“It’s a proprietary technology, but includes the application of several well established theoretical principles to propulsion and aerodynamic systems which should allow for efficient flight of non-standard aerodynamic platforms." So said Dr. John W. Fischer, NAVAIR’s new Director of Research and Engineering Sciences, in describing “vortex oscillating propulsion systems," a proprietary technology being developed by Russia’s Saratov Aviation. “It has the potential for commercial applications that include UAVs, a new class of aircraft for rough field operations, and long distance cargo transport."
In September, NAVAIR and Saratov signed an agreement to jointly pursue this new flying vehicle concept. Cooperation between the two countries could also transform traditional research and development methodologies.
Vortex oscillating propulsion reportedly yields efficient flight of odd-shaped objects. In traditional fixed-wing flight, the bigger bite the wing takes out of the air – called “the angle of attack” – the less smoothly the air flows over the wing. Beyond the point called the critical angle of attack, the airflow breaks up and the wing loses its lift. This limits the different flight attitudes, accelerated G-load limits, and the flight performance of any traditional airplane. Odd shapes on an airframe just make matters worse because of aerodynamic interference. The thrust vectoring, used by the F-22 and other newest generation fighters, is one way to help compensate for the limitations of airfoils. Vortex oscillation propulsion is another new technology that could expand the flight envelope of aircraft. The fall-out for aviation is that as lift is increased, the effect of weight, and therefore thrust required for a particular performance, is decreased, according to Fischer.
As a provider of advanced technologies for the DOD, NAVAIR found itself in a good position to embark upon a Russian partnership. However, research is always a risk, noted Fischer. It could blossom or go nowhere at all. But NAVAIR’s business is largely research.
After a trip to Russia recently, Fischer’s NAVAIR team and Saratov signed a letter of intent to jointly pursue the technology. Fischer sees not only potential military applications, but possible commercial applications as well. The flight test program will be conducted at NAS Patuxent River, MD, the Navy’s testing ground for new aircraft. Initially, a small UAV will be built and tested to validate new aircraft concepts and propulsion systems. If this succeeds, a larger variant could be pursued.
Saratov Aviation has been in the airplane business since before World War II. It produced the Yakolev (YAK)-38 vertol “jump jet” for the USSR. With the advent of the Confederation of Independent States and the Russian Federation, Saratov has moved into aerospace research and development.
“Vortex oscillation propulsion” is a sensitive, proprietary technology to Saratov Aviation. NAVAIR was given some very top-level descriptions “but not many details,” noted Fischer.
The Saratov plant is in Saratov, Russia, a city of 1 million people about 500 miles south of Moscow. Perhaps its biggest claim to fame was its air-training academy for Soviet cosmonauts. Yuri Gagarin’s* flight suit and training airplane remain on display.
NAVAIR became involved in this partnership through Rep. Curt Weldon (R-PA), vice-chairman of the House Armed Services Committee, and chairman of that committee’s tactical air and land forces panel. When the Russian Federation was formed, they investigated how to connect to US business for partnerships. Weldon – who has a background in rotary wing aviation -- learned of Saratov and what they were working on and approached NAVAIR to explore opportunities for joint development projects. Saratov wants to develop American markets and is interested long-term in development of some “very large” aircraft for the American market.
One issue not yet resolved involves dealing with Russian intellectual property. Russia’s laws on this are not as well defined as those in the US, and Saratov, understandably, wishes to retain the benefits of its ideas.
So far, Saratov has built a small mock-up of the shape that they believe might be of value to the Russian market, and has tested it aerodynamically and done basic systems integration to see if it would move forward. They have some wind tunnel test data that indicates that the concept is valid.
While NAVAIR has not yet built a test vehicle, it is putting together a program plan and determining how to approach such a joint program. A budget is in the works, with more detail due in the coming months. This is NAVAIR’s first development program with Russia, although not DOD’s first.
“Likely steps will be to develop a program plan; build a prototype; fly it; get test data; do an analysis; and show that it is real on that scale,” said Fischer. “This would lead to an acquisition program.” Concurrent with that, while prototypes are being tested, NAVAIR would also look at systems to which this technology could be applied specifically for the Navy and Marine Corps.
*Gagarin became the first man in space in 1961.
Yak-38s on flight deck at dea