Time-resolved Measurements of Detonation Decoupling and Amplification

Chin, Hardeo M.; Cuppoletti, Daniel R.; Ombrello, Timothy; Rein, Keith D.; Ahmed, Kareem A.

doi:10.2514/6.2020-1175

Cited by 3 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is very likely that the rapid energy release and subsequent expansion of the products behind the transverse detonation act as a piston to overdrive the Mach stem through the re-initiation process. This mechanism also acts to explain the overdriven speed measurements and pressure amplification recently observed in experiments of Chin et al [56] for detonation quenching and re-initiation following a critical geometric area expansion.…”

Section: Triple Point Speeds and The Transverse Detonation Strengthsmentioning

confidence: 58%

On the role of transverse detonation waves in the re-establishment of attenuated detonations in methane-oxygen

Floring¹,

Peswani²,

Maxwell³

2022

Preprint

View full text Add to dashboard Cite

This investigation concerns the problem of detonation attenuation in stoichiometric methane-oxygen and its re-establishment following its interaction with obstacles, using high resolution numerical simulation. The main focus was on the role of the transverse detonation on the re-establishment of the detonation wave, and the importance of applying a numerical combustion model that responds appropriately to the thermodynamic state behind the complex shock wave dynamics. We applied an efficient thermochemically derived four-step global combustion model using an Euler simulation framework to investigate the critical regimes present. While past attempts at using one-or two-step models have failed to capture transverse detonations, for this scenario, our simulations have demonstrated that the four-step combustion model is able to capture this feature. We thus suggest that to correctly model detonation reinitiation in characteristically unstable mixtures, an applied combustion model should contain at least an adequate description to permit the correct ignition and state variable response when changes in temperature and pressure occur, i.e. behind shocks. Our simulations reveal that (1) there is a relationship between the critical outcomes possible and the mixture cell size, and (2) while pockets of unburned gas may exist when a detonation re-initiates, it is not the direct rapid consumption of these pockets that gives rise to transverse detonations. Instead, the transverse detonations are initiated through

show abstract

Section: Triple Point Speeds and The Transverse Detonation Strengthsmentioning

confidence: 58%

On the role of transverse detonation waves in the re-establishment of attenuated detonations in methane-oxygen

Floring¹,

Peswani²,

Maxwell³

2022

Preprint

View full text Add to dashboard Cite

show abstract

Detonation wave diffraction in stoichiometric C2H4/O2 mixtures using a global four-step combustion model

Peswani

Maxwell

2022

Physics of Fluids

View full text Add to dashboard Cite

In this study, we revisit the problem of detonation diffraction in mildly irregular ethylene-oxygen mixtures using high resolution numerical simulations. In particular, we focus on the re-initiation of diffracted waves in the critical regime and the role of transverse detonations on the re-establishment of the detonation. This problem is significant for characterizing detonation wave propagation as well as for the development of next-generation detonation engines. A thermochemically derived four-step combustion model that responds appropriately to the thermodynamic state behind the complex shock wave dynamics was adopted in an Euler framework. While past attempts using simplified combustion models have largely failed to predict the onset of transverse detonations near the critical limit, our simulations demonstrate that the four-step model can capture these features. Our results reveal that transverse triple point collisions are fundamental for triggering the re-initiation of the detonation and that multiple modes of re-initiation exist in the critical regime. The transverse detonation initiation distance and wall reflection lengths are then compared with experimental measurements and found to be in agreement. We also demonstrate that the incident wave re-establishes at the Chapman-Jouguet speed when re-initiation occurs through the diffraction process. However, if re-initiation of a quenched detonation occurs by a transverse detonation following the reflection of the expanding wave at the boundary, the re-initiated detonation becomes overdriven along the Mach wave. Finally, it was found that the transverse detonations are Chapman-Jouguet detonations that travel in the shocked but unreacted gas.

show abstract

Impact of a Magnetic Field on a Propagating Detonation Wave in an Unconfined Tube

Coffey

Anand

Gaetano

et al. 2020

AIAA Propulsion and Energy 2020 Forum

View full text Add to dashboard Cite

Time-resolved Measurements of Detonation Decoupling and Amplification

Cited by 3 publications

References 3 publications

On the role of transverse detonation waves in the re-establishment of attenuated detonations in methane-oxygen

On the role of transverse detonation waves in the re-establishment of attenuated detonations in methane-oxygen

Detonation wave diffraction in stoichiometric C2H4/O2 mixtures using a global four-step combustion model

Impact of a Magnetic Field on a Propagating Detonation Wave in an Unconfined Tube

Contact Info

Product

Resources

About