New J-10 thread II

[Londo Molari]

Originally Posted by AmiGanguli

If the force there were strong enough to damage the plane, then that would imply tremendous aerodynamic resistance. So much that nobody would ever use square intakes close to the body.

They're primarily an aerodynamic feature.

Of course there is aerodynamic resistance. There is aerodynamic resistance in all planes. Thats why most fighters can't go past Mach 2.5. This doesn't mean that aerodynamic resistance will stop the J-10 from flying. It just means that after prolonged use, the air pressure in that spot will stress and warp the airframe, resulting in permanent damage. It could even rip the plane apart in mid-flight 5 years down the line. So thats why the support beams are necessary.

It can't possibly be an aerodynamic feature. How can vertical bars possibly enhance the aerodynamic performance of the fighter? Aerodynamic features manipulate windflow around them for improved performance and control. These bars just hold the aircraft together. I think the Eurofighter also has similar support structure, but its hidden right in the centre, not visible on the sides. The F-16's airframe seems strong enough not to need it.

[AmiGanguli]

It's conceivable that the pressure might damage the plane over time without the bars (although I'm skeptical of that), but the bars don't fix that by providing extra support. They relieve the pressure so that support isn't necessary.

I'm not sure what I can say to convince you, but it just wouldn't make sense to add something that hurt the aerodynamics rather than just reinforcing the intake.

[Londo Molari]

Originally Posted by AmiGanguli

It's conceivable that the pressure might damage the plane over time without the bars (although I'm skeptical of that), but the bars don't fix that by providing extra support. They relieve the pressure so that support isn't necessary.

How exactly do vertical bars relieve pressure that builds up between the engine intake and the cockpit?

I admit I'm not an engineer or an expert. But if pressure that builds up in there, I would expect it to force apart the engine intake downwards, and the cockpit upwards, and thats when those vertical bars could hold them in place strongly.

Originally Posted by AmiGanguli

it just wouldn't make sense to add something that hurt the aerodynamics rather than just reinforcing the intake.

Exactly. It doesn't hurts the aerodynamics. Its too small to create significant drag. But it does reinforce the intake.

[Infra_Man99]

I think what the guys are saying is that those bars do not hold up the intake. They smooth out air flow to relieve air pressure that builds up in that tight spot to MINIMIZE WEAR AND TEAR on the airframe.

The J-10 could probably do without those bars, because the air intake looks a lot more sturdy than the canards and other jets' horizontal stabilizers. With the bars, the J-10's airframe will LAST LONGER, and this is good for the cut-throat Chinese air force.

[crobato]

Actually what the compressed air pressure between the intake lip and the fuselage is to cause the lip to oscillate, or a shaking vibration movement.

This is not something that KANWA implied before that the intake tunnel was too heavy and therefore required additional supports. This mean support against weight, not *hold* against air pressure. These two are very different when it comes to engineering.

[Londo Molari]

aaaah, that clears it up

[Infra_Man99]

Crobato:

Let me reword what you said to make sure I understand you.

Are you saying the bars are for stabilizing the intake during high-pressure maneuvers, and that Kanwa was wrong for saying the bars are for holding up an overly heavy intake?

[crobato]

Not for high speed maneuvers but for high speed flight. And its not for stabilizing, but for dampening harmonics around the inlet lip, as well as changing diffusing the air pressure in the gap to the sides. Its not for supporting additional weight like Kanwa said.

[sumdud]

Build up of pressure? What about loss of pressure right over the lip? The pressure of the air when entering this lip area is going to be low due to the 2 surfaces that are constantly close together. (Look at ships refueling each other, you can't put them less than 150 ft apart or they'll kiss.) And I am surprised that China didn't try another method like that on the Typhoons..

[Infra_Man99]

Crobato and Sumdud:

It would make sense that the bars are there for BOTH high pressure and low pressure.

Anyhow, I believe these terms are similar:

Stabilize = dampen
High pressure ~ vibration (high pressure or high friction results in vibration)

The Eurofighter Typhoon has a close, form fitting lip. The intake is divided into two sections by a major column for the two engines. The F-16 has a rounded intake that is somewhat form fitting. Inside the intake is a long, thin bar down the middle. J-10 has a rectangular intake with 3 small bars on each side. The intake is more separated from the rest of the jet's body when compare to the Eurofighter Typhoon and F-16. They seem to be different means to achieve the same thing.

[unknauthr]

Another mainstream news outlet - this time Forbes magazine - appears to have picked up on the "China is selling J-10 fighters to Iran" story.
http://www.forbes.com/businessintheb...31beltway.html

Once a wild rumor like this gets started, its hard to kill. All this from one Russian news article of questionable origin.

So here's my theory on how and why this rumor began:

Iran may have been trying to leverage a better deal for Su-30 fighters from Sukhoi, by spreading rumors that they are considering a buy of the J-10 instead.

Iran has been negotiating for the Su-30 for quite a while now. Either the US is pressuring Moscow not to make the deal, or perhaps the terms of the deal have not been to Tehran's liking. Either way, a little competition just might give the Russians an incentive to close on a sale.

[Infra_Man99]

In my opinion, this is how the false Iranian J-10 news got started:

1. Israel has been sending representatives to China to convince China to side against Iran. China clearly says "No." Read Chinese news for proof.

2. Israel visited Russia and had telephone talks with Russia to convince Russia to side against Iran. Russia said "Maybe." Read Russian news for dates of these meetings.

MY GUESS: Israel wants to change China from "No" to "Maybe," so Israel figures that if it spreads negative news about a military deal between China and Iran, Israel can put a spot light on the relationship between China and Iran, which will reveal that China and Iran are on friendly terms, so other nations (i.e., the US and EU) will pressure China to take a harder stance on Iran.

3. Israel visits Russia. Then Israeli tells Israeli news and Russian news that China is selling J-10 jets to Iran. See Russian news for these visits.

Now Israel is trying to spread the false news to the US and EU, hence Forbes.

4. As of late October to early November, Israeli Deputy Prime Minister and Minister of Foreign Affairs Tzipi Livni met with China to support new sanctions against Iran. China has rejected the unwarranted punishment again.

Because of this recent rejection of Israel plans by China, there might be more Israeli false news or biased news about China arming Iran to get international nations (US and EU) to pressure China to side against Iran.

Anyhow, my point is that the J-10 news is most likely false and just a silly Israeli political tool. Israel can better work with China by not making false rumors about China, Iran, and the J-10 jet (or bad news).

[crobato]

My opinion is simply bad and incompetent journalism. The lack of independent press in Russia for decades meant whatever independent news organization they have now, was practically learned overnight. That means, unlike the West, they have not been honed or learned through decades of the hard lessons in proper editorship and journalism, such as fact checking before printing.

Just remember in the past how many false arms sales the press has reported, including one last July allegedly that the Russians are going to sell loads of Su-30s to Iran.

[challenge]

a model of J-10 and FBC-1 appear in iranian airshow,indicate China do tempt to sell the aircraft to iran.but it equally puzzle when iran has a lot of ex-iraqi jet in store.and russia willing to offer iran mig-29 and su-27, unless it is diplomatic ploy by the iranian playing chinese card against russian for better deal.

[crobato]

FC-1 was also shown in Singapore air show before, does not mean they're trying to sell FC-1 to Singapore. Su-35 gets to appear in Paris air show, does not mean they're trying to sell Su-35 to France. So that logic is not very good.

One reason why it surprises me about the whole thing is that the Iranians had a negative view of the J-7s they bought, and thus view Chinese products in a derogatory light. They are not likely on their own accord to buy something from China unless they can be fully convinced that quality issues will be turned around.