Performance of a Rotating Detonation Rocket Engine with Various Convergent Nozzles and Chamber Lengths

John W. Bennewitz, Blaine R. Bigler, Mathias C. Ross, Stephen A. Danczyk, William A. Hargus and Richard D. Smith
Additional contact information
John W. Bennewitz: Air Force Research Laboratory, Edwards, CA 93524, USA
Blaine R. Bigler: Jacobs Technology Group, Air Force Research Laboratory, Edwards, CA 93524, USA
Mathias C. Ross: Department of Mechanical and Aerospace Engineering, UCLA, Los Angeles, CA 90095, USA
Stephen A. Danczyk: Air Force Research Laboratory, Edwards, CA 93524, USA
William A. Hargus: Air Force Research Laboratory, Edwards, CA 93524, USA
Richard D. Smith: GHKN Engineering LLC., Kirkland, WA 98034, USA

Energies, 2021, vol. 14, issue 8, 1-30

Abstract: A rotating detonation rocket engine (RDRE) with various convergent nozzles and chamber lengths is investigated. Three hundred hot-fire tests are performed using methane and oxygen ranging from equivalence ratio equaling 0.5–2.5 and total propellant flow up to 0.680 kg/s. For the full-length (76.2 mm) chamber study, three nozzles at contraction ratios ϵ c = 1.23, 1.62 and 2.40 are tested. Detonation is exhibited for each geometry at equivalent conditions, with only fuel-rich operability slightly increased for the ϵ c = 1.62 and 2.40 nozzles. Despite this, counter-propagation, i.e., opposing wave sets, becomes prevalent with increasing constriction. This is accompanied by higher number of waves, lower wave speed U wv and higher unsteadiness. Therefore, the most constricted nozzle always has the lowest U wv . In contrast, engine performance increases with constriction, where thrust and specific impulse linearly increase with ϵ c for equivalent conditions, with a 27% maximum increase. Additionally, two half-length (38.1 mm) chambers are studied including a straight chamber and ϵ c = 2.40 nozzle; these shortened geometries show equal performance to their longer equivalent. Furthermore, the existence of counter-propagation is minimized. Accompanying high-fidelity simulations and injection recovery analyses describe underlying injection physics driving chamber wave dynamics, suggesting the physical throat/injector interaction influences counter-propagation.

Keywords: rotating detonation rocket engine; detonation; counter-propagation; wave dynamics; injection recovery (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/8/2037/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/8/2037/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:8:p:2037-:d:531486

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().