Rolls-Royce Eyes Oil-Less Engine, Other Innovative Propulsion Concepts

Rolls-Royce Eyes Oil-Less Engine, Other Innovative Propulsion Concepts
Defense Daily 06/08/2006
Author: Michael Sirak

INDIANAPOLIS--Rolls-Royce's LibertyWorks advanced concept shop has divulged a list of novel engine designs that it is pursuing to power the Department of Defense's next-generation missiles, unmanned surveillance aircraft, long-range strike platforms and agile transport planes, according to senior company officials.

Among the concepts is a paradigm-shifting aircraft engine that uses magnetic bearings around its core. These bearings form part of the engine's integrated high-speed electrical-power generator for producing the large amounts of power needed to run the aircraft's onboard sensors and even directed-energy weapons. Equally important, they would also keep the engine's rotor aligned magnetically, thereby obviating the need for internal ball bearings and oil to lubricate and cool the metal balls, these officials said.

Removing the need for engine oil, they noted, is significant because it is one of the principal factors limiting the single-mission duration of today's aircraft engines. While the Air Force would like to fly future high-altitude unmanned sensor aircraft for periods of weeks or even months at a time, the designs of contemporary propulsion systems cannot support these lengths or would require huge tanks of oil that would weigh down the host platforms.

"The magnetic bearings offer us a way to take the oil out of the system," Phil Burkholder, the LibertyWorks' chief operating officer, told Defense Daily during an interview late last month at the company's facility here. "If you get oil out of the system, then that starts to help with persistence."

Burkholder said the company is already running laboratory testbed experiments to support this hybrid electric-propulsion design. "That doesn't mean it is ready to be put on an airplane, but it does show you that it is past the concept phase," he said.

Rolls-Royce lifted the veil on its advanced concepts division in August 2005, renaming it the LibertyWorks. The company says the division's activities are meant to add credibility to the art of what is possible in the realm of propulsion through technology development and concept demonstrations. This work is funded either alone by the company or in concert with the Air Force Research Laboratory, Office of Naval Research, Defense Advanced Research Projects Agency and other defense organizations.

As with the hybrid engine, LibertyWorks engineers have conceived the remaining concepts to offer ground-breaking innovations in the areas of affordability, endurance, speed and survivability to meet the Pentagon's emerging propulsion needs, according to company officials.

Dennis Jarvi, president of Rolls-Royce Defense North America, said while briefing reporters here the company developed the engine concepts because it felt the need to have concrete ideas that married the performance and cost attributes in different combinations.

"We can't go to a prime [aircraft developer] and say, 'Here is persistence,'" he explained. "It is hard to translate what that means. So we said we have got to have some propulsion systems that we have available that we can offer up."

In addition to responding to the DoD's needs, the LibertyWorks aims to stimulate the discussions over future aircraft designs with "neat ideas to help 'seed' the requirements," Jarvi noted.

The remaining engine concepts include derivatives of the company's F136 powerplant, which is currently under development for the F-35 Joint Strike Fighter program, to power future long-range strike platforms (Defense Daily, May 31). Burkholder said the company is investigating how to increase the time that these derivatives can sustain supersonic flight without using afterburners, a capability known as supercruise, via the use of lightweight ceramic composites inside the engines that can tolerate higher temperatures.

Another design, called the Affordable High Mach Expendable Engine, leverages the company's YJ102R powerplant that is going in the Navy's Revolutionary Approach To Time-critical Long Range Strike (RATTLRS) supersonic cruise missile demonstrator. The focus of this design, which is meant to power expendable cruise missiles to speeds greater than Mach 3, is to improve upon the YJ102R in areas like a reduced parts count to achieve cost savings, said Burkholder.

The Navy plans to fly a RATTLRS missile for the first time by then end of 2007. If successful the YJ102R is expected to set a world speed record for a supersonic engine.

The LibertyWorks is also investigating how to evolve the capabilities of the company's AE3007H turbofan engine that powers the Air Force's RQ-4 Global Hawk high-altitude unmanned reconnaissance aircraft, which is built by Northrop Grumman [NOC]. In a similar vein, it is also exploring alternate means of propulsion to power future near-space surveillance vehicles that operate in the upper fringes of the atmosphere above the Global Hawk where the air is comparatively thin.

Jarvi said Rolls-Royce has been asked if it can provide propulsion systems that can operate at altitudes up to 100,000 feet. "We are not sure that we can get there with an air- breathing engine," he said. "So we are looking at how high we can go."

"If sensors get optimized at 80,000 feet, there may not be a benefit of going to 90,000 feet," he continued. "So we are trying to work with the primes...to optimize this and do the trades between the sensor and engine capability."

A proof-of-concept demonstration of such an engine is "at least a couple of years" off, Jarvi said.

Another engine concept is the Clutched Fan Variable Cycle system that offers the advantages of hi-bypass-ratio engines for slower loitering speeds and low-bypass-ration powerplants for supersonic dashes.

