Editing Pulse detonation engine (section)

{{short description|Rocket engine that uses detonation waves to combust fuel and oxidizer}}

A '''pulse detonation engine''' ('''PDE''') is a type of [[Air propulsion|propulsion]] system that uses [[detonation wave]]s to [[Combustion|combust]] the fuel and [[oxidizer]] mixture.<ref>{{cite journal |last1=Kailasanath |first1=K. |title=Review of Propulsion Applications of Detonation Waves |journal=[[AIAA Journal]] |date=September 2000 |volume=38 |issue=9 |pages=1698–1708 |doi=10.2514/2.1156 |bibcode=2000AIAAJ..38.1698K |url=https://arc.aiaa.org/doi/abs/10.2514/2.1156?journalCode=aiaaj |access-date=28 November 2021|url-access=subscription }}</ref><ref>{{cite journal |last1=Roy |first1=G.D. |last2=Frolov |first2=S.M. |last3=Borisov |first3=A.A. |last4=Netzer |first4=D.W. |title=Pulse detonation propulsion: challenges, current status, and future perspective |journal=Progress in Energy and Combustion Science |date=January 2004 |volume=30 |issue=6 |pages=545–672 |doi=10.1016/j.pecs.2004.05.001 |bibcode=2004PECS...30..545R |url=https://www.sciencedirect.com/science/article/abs/pii/S0360128504000383 |access-date=28 November 2021|url-access=subscription }}</ref>

The engine is pulsed because the mixture must be renewed in the [[combustion chamber]] between each detonation wave and the next.  Theoretically, a PDE can operate from [[subsonic flight|subsonic]] up to a [[hypersonic]] flight speed of roughly [[Mach number|Mach]] 5. An ideal PDE design can have a thermodynamic [[Fuel efficiency|efficiency]] higher than other designs like [[turbojet]]s and [[turbofan]]s because a detonation wave rapidly compresses the mixture and adds heat at constant volume. Consequently, [[moving parts]] like [[Axial compressor|compressor spools]] are not necessarily required in the engine, which could significantly reduce overall weight and cost. Key issues for further development include fast and efficient mixing of the fuel and oxidizer, the prevention of [[Autoignition temperature|autoignition]], and integration with an inlet and nozzle.

{{As of|May 2023}}, no practical PDE has been put into production, but several testbed engines have been built and one was successfully integrated into a low-speed demonstration aircraft that flew in sustained PDE powered flight in 2008.