Fluidic thrust vectoring/conformal fluidic nozzle

This design would give many advantages over current mechanical nozzle and thrust vectoring systems.
It would be much simpler, lighter and reliable than current systems and make reducing RCS easier.

Turbofan engine features, such as thrust vectoring and afterburning, require complex controls for manipulating exhaust angle and exhaust nozzle geometry. During afterburning, fuel is sprayed directly into the exhaust duct where it is burned. Afterburning dramatically increases thrust as well as exhaust temperature. To maintain constant flow and backpressure, the exhaust nozzle throat area must increase 50 to 100 percent over its normal cruise operation size.

This thrust vectoring and afterburn control system is a complex mechanical maze of hundreds of parts—hinges, seals, hydraulic actuators, bearings, flaps, etc.—that must slide, pivot, extend, and retract while maintaining tight tolerances under extreme temperature and pressure variations.

In a fluidic nozzle, effective throat area is controlled via tiny injectors symmetrically located around the nozzle throat. Depending on the configuration, injection angle, and pressure, these injectors can throttle the main exhaust stream as much as 50 percent between afterburning and normal cruise operation.

Thrust vectoring is a technique for turning an aircraft by diverting the exhaust stream using movable flaps or paddles. In fluidic thrust vectoring, a second set of injectors is symmetrically located around the nozzle flap, but the injectors are individually activated, as needed, to skew the sonic plane, the section of the exhaust where the flow reaches a speed of Mach 1.
www.memagazine.org...

The experimental demonstration of a fluidic, multiaxis thrust vectoring (MATV) scheme is presented for a structurally fixed, afterburning nozzle referred to as the conformal fluidic nozzle (CFN). This concept for jet flow control features symmetric injection around the nozzle throat to provide throttling for jet area control, and asymmetric injection to subsonically skew the sonic plane for jet vectoring.
link.aip.org.../123/502/1

Mechanical thrust vectoring involves deflecting the engine nozzle and thus physically changing the direction of the primary jet [2]. Fluidic thrust vectoring involves injecting fluid into or removing it from the boundary layer of a primary jet to enable vectoring. Although a mechanical thrust vectoring system is effective, it can be heavy, complex, difficult to integrate and aerodynamically inefficient [3]. A fluidic thrust vectoring system has the advantage of being lightweight, simple, inexpensive and free from moving parts (fixed geometry), and can be potentially implemented with minimal aircraft observability penalty.
www.geocities.com...

www.geocities.com...
www.afrlhorizons.com...
www.afosr.af.mil...
techreports.larc.nasa.gov...
techreports.larc.nasa.gov...

Very, very interesting post there! This hold lots of possibilities for more advanced, cheaper, lighter engines! Makes you wonder why nobody ever thought about before!

Turbofan engines use thrust vectoring?! ^^ hold on a second. If I remember correctly turbofan engines are used for their propeller efficiency characterists in commericial airliners. I understand the rest of this article and it makes sense for your turbojet engine, but why do they mention turbofans?

Well, the thrust reverser as used on airliners and the Tornado is a form of thrust vectoring but simplest of all, the Harriers Roll Royce Pegasus is a turbofan don't forget.

Originally posted by Aether
If I remember correctly turbofan engines are used for their propeller efficiency characterists in commericial airliners. I understand the rest of this article and it makes sense for your turbojet engine, but why do they mention turbofans?

Actually many military planes have turbofans, they're just low bypass turbofans which aren't so big as high bypass turbofans used in many civilian/cargo aircrafts.


Low bypass turbofan with afterburner:


www.aerospaceweb.org...
www.grc.nasa.gov...

[edit on 10-10-2004 by E_T]