"We have ways to modify the bypass ratio by clutching a fan stage in and out and changing the airflow around the engine," Burkholder said. "You can basically adapt the engine. If you want to fly fast and you need a lot of thrust, you turn it into a low bypass [system]. If you want to hang around and you don't want to burn a lot of fuel, then you turn it into a hi-bypass [configuration]."

LibertyWorks is also working on a Hi-Power/Low-Diameter engine that is embedded "in the heart" of an airframe to reduce its emissions and avoid detection by enemy sensors, but still provide high amounts of thrust and efficient fuel burn, Burkholder said.

In the past modifying engine inlets or exhausts to mask their radar signatures and emissions for increased survivability of the platform has carried with it a penalty in engine performance, he said.

"We aren't all the way there, but we have taken some big steps from the legacy systems," he said. Such propulsion could be applicable to the Air Force's future stealthy cargo aircraft, which is provisionally dubbed AMC-X, according to the company.

Burkholder and Jarvi said the LibertyWorks stresses factoring cost issues in the engine designs from day one.

"We can't continue the trend that every propulsion system cost more than the one before," said Jarvi, noting the desire to slash both the developmental and sustainment costs of future powerplants. Accordingly, LibertyWorks engineers are asked "not to just think about technical capability, but technical capability at an affordable price" considering issues such as ease of repair and maintaining simplicity of design.

"There is an old adage that says 80 percent of the cost gets designed in [to] the basic architecture," added Burkholder. Without due diligence, "you could very well be doing an architecture that traps costs in," he said.

Burkholder said another initiative of the LibertyWorks is to ensure Rolls-Royce engines can run on the alternative fuels currently under examination by the DoD.

The Air Force, for example, plans to conduct a flight demonstration in September of a B-52H Stratofortress bomber with two of the aircraft's eight engines burning a blend of conventional jet fuel and an alternate fuel derived from natural gas. This experiment is part of the Pentagon's Assured Fuel Initiative that seeks to reduce the military's reliance on foreign energy sources by converting coal, of which the United States has abundant reserves, into liquid fuel.

The Air Force says the fuel derived from refining natural gas under a Fischer-Tropsch process that is named after its German inventors of the 1920s, is virtually identical to the liquid fuel that coal would provide.

"We are also talking with the Air Force in what part we can play in advancing the fuels," said Burkholder. "We have the advantage that the core engine that is used in the V-22, the C-130s and the Global Hawks is very similar to the core engine we use in regional service. So you could start to build a synergy where if that core is cleared to run on both fuels, you could have a commercial and military application."

Should use Google instead! :-)

My goggles always fill up with water when I scuba dive.

I found your article quite interesting. Surprising amount of schematic detail. Here is a less-technical, but more broadly useful article...giving the "big picture" that should contribute something:

China makes spying a company policy
By Scott L. Wheeler, Insight News, Nov. 12, 2002

by purchasing high-tech firms in the United States, China gains access to advanced weapons technology which then is duplicated on Chinese production lines - World: Espionage

