ADELPHI, Md. — Years of Army scientific research culminated in the successful flight demonstration of a 3D-printed heavy-fuel rotary-engine series-hybrid system, advancing power and propulsion science for future tactical unmanned aircraft systems.
Researchers at the U.S. Army Combat Capabilities Development Command, known as DEVCOM, Army Research Laboratory, designed the advanced drone propulsion through its Versatile Tactical Power and Propulsion essential research program.
“The program addresses critical power and propulsion challenges by advancing fundamental science that could enable drones to fly longer and faster, operate at higher altitudes, carry heavier payloads and perform in extreme environments while reducing logistics burdens,” said Dr. Chol-Bum “Mike” Kweon, DEVCOM ARL program manager. “For warfighters, the program has transitioned research findings to industry partners for maturation and integration into capabilities that could enable mid-sized drones to operate beyond line of sight, extending the reach of ground commanders and reducing risk to Soldiers.”
ARL researchers used advanced computational fluid dynamics modeling and a clean-sheet design approach to address the challenges of efficiently burning heavy fuel in a rotary engine. The work improved fuel atomization and vaporization while minimizing compressed-air and fuel-vapor leaks.
“The use of advanced manufacturing, including 3D metal printing, allowed us to rapidly redesign engine components based on lessons learned through experimentation,” Kweon said. “It enabled us to design an air-cooled engine that reduces propulsion-system size and eliminates the need for liquid coolant.”
Integrated with a novel 400-volt motor-generator system, the engine forms a heavy-fuel rotary-engine series-hybrid system designed to support vertical takeoff and landing operations in contested environments.
To demonstrate the propulsion system in flight, ARL worked with industry partners, including Griffon Aerospace, to develop an aircraft platform around the propulsion system. The novel series hybrid system powers the Group 3 midsized, unmanned aircraft system, Versatile Intelligence Controlled Tactical Operational Reconnaissance and Attack, or VICTOR UAS.
The Versatile Intelligence-Controlled Tactical Operational Reconnaissance and Attack, or VICTOR unmanned aircraft system, developed by DEVCOM ARL and industry partners demonstrating launch, flight and landing capabilities near Huntsville, Alabama. (U.S. Army video Casey Knighten)
The VICTOR essential research program generated many additional outcomes for the Army, industry and academia, including:
Collaborative research with more than 30 universities, more than 13 federal laboratories and more than 20 industry partners that resulted in hundreds of scientific journal publications in diverse areas including combustion chemistry, sensing and controls, material design, batteries and hybrid electric technology
Professionally developed hundreds of scientists and engineers now working in government, industry and academia
Research advances that address energy and propulsion challenges relevant to tactical-level energy independence
Technical data packages, design methods and reliability lessons applicable to future propulsion and drone design and integration efforts
Tens of patents and patent applications
Lessons from the essential research program will inform follow-on ARL research and industry development efforts, including the Persistent Unmanned Aircraft System for Logistics, Strike, Autonomy, and Reconnaissance, or PULSAR, an advanced drone-operation concept that enables multi-mission capabilities through a swarm of VICTOR drones.
The VICTOR UAS and the PULSAR concept will be made available to military partners for further experimentation and development. Industry partners will continue refining VICTOR UAS for other applications.
US Army DEVCOM Army Research Laboratory Public Affairs Office
