J-10 Thread III (Closed to posting)

[Deino]

Claimed to be a J-10B fuel dumping before landing...
QUOTE]

Yeppp, quite a common seight and as far as I know a unique feature on the AL-31F-series. To admit when I saw this on the J-20 for the first time it was a confirmation for me that the J-20 is also powered by an AL-31FN.

Deino

 

[Blitzo]

Yeppp, quite a common seight and as far as I know a unique feature on the AL-31F-series. To admit when I saw this on the J-20 for the first time it was a confirmation for me that the J-20 is also powered by an AL-31FN.

Deino

Not claiming the engines on J-20 are WS-10A, but just saying that J-10B 1035, the one tested with the taihang, also demonstrated the fuel dumping ability.

 

[Deino]

Not claiming the engines on J-20 are WS-10A, but just saying that J-10B 1035, the one tested with the taihang, also demonstrated the fuel dumping ability.

Upppss .... that is the news of the day to me ! Thanks for posting but I really did not know that the TH also has this feature.

Deino

 

[thunderchief]

Upppss .... that is the news of the day to me ! Thanks for posting but I really did not know that the TH also has this feature.

Deino

Almost any jet engine has this feature .

 

[Deino]

Almost any jet engine has this feature .

No, not in this solution.
The possibility to tump fuel surely yes, but it's - esp. on the F-111 - often a special vent between both engines, where the fuel is released. As far as I know no other engine however has the possibility to release the fuel from the center of the afterburner.

Deino

 

[Totoro]

while i didn't do a thorough check, i can confirm that the likes of f16, f18, f111, f15, gripen, tornado do not use such a system through the engine but eject fuel through separate lines and valve, outside the engine.

 

[chuck731]

No, not in this solution.
The possibility to tump fuel surely yes, but it's - esp. on the F-111 - often a special vent between both engines, where the fuel is released. As far as I know no other engine however has the possibility to release the fuel from the center of the afterburner.

Deino

Isn't that simply turning on the afterburner fuel system but not actually lighting the burner rings?

 

[delft]

Isn't that simply turning on the afterburner fuel system but not actually lighting the burner rings?

But if that fuel is ignited anyway, remember you are dumping it into very hot gas, ......

 

[no_name]

Russian Su-27 also dump from the centre of the nozzle. And also the fuel is not lighted in the F-111's case unless the afterburner is turned on.

Might be a noob question but does anyone know why just dumping fuel even behind a hot exhause does not seem to ignite it?

 

[chuck731]

Russian Su-27 also dump from the centre of the nozzle. And also the fuel is not lighted in the F-111's case unless the afterburner is turned on.

Might be a noob question but does anyone know why just dumping fuel even behind a hot exhause does not seem to ignite it?

I am guessing because the engine is a turbofan, which mixes hot combustion gas with cold air ducted around the engine core, the final exhaust in the nozzle is actually cooler than the flash point of the fuel vapor.

Either that, or as soon as the exhaust plume leaves the nozzle it entrain surrounding cold ambient air so efficiently that it cools to below flash point of the fuel before the fuel had time to heat up to flash.