Rotating detonation engine
A rotating detonation engine (RDE) is a proposed engine using a form of pressure gain combustion, where one or more detonations continuously travel around an annular channel. Computational simulations and experimental results have shown that the RDE has potential in transport and other applications.[1][2]
In detonative combustion, the results expand at supersonic speed. It is theoretically more efficient than conventional deflagrative combustion by as much as 25%.[3] Such an efficiency gain would provide major fuel savings.[4][5]
Disadvantages include instability and noise.
Concept
The basic concept of an RDE is a detonation wave that travels around a circular channel (annulus). Fuel and oxidizer are injected into the channel, normally through small holes or slits. A detonation is initiated in the fuel/oxidizer mixture by some form of igniter. After the engine is started, the detonations are self-sustaining. One detonation ignites the fuel/oxidizer mixture, which releases the energy necessary to sustain the detonation. The combustion products expand out of the channel and are pushed out of the channel by the incoming fuel and oxidizer.[2]
Although the RDE's design is similar to the pulse detonation engine (PDE), the RDE is superior because the waves cycle around the chamber, while the PDE requires the chambers to be purged after each pulse.[6]
Development
Several US organisations work on RDEs.
US Navy
The US Navy is pushing development.[7] Researchers at the Naval Research Laboratory (NRL) particular interest in detonation engines such as the RDE, capability to reduce the fuel consumption in their heavy vehicles.[8][9] Several obstacles still remain to overcome in order to use the RDE in the field.[10] NRL researchers are currently focusing on better understanding how the RDE works.
Aerojet Rocketdyne
Since 2010, Aerojet Rocketdyne has conducted over 520 tests of multiple configurations.[11]
NASA
Daniel Paxson[12] at the Glenn Research Center used simulations in computational fluid dynamics (CFD) to assess the RDE's detonation frame of reference and compares performance with the PDE.[13] He found that an RDE can perform at least on the same level as a PDE. Furthermore, he found that RDE performance can be directly compared to the PDE as their performance was essentially the same.
Energomash
According to Russian Vice Prime Minister Dmitry Rogozin,[14] in mid-January 2018 NPO Energomash company completed the initial test phase of a 2-ton class liquid propellant RDE and plans to develop larger models for use in space launch vehicles.
University of Central Florida
In May 2020, a team of engineering researchers affiliated with the US Air Force claimed to have developed a highly experimental working model rotating detonation engine capable of producing 200lbf (approximately 890N) of thrust operating on a hydrogen/oxygen fuel mix.[15]
Other research
Other experiments have used numerical procedures to better understand the flow-field of the RDE.[16] In 2020 a study from University of Washington explored an experimental device that allowed control of parameters such as the size of the cylinder gap. Using a high-speed camera they were able to view it operating in extreme slow motion. Based on that they developed a mathematical model to describe the process.[17]
See also
References
- Lu, Frank; Braun, Eric (7 July 2014). "Rotating Detonation Wave Propulsion: Experimental Challenges, Modeling, and Engine Concepts". Journal of Propulsion and Power. The American Institute of Aeronautics and Astronautics. 30 (5): 1125–1142. doi:10.2514/1.B34802. S2CID 73520772.
- Wolanski, Piotr (2013). "Detonative Propulsion". Proceedings of the Combustion Institute. 34 (1): 125–158. doi:10.1016/j.proci.2012.10.005.
- "В России испытали модель детонационного двигателя для ракет будущего". Российская газета. 2018-01-18. Retrieved 2018-02-10.
- Cao, Huan; Wilson, Donald (2013). "Parametric Cycle Analysis of Continuous Rotating Detonation Ejector-Augmented Rocket Engine". 49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference. doi:10.2514/6.2013-3971. ISBN 978-1-62410-222-6.
- Schwer, Douglas; Kailasanath, Kailas (25 September 2010). "Numerical Investigation of the Physics of Rotating Detonation Engines". Proceedings of the Combustion Institute. Elsevier, Inc. 33 (2): 2195–2202. doi:10.1016/j.proci.2010.07.050.
- "Pressure Gain Combustion Program Committee - Resources". AIAA Pressure Gain Combustion Program Committee. Retrieved 2016-12-30.
- "How the Rotating Detonation Engine Works". HowStuffWorks. 2013-03-08. Retrieved 2015-11-09.
- "US Navy developing rotating detonation engine". Physics Today. 2012-11-06. doi:10.1063/PT.5.026505. ISSN 0031-9228.
- "How the Rotating Detonation Engine Works". HowStuffWorks. 2013-03-08. Retrieved 2015-10-21.
- "Navy Researchers Look to Rotating Detonation Engines to Power the Future - U.S. Naval Research Laboratory". www.nrl.navy.mil. Retrieved 2015-11-09.
- Claflin, Scott. "Recent Advances in Power Cycles Using Rotating Detonation Engines with Subcritical and Supercritical CO2" (PDF). Southwest Research Institute. Retrieved 20 March 2017.
- "Daniel E. Paxson - Controls and Dynamics Branch Personnel". www.grc.nasa.gov. Retrieved 2020-02-20.
- "UCSB Full Bib - External Link". pegasus.library.ucsb.edu. Retrieved 2015-11-09.
- Facebook post, in Russian
- Blain, Loz. "World-first "impossible" rotating detonation engine fires up". New Atlas. New Atlas. Retrieved 6 May 2020.
- Schwer, Douglas; Kailasanath, Kailas (2011-01-01). "Numerical investigation of the physics of rotating-detonation-engines". Proceedings of the Combustion Institute. 33 (2): 2195–2202. doi:10.1016/j.proci.2010.07.050.
- Strickler, Jordan (February 19, 2020). "New detonating engine could make space travel faster and cheaper". ZME Science. Retrieved 2020-02-20.