Rotating detonation designs make progress on multiple continents
By Shikha Redhal and Eric Bach |December 2024
The Pressure Gain Combustion Technical Committee advances the investigation, development and application of pressure gain technologies for improving propulsion and power generation systems and achieving new mission capabilities.
Advancements this year led to an international expansion of pressure gain combustion research. This was evident at the 13th International Workshop on Detonation for Propulsion hosted by the University of Michigan in June, which was attended by nearly 100 researchers from around the world. In July, European Commission-funded research into the integration of rotating detonation engines began. Organized under the doctoral training network Harnessing Hydrogen’s Potential With Rotating Detonation, or H2POWRD, and coordinated by TU Berlin, the program comprises a consortium of 18 international partners.
In February, the Netherlands Organisation for Applied Scientific Research tested the first hydrogen-air RDE in the Netherlands. The parametric study measured the sensitivity of pressure gain and combustion efficiency to engine geometry, mixture ratio and total mass flow, which provided data for a quasi-1D thermodynamic RDE performance model. The Institute of Gas Turbine and Aerospace Propulsion at TU Darmstadt in Germany tested a small-scale RDE powered by gaseous hydrogen and oxygen in April, to identify the operating characteristics of RDEs with comparable total mass flows to satellite thrusters. The German Aerospace Center’s, or DLR’s, Institute of Space Propulsion conducted initial tests in May on an RDE with oxygen/hydrogen and oxygen/methane to determine the operating characteristics of RDEs for rocket propulsion, including gas generator applications.
At Poland’s Institute of Aviation, researchers continued to mature their liquid kerosene-air, hollow ramjet RDE with prolonged operation in a water-cooled configuration. In September, they conducted the first experiments with a calorimetric 3D-printed hydrogen -air RDE to gather data on heat loads and temperatures. The Romanian Research and Development Institute for Gas Turbines in July partnered with the von Karman Institute for Fluid Dynamics in Brussels and the Polytechnic University of Madrid to study pulsed and rotating detonation combustion.
In June, researchers at the University of Central Florida demonstrated Jet-A aerosolized 5-micrometer monodispersed liquid fuel cloud detonations, showing the dynamics and details of the droplet burning behavior. In March, NASA’s Marshall Space Flight Center in Alabama conducted ground tests of a 10,000-pound-force dual regenerative fully additively manufactured RDE, powered by liquid methane and liquid oxygen. The team achieved the highest average pressure, operating the RDE at 750 pounds per square inch absolute, and is now preparing for a ground demonstration of the world’s first turbomachinery integrated RDE lander for the moon or Mars.
The U.S. Naval Postgraduate School in California continued to analyze the design, operability and performance impact of fuel injection strategies for RDE designs. In May, researchers at Argonne National Laboratory in Illinois developed a one-of-its-kind high-order discontinuous Galerkin spectral element method framework within their Nek5000 flow solver to simulate detonative combustion.
In March, researchers at Purdue University of Indiana and Spectral Energies of Ohio demonstrated megahertz-rate heat-flux measurements in a hydrogen-air RDE via an atomic layer thermopile. They compared their results to numerical predictions of local transient heat fluxes previously conducted at North Carolina State University. In February, with NASA’s Glenn Research Center in Ohio, the Purdue and Spectral team investigated liquid injection in RDEs and captured the first million-frames-per-second volumetric fluorescence images of detonation-spray interactions. In May, they demonstrated phase Doppler interferometry for the first time within the RDE. The observed drop size distributions suggested substantial breakup and atomization of liquid jets.
At the University of Alabama in Huntsville, a small-scale RDE was tested in June with multiple fuel-oxidizer combinations to prove its operability, characterize performance and inform the design of efficient, compact chemical satellite thrusters. In November, researchers from Nagoya University, Muroran Institute of Technology, Keio University and the Japan Aerospace Exploration Agency launched a pressurized liquid ethanol-nitrous oxide RDRE aboard a sounding rocket. It produced 438 newtons of thrust and a specific impulse of 244 seconds
Contributors: Venkat Athmanathan, John W. Bennewitz and Jason Burr
