Throttleable Solid Propellant Ramjet

[bobbymike]

From Space Daily - Space War

Aerojet Demonstrates NextGen Solid Ramjet Fuel

by Staff Writers
Sacramento CA (SPX) Aug 12, 2010

Aerojet has announced that it has successfully tested an advanced solid ramjet fuel in an engine ground test. The fuel is being developed to provide long-range, high-speed capability for the U.S. military and potentially for the future USAF/Navy Joint Dual Role Air Dominance Missile (JDRADM). Ramjet engines have historically used liquid fuel which mixes with atmospheric air in order to provide thrust at high speed. However, for tactical missiles, the military services have expressed interest in a storable solid fuel.

In order to meet this need, Aerojet developed the world's first throttleable solid-fueled ramjet for the U.S. Navy GQM-163A Coyote missile target starting in the year 2000. Since that time, Aerojet has been developing a family of advanced formulations called AerGen(tm) fuels with properties suitable for a tactical missile ramjet engine. The fuel burns very efficiently, resulting in more delivered energy and reduced visible exhaust.

The ground testing was conducted at Aerojet's Airbreathing Test Facility located in Orange County, Va. A full-scale engine was tested at conditions simulating high-altitude, high-speed flight. "Our airbreathing propulsion business represents cutting-edge technology aimed at future military requirements," said Aerojet Vice President and Deputy to the President, Dick Bregard. "Aerojet is proud to demonstrate our commitment to advancing our country's military capability through this innovative ramjet fuel research."

 

[bring_it_on]

Anyone have any half decent video of the Coyote. The only one I could find is here -

http://lkal32.blogspot.com/2012/04/closer-look.html

 

[ouroboros]

Uh, so is this just intake choking a conventional solid fuel ramjet to provide a measure of throttle control, starving the engine, or are they somehow pumping powdered solid fuel?

 

[Sferrin]

Anyone have any half decent video of the Coyote. The only one I could find is here -

http://lkal32.blogspot.com/2012/04/closer-look.html

That's one smokey motor.

 

[KJ_Lesnick]

Fascinating

 

[bring_it_on]

Uh, so is this just intake choking a conventional solid fuel ramjet to provide a measure of throttle control, starving the engine, or are they somehow pumping powdered solid fuel?

The best explanation I could find was from the Meteor literature. The Meteor uses the same principle..

The principal powerhouse of the motor is a gas generator sub-assembly containing an oxygen deficient composite propellant which when combusted produces fuel rich combustion products which are then mixed with ducted air in the ramcombustor chamber. During missile flight the supersonic air is compressed by deceleration in the intake system and allows efficient combustion and thrust generation. The incorporation of high energy ingredients in the gas generator propellant leads roughly to a threefold increase in range of the ducted rocket compared to a conventional solid rocket propulsion system.

The pressure dependant burning rate propellant when combined with a gas generator control valve allows thrust modulation by throttling of the gas generator. The gas generator control system allows the generation of a variable thrust which in-turn enables a highly flexible missile mission envelope. The ramcombustor chamber also incorporates an integrated nozzleless booster to accelerate the missile to the velocity (approx. 2 Mach) where propulsion can be transitioned into full ram rocket mode.

Bayern-Chemie is a world leader in throttleable solid propellant ram rocket technology covering

Air intakes for various Mach-ranges
Intake closure and port cover mechanisms
High energy (boron filled) gas generator propellant
Gas generator throttleable control valve technology
Nozzleless Boost motor (reduced smoke) technology
The advantages offerered by solid propellant ram rocket technology include

High range of propelled flight
High average speed
Flexible mission envelope achieved by the use of active thrust control
Wide operational envelope from sea level to high altitude
Relatively simple design
Logistics comparable with conventional rocket motors
The knowledge of `Ramjet` propulsion technology that BAYERN-CHEMIE have gathered over several decades opens up a tremendous range of new dimensions for the performance of missile systems.

For missile missions where a combination of high speed, manoeuvrability and range is mandatory, then a solid fuel, variable flow ducted `Ramjet` will be the propulsion system of choice.

Missiles similar to METEOR could also be adapted and developed for air/ground, ground/air or ground/ground missions.

Bayern-Chemie has already started to work on much more sophisticated future concepts that include hypersonic `Ramjet` propulsion systems. One such is the CVS401 PERSEUS, a visionary Naval and Land Attack Weapon System of MBDA.

http://www.bayern-chemie.com/ramjet.htm

That's one smokey motor.

That is what I wanted to check through a better quality video

I guess it depends all upon the solution..Aerojet supplied the variable flow technology for the T3 missile to at least one competitor (Raytheon), I doubt that a BVR missile would be this smokey in the ramjet phase of flight since its a different technology from the Coyote which was the first of its kind.

http://www.rocket.com/article/aerojet-successfully-demonstrates-next-generation-solid-ramjet-fuel

https://www.rocket.com/t3-variable-flow-ducted-rocket-vfdr