Purdue University, AFRL Regional Network – Midwest collaborate on solid rocket fuel project

WRIGHT-PATTERSON AIR FORCE BASE, Ohio (AFRL) — Researchers at Purdue University, with support from the Air Force Research Laboratory, or AFRL, have filed a patent disclosure to develop solid fuels for rotating detonation engines. The project was awarded in collaboration with the AFRL Regional Network – Midwest, headquartered at Purdue. The Midwest Network is a new science and technology ecosystem that brings together academia, industry and government agencies to advance research and technology critical to the Air Force mission.

“AFRL actually provided much of the impetus for this particular project,” said Terrence Meyer, professor of mechanical engineering at Purdue University. “[AFRL] sought this out as a potential alternative to liquid or gaseous rotating detonation engine fuels and has been critical in the initial ideas as well as continuing to provide insights and direction.”

The Purdue University project is developing solid propellants for rotating detonation rocket engines, an advanced type of propulsion technology that utilizes continuous detonation waves to combust fuel, according to Meyer. The technology offers a potentially more efficient and powerful means of propulsion with smaller engines than typical constant pressure combustion engines.

“The idea to use solid propellants for rotating detonation is a fairly new one,” said Eric Paulson, senior aerospace engineer at AFRL. “The innovative work that has been done at Purdue and a couple other places in the U.S. is really cutting-edge technology. There’s a lot of work that has been done with liquids, but rotating detonation with solid fuel is a pretty new game.”

According to Paulson, this proof of concept is key to gaining additional funds for a more substantive effort at maturing this high interest technology so it could potentially be used in rotating detonation engines across the DOD.

“Most combustion devices operate in subsonic combustion,” said Meyer. “Detonative combustion operates in a supersonic mode. So, it burns faster and burns at a higher pressure at a constant volume.”

Other advantages with solid fuels are that, unlike liquid or gas-based fuels, they do not need complicated tubing or plumbing, which allows for smaller engines and saving space in the vehicle’s design. Solid propellants can likewise address safety concerns when handling fuel.

“Solid fuels are not as temperamental as liquid or gaseous fuels,” said Steven Son, Alfred J. McAllister professor of mechanical engineering at Purdue. “You can make a solid propellant, put it on a shelf, and wait five years, and it will still go right up without hesitation.”

The increased stability of solid fuel can not only make handling safer, but the increased shelf life could also help alleviate potential supply chain issues for in-theater warfighters.

“[Solid fuels] do not leak,” said Meyer. “If you get a hole of some kind in a liquid fuel tank, then you are going to have liquid fuel that could cause a safety issue. With a solid, you are not going to have that safety issue.”

The AFRL Regional Network emerged from the Air Force Science and Technology 2030 strategy One of the strategies to expand science and technology collaboration was the creation of regional networks. Purdue University was awarded the Midwest regional network, and Cornell University was awarded the Mid-Atlantic regional network.

The AFRL Regional Network – Midwest is partnered with 44 academic institutions and over 170 businesses with 35 active projects across the Midwest region and continuing to grow.

“If you’re doing research and it touches national security, then you should be working with one of our DOD labs,” said Dr. Stacy M. Manni, director of the AFRL Regional Network – Midwest. “But working with a DOD lab is not always easy. You don’t necessarily know how to make contacts, or your contacts may move or retire. We’re able to make connections in just about any area that exists.”

The Regional Networks aim to leverage research, translation and workforce development nationwide, to encourage science and technology exchanges and drive meaningful innovation. It also seeks to develop relationships between AFRL researchers and partners to address defense-related matters and establish partnerships that will provide access to valuable resources as well as seedling funding for projects, according to Manni.

“Ultimately, these connections will provide significant benefits to AFRL, the Department of the Air Force, and the Department of Defense,” said Manni. “AFRL benefits by gaining access to new technologies and ideas through these collaborative endeavors. This type of direct interaction will further accelerate and advance the translation of science and technology to both the warfighter and commercial markets.”

For information on joining the AFRL Regional Network – Midwest, visit https://midwesthub.afresearchlab.com/join/

For more examples on ongoing research projects, visit the AFRL Regional Network – Midwest YouTube channel.

About AFRL

The Air Force Research Laboratory is the primary scientific research and development center for the Department of the Air Force. AFRL plays an integral role in leading the discovery, development, and integration of affordable warfighting technologies for our air, space and cyberspace force. With a workforce of more than 12,500 across nine technology areas and 40 other operations across the globe, AFRL provides a diverse portfolio of science and technology ranging from fundamental to advanced research and technology development. For more information, visit: www.afresearchlab.com.