A U.S. high-tech firm bought in 1995 with Clinton-administration approval by a consortium that included two Chinese companies is proving to be a threat to U.S. national security, according to senior government analysts. The Anderson, Ind., based Magnequench Inc. was bought by the San Huan New Materials and Hi-Tech Co. of the People's Republic of China (PRC), which was started and still is partially owned by the Chinese Academy of Sciences in Beijing. It teamed in this venture with a Hong Kong investment house and a U.S. firm to form Magnequench International, which since has bought out at least one U.S. national laboratory spin-off company and has been project partner with another lab.
"The company is little more than a front for the PRC," a senior government analyst tells INSIGHT. The official insists that the PRC owners of Magnequench are using its status as a U.S. company to obtain "state-of-the-art and emerging technology and transfer it to the PRC.... It's just another form of espionage."
Magnequench itself is a General Motors (GM) spin-off company that produces rare-earth permanent magnets that have practical uses in electric motors. But these magnets also are used in advanced military equipment such as magnetic bearings in high-performance gas-turbine engines and in permanent-magnet submarine-propulsion systems, and are a key component in missile-guidance systems. The concerns expressed by the senior government analyst are that the technology and equipment used to produce the permanent magnets here in the United States would not be allowed for export to the PRC. But, because Magnequench supposedly is a U.S. company owned partly by a Chinese company, there is no control over how the technology is used. And the source indicates the technology is being used to enhance the PRC's production capabilities. "They have already duplicated the existing manufacturing line in China," the source tells INSIGHT.
The chairman of Magnequench is Hong Zhang, who also is chairman of San Huan. The company's president and chief executive officer, Archibald Cox Jr., tells INSIGHT that he did not believe his Chinese partners posed a threat. "There is no story about China stealing technology," he says. Cox points out that since a recent realignment of the corporate structure, "San Huan's stake is only 20 percent now." He also acknowledges, though, that there was no wall of security protecting U.S.-developed technology from Magnequench's Chinese partners.
The senior government official says that the activities of Magnequench since the 1995 buyout by the Chinese companies point to an aggressive pursuit of U.S. high-technology in rare-earth permanent magnets. In 1998 Magnequench acquired a small company formed by the Idaho National Engineering and Environmental Laboratory (INEEL), a U.S. national laboratory. This company, GA Powders, was put together by two scientists who had developed an atomization process to aid in the production of high-tech neodymium-iron-boron permanent magnets while they worked at INEEL.
The U.S. national labs have been identified by U.S. counterintelligence as targets of PRC espionage attempts--especially the Los Alamos National Laboratory where the government says the theft of the nuclear W-88 warhead design occurred through a series of espionage efforts by the PRC.
The senior government analyst who is monitoring Magnequench says that by acquiring GA Powders the company has gained new technology developed at one of the nation's most important labs. "The Idaho lab is where some of the most exotic work is done on new materials, including ordnance and other materials used in advanced manufacturing.... It is a tremendous security issue." Indeed, in an internal newsletter the Sandia National Laboratory also has reported working on a joint project with Magnequench involving rare-earth magnets. The newsletter quotes a Sandia scientist involved in the project as saying, "Enabling aspects include advanced electrical controls [and] new magnet technology." The senior government analyst calls the project "a disturbing partnership."
In March 2000, Magnequench International announced that it would open "Magnequench Tianjin Co. Ltd., a new neodymium-powder plant, in Tianjin, China. This plant opening will locate the production of neodymium-iron-boron permanent magnetic powder close to the source of raw materials." The senior government analyst says this fits a pattern for the PRC: "They seem to be cloning whatever they do at Magnequench USA in China."
When the consortium composed of two PRC companies and one U.S. company teamed up to buy Magnequench in 1995, the deal had to be approved by the Committee on Foreign Investment in the United States (CFIUS). Chaired by the secretary of the Treasury, CFIUS is an interagency committee responsible for conducting thorough reviews of foreign companies attempting to purchase stakes in U.S. companies. Once notified of a foreign interest in a U.S. company, CFIUS determines whether the foreign interest would pose a threat to national security. The 1988 Exon-Florio provision to the Defense Production Act gives the president the authority to restrict a foreign company from investing in a U.S. company if it poses a national-security risk.
Such occasions are rare, but they do occur. In 1990, President George H.W. Bush ordered the state-owned China National Aerospace Technology Import and Export Corp. (CATIC) to divest its interest in the Seattle-based MAMCO Manufacturing Inc. CFIUS allegedly had approved the deal and CATIC already had taken over MAMCO when the president stepped in and gave CATIC 90 days to divest. After six months CATIC still had not sold its interest in MAMCO, so the Treasury Department placed the company in the hands of American trustees and restricted CATIC's access to the company until it could be extricated from its financial stake in MAMCO.
CFIUS would not discuss the MAMCO case or any other reviews it conducts, but a source who at the time provided the president with an analysis of the firm tells INSIGHT that "even though MAMCO had no U.S. defense contracts" the machine tools in the MAMCO shop "could significantly increase the PRC's military capability." Five years after President George H.W. Bush ordered CATIC to divest its interest in MAMCO on the basis of a national-security threat, say well-placed sources, the Magnequench deal sailed right through the foreign investment review process with only a few dissenters from the defense establishment. President Bill Clinton showed no interest in exercising his authority to order the Chinese company to divest Magnequench under the Exon-Florio provision initiated by Democrats in Congress.
"Magnequench is a greater threat" than MAMCO, says the senior government analyst. "The danger is manifold--it gives the Chinese the ability to produce very reliable servos and actuators." Servos are small, powerful motors "critical to advanced weapons systems." Another U.S. official tells INSIGHT that the servos and actuators are used for "missiles, rockets and precision-guided bombs." The senior government analyst tells INsight that the Magnequench technology being transferred to China has a bifurcated risk: "It enables them to produce super-high-quality rare-earth magnets/ring magnets for use in gas centrifuges to produce nuclear-weapons material. And in addition to enhancing their own nuclear-weapons program we know that China has already proliferated ring magnets to Pakistan, which played a critical role in developing Pakistan's nuclear weapons."
In February 1996 the Washington Times reported that the CIA "has uncovered new evidence China has violated U.S. antiproliferation laws by exporting nuclear-weapons technology to Pakistan." It later was confirmed by Congress that military-industrial companies in China had sold 5,000 ring magnets to Pakistan.
Proponents of even more-liberalized trade with China often point to economic successes in joint projects which they say have pried open the bamboo curtain and promoted better relations with the PRC. Defense experts, on the other hand, point to China's nuclear-weapons program and related proliferation of weapons technology and say these relations may come at a higher cost to national security--and, in time, even of millions of lives.

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