Scientists at the U.S. Department of Energy’s Argonne National Laboratory, along with Air Force Research Laboratory and Convergent Science Inc., have created a numerical modeling tool that allows for a better understanding of a powerful engine that could one day propel the next generation of airplanes and rockets.

Rotating detonation engines (RDEs) have received growing attention from the propulsion community in the last decade.

This three-dimensional numerical simulation captures complex combustion dynamics in a realistic, non-premixed, rotating detonation engine configuration. Source: Argonne National LaboratoryUnlike conventional gas turbine engines, which rely on subsonic constant pressure combustion, RDEs leverage high-intensity, self-sustaining detonation — described as a supersonic reaction wave coupled with a shock — to rapidly consume the fuel-air mixture, typically in a ring-shaped, cylindrical chamber.

The intense and rapid energy release from detonation can be used to generate extremely high thrust from a relatively small combustor.

In addition, the engines are compact, contain no moving parts, are more efficient than conventional combustion systems, provide steady thrust at high frequencies and can be integrated with existing aircraft and rocket engine hardware.

Argonne said that these features have made RDEs the subject of research by various agencies, including the Air Force, Naval and Army Research Laboratories, NASA and aerospace companies in the United States and abroad. But practical implementation of RDEs has been elusive.

“The operation and performance of RDEs depends on many factors,” said Brent Rankin, research engineer at Air Force Research Laboratory. ​“The combustion behavior must be studied and optimized over a large design space for the technology to become practically viable.”

Previous numerical simulations gave researchers insights into the combustion phenomena occurring in RDEs. However, they were computationally very expensive, precluding rigorous studies over a wide range of operating conditions.

In an effort to solve this problem, Sibendu Som, computational scientist and manager of Argonne’s Multi-Physics Computations group, and Pinaki Pal, mechanical engineer in Argonne’s Energy Systems division, teamed up with Rankin and researchers at Convergent Science Inc. to develop a computational fluid dynamics (CFD) model to predict the combustion behavior of RDEs.

The new model allows researchers to capture combustion behavior in realistic configurations accurately and at a reasonable cost. The model was validated against data provided by Rankin’s earlier experiments. The team demonstrated that the CFD model can capture RDE combustion dynamics under varying operating conditions.