Forum: Technology

Hi, I was wondering that Thrust Vectoring changes the direction of the Thrust Nozzles of fighters, then I was thinking, doesn't the JSF use it?

For instance, I saw a video of a JSF changing it's entire Thrust Nozzel 180 Degrees to do a Verticle Take Off! Does the Harrier use the same system?

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Quote:

Does the Harrier use the same system?

Not the same but similar. Harriers have four ejector nozzles, two on each side of the fuselage. These rotate through a range of straight back (90 deg) down to slightly forward (5 deg) to vector the thrust for S/VTOL operation.

The JSF design uses the single aft nozzle and a forward downward facing lift fan, driven off the front of the turbofan engine.

F-35 uses the system developed by lockheed that Habu2 already mentioned. The Boeing F-32 built on the original Harrier system in which 4 nozzles, 2 off the cold half of the engine and 2 off the hot are used in symetrical vectoring.

They also use a puffer system in the wings and tail on the harrier for control in the hover, where as the F-35 uses the main rear nozzle to swivle and give a gentle nudge in the direction the pilot wants to go.

As for in flight thrust vectoring, you could call it that. There is actually a technique called "Viffing" that the Brits used in the Falklands campaign suprised the hell out of several Argentinian pilots.

Lawman, does the X-35 design not use 'puffers'? I assumed it did but don't really know...

180 degrees rotation would be great for warming up the ground crew. Laughing

Last edited by Wildcat on Mar 13, 2004 - 01:07 PM; edited 1 time in total

Habu2, I checked in CodeOne:
There is a roll post at the end of each wing to get lateral control, each producing up to 1,500 pounds of thrust.

So when the plane is in the air, how does it change it's direction without dropping altitude when it's changing the direction of it's nozzle?

Not sure I understand your question, but when you point the nozzle downward you are doing it to replace wing lift with downward thrust (upward thrust vector).

Bilal_Khan wrote:

So when the plane is in the air, how does it change it's direction without dropping altitude when it's changing the direction of it's nozzle?

Computer control and compensation. The amount of thrust lost is marginal, the only problem is that it doesnt have quite as much menuvering authority as the puffer system. So in high wind, at sea landing conditions it could take alot more to bring it aboard ship. But all the yaw and pitch control is done threw the engine.

As you add rudder into the wind to land, (SOP) bleed air from the engine is diverted to the puffer ducts on the wing tips, you must add power to keep from descending onto the pad at a high rate. I've done it in the SIM.

I believe the correct forward nozzle position for VSTOL on the Harrier is 10 degrees not 5, for a total of 100 degrees of travel, HABU. It is used as a reverse thrust operation on conventional landings and with nozzles between 0 and 60 degrees. 60 degrees is SOP.

Forum: Technology

Thrust Vectoring... does it relate to Jump Jets?