Home About CEC Team Systems Technology Links
Site Map Auto HEV Systems Energy Defense GCV Hybrid System Contact
Home CHP Solar Hybrid Energy Distributed Energy High Alt Power Tactical Quiet Generators Jet Engines

 

 

Turbojet Propulsion Engines

Following the experience in Afghanistan the outlook for UAVs has changed significantly from production unit potentials in the tens or hundreds to numbers in the thousands. This is largely due to the realization that even present state-of-the-art UAVs designed for reconnaissance can be used effectively in offensive roles. Notably, the use of Predators quickly modified to launch Hellfire missiles in the course of an aerial reconnaissance mission opened the door widely to new strategies based on unmanned offensive weaponry. Some of these smart munitions are to use turbojet propulsion engines. With modest additions, the company’s technical resources CEC is easily capable of developing a whole family of small, inexpensive gas turbine propulsion engines.

One application is for unmanned missiles and aircraft. This is an application that is currently of great interest to the defense industry in reference to post 9/11 military restructuring activities. Clearly, the role of the Predator in Kosovo and Afghanistan has helped shape desires for a variety of remote controlled weapon systems, many of which will need to be jet propelled or else powered for long endurance by turbo charged reciprocating engines as was the Predator. There are almost endless possibilities that could be explored which could generate needs for a wide scope of propulsion engines.

CEC is fortunate to have had first-hand exposure to UAV propulsion systems and to have access to a stable of proven turbo machine designs to draw on to cover a substantial portion of that scope. The other advantage that CEC enjoys is confidence in gas turbine design and its ability to respond quickly and imaginatively to challenging requirements. As an example of this, what is now the Capstone Microturbine was developed by CEC predecessor company, NoMac, for a hybrid Ford automotive application.  

Based on 4 existing TMS turbo charger frame sizes ranging from 3" to 7 " diameter wheels and using the adaptation scheme as diagrammatically illustrated above, a family of turbojet propulsion engines with static trusts ranging from 15 to 300 lb. can readily be created.

These may be tailored for expendable or sustained use applications with assurance of starting reliability, simplicity, and ease of installation.

CEC is capable of building these engines in modest quantities at reasonable cost, or they could be outsourced for large-scale production at very low costs.    

In the Allied Force action over Kosovo, no fewer than seven reconnaissance UAV systems saw action. They were:

  • Predator, a medium altitude and endurance vehicle;

  • Pioneer, a short-range system operated from warships;

  • Hunter, another short-range system of the US Army;

  • CL-289, a 1960's jet-powered, missile-shaped vehicle launched from a sled by a rocket booster;

  • Mirach, a similar high-speed vehicle operated by the Italian Army;

  • Crecerelle, a short-range drone deployed by the French Army; and

  • Phoenix, the British Army’s tactical UAV.

On its own, AAI of Israel has gained significant UAV experience in producing over 600 units for domestic and export use before being chosen to furnish its Shadow 200 for U.S. Army TUAV purposes.
 

Jet engines for UAVs have principally been supplied by:

  • Honeywell

  • Rolls Royce Inc.

  • Microturbo Inc.

  • Hamilton Sundstrand

  • Teledyne CAE, and

  • Williams International, Inc.

 

Loiter Attack Missiles (LAM) as used in NetFires, a typical one of the mobile munitions concepts, utilizes small jet engines. It consists of a container launch system and two weapons, the LAM and a lower-cost Precision-Attack Missile (PAM). The LAM is launched and flown to a designated area using GPS/INS navigation to look for targets with a ladar seeker. Once the LAM finds a target, aided by automatic target-recognition software, a PAM is fired to attack it. LAM can also attack high priority targets or if the LAM getting out of fuel. The less sophisticated and costly PAM would most often be used. The turbojet-powered LAM has a loiter endurance of about an hour and stays in constant contact via a two-way data link. LAM engine sizes are in the range of 30 to 50 lb thrust.

Another next-generation concept of airpower includes small aircraft capable of being launched from other UAVs or cruise missiles. These so-called "parasite" UAVs are dropped by other unmanned aircraft to loiter over a target while the mother ship moves on. Parasite UAVs would be used for dangerous missions such as bomb damage assessment, close-in jamming or even attack of soft-skin targets such as aircraft in the open on ramps and taxiways. The mother ship could service several targets to suppressed activity for up to several days. Parasite UAVs could loiter for 30 minutes as gliders or several hours if jet-powered. The mother ship would have to return periodically to its targets to launch more parasites which makes it desirable to have as much endurance built into the parasites as possible. Some concepts envision high-altitude endurance systems that deploy small loitering UAVs over hostile territory to monitor installations and possibly attack them. This would tend to emphasize fuel efficiency for parasite propulsion jet engines. This requirement would fit in well with CEC' high efficiency compressor and turbine capabilities.

Previously established markets for small jet engines are in reconnaissance and target drones which must evolve continuously to simulate new threat conditions, thereby offering new propulsion challenges. Thus reconnaissance drones evolved into UAV's at which point the lines between reconnaissance and offense were blurred when munitions were added.

There is no doubt that UAV technology will advance rapidly, stimulated by the fragmentation of national security threats into multiple international terrorist networks. Along with these advances will come exciting opportunities for innovative propulsion solutions. CEC plans diligently to pursue specific jet engine opportunities with the Defense Advanced Research Projects Agency (DARPA) as well as the U.S. Airforce, U.S. Navy and Marine Corps.