifting tonque and their controlablity at high attack angle that matters, otherwise, the lifting tonque may only useful when it comes to ferry range of the fighter.

The Chinese memebers could careless about their PAK-FA whatever yet it is always the russians to despreately trying to downplay the J-20 which force our Chinese memebers to remind the Russian members that their PAK-FA is not so invincible anyway.:diablo:

I guess which indicates that the fact the actually we all know which design is far superior hence one group of people could careless about the other’s design meanwhile the other group of people are in serious denial mode and keep trying to convince themselves that theirs one are better than the other design.

Very common human mental reactions/defensive mechanisms.

But I believe pics worth thousands of words, so lets stop here, stop any PAK-FA vs J-20 posts since I bet in the end we all know the answer::diablo:

Uber advanced, latest Russian fighter, PAK-FA:

V.S.

Something that is 20 years behind the Russian techs (according to the Russian sources, hehe):

When aerodynamicist-wanna-be-s here critize J-20’s maneuverability I can only sense entertaining-ness.:diablo:

Their amateurism has betrayed their wanna-be-aerodynamicism, they don’t know they accidentally pick on the STRONGEST point of J-20’s airframe:diablo:

The confidence shown in some of our memebers here is really impressive, especially considering the fact they obviously don’t know anything remote in the area they open their mouth about.

I guess thats why they are so confident, lol.

To Franc:

I give your some other lectures on elemental aerodynamics:

The main benefit of the layout of J-20 is that it creats signficant more lifting touques for fighters at high angle of attack comparing to other aerodynamic layouts, which means the fighter would be extremely agile.

This is done by scientific research based on massive wind tunnel tests, conducted by the chief scientist and vice programme director of J-20 project, Song Wen-cong and his team (I can show you the academic research paper on this).

However, there is a drawback of this layout, which is, at high mach, the air drag of it will be higher than convential layouts.

So if engine is a concern, the fighter would not have been so big and using such a layout with a relative higher air-drag ratio.

Btw, aerodynamics is an very experiments-driven science, numerical simulations cannot offer any serious predictions, the N-S equations based models are highly immature and usually subject to extensive modifications (based on wind tunnel tests) before they can used to predict anything.

Thats why wind-tunnel tests are the primary and principle approaches in aerodynamic studies.

Based on Song’s wind-tunnel tests, J-20’s layout creates roughly 50%+ more lifting tonques for fighters at high attack angle comparing to more convential layouts.

In terms of the aerodynamic performance for fighter at high attack angle (the principle performance index for fighter during air-combat, and this is one “S” (super manuever) among the 4 “S” for a 5th generation fighter, when other factors are controlled, based on Song’s wind tunnel tests:

J-20’s layout(lifting body canards with blending strakes)>>short-distance coupling canards (J-10, Rafale, JAS-39 and MiG-1.44)> long-distance coupling canards (EF2000)>pure large strake/leading edges(F/A-18E/F, FC-1)>convetional airframe (F-22,F-35,etc).

Real world performance seems correlates with Song’s finding well:

(1) Among US military’s arsenal, seems the only one can get a F-22 (conventional layout) down is a type of F/A-18(large leading edge/strakes).

(2)USAF’s Chief of Staff General John P. Jumper claimed EF2000 (long-distance coupling canards) is more agile fighter than any of the USAF fighters he had driven.

(3)Rumors suggest, in air-combat, the French Rafale (short-distance coupling canards) beat the EuroFighter 2000 (long-distance coupling canards) easily, even through tech-wise the two supposed to be on pair.

Many of the Russian sources on China are only for entertaining purposes :diablo:

Still remeber just days before the reveal of J-20, there are still Russian sources recycling their rumors on how China want to buy their Su-35s now and will buy their PAK-FA after 2025, I am very amused by these russian news :diablo:

J-20 has a flat ventral body. So you have made a mistake in basic logical operation, deductive reasoning.

But you have made a mistake in premises too. Using space reentry vehicle body design example, assuming that’s lifting body design fitted for fighter jets.

So it could be said that using two mistakes, first in logic, second in physics, you’ve probably came to the right conclusion.

Sigh, cannot you see, of cause as a fighter, the lower half cannot be as curved as an lifting-body demonstrator, but clear enough it creates lifting, especially if you look at the rear half of the lower half of the fighter:

As for the spacecraft, it is used to show you how lifting-body design works (in that case, in a extreme way).

And of caus there are concept (extremely) lifting-body aircrafts, for instance:

The theory is quite simple here: