Detonation front structure and the competition for radicals

Liang, Zhe; Browne, S.; Deiterding, Ralf; Shepherd, Joseph E.

doi:10.1016/j.proci.2006.07.244

Cited by 61 publications

(32 citation statements)

References 29 publications

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“…It has been proposed that the product, (E/R)(t i /t e ), provides a figure of merit for stability [61,62]. The smaller values of the product are associated with the more stable detonations; the larger values with unstable detonations.…”

Section: Detonation Wavesmentioning

confidence: 99%

Autoignitions and detonations in engines and ducts

Bradley

2012

Phil. Trans. R. Soc. A.

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The origins of autoignition at hot spots are analysed and the pressure pulses that arise from them are related to knock in gasoline engines and to developing detonations in ducts. In controlled autoignition engines, autoignition is benign with little knock. There are several modes of autoignition and the existence of an operational peninsula, within which detonations can develop at a hot spot, helps to explain the performance of various engines. Earlier studies by Urtiew and Oppenheim of the development of autoignitions and detonations ahead of a deflagration in ducts are interpreted further, using a simple one-dimensional theory of the generation of shock waves ahead of a turbulent flame. The theory is able to indicate entry into the domain of autoignition in an 'explosion in the explosion'. Importantly, it shows the influence of the turbulent burning velocity, and particularly its maximum attainable value, upon autoignition. This value is governed by localized flame extinctions for both turbulent and laminar flames. The theory cannot show any details of the transition to a detonation, but regimes of eventually stable or unstable detonations can be identified on the operational peninsula. Both regimes exhibit transverse waves, triple points and a cellular structure. In the case of unstable detonations, transverse waves are essential to the continuing propagation. For hazard assessment, more needs to be known about the survival, or otherwise, of detonations that emerge from a duct into the same mixture at atmospheric pressure.

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Section: Detonation Wavesmentioning

confidence: 99%

Autoignitions and detonations in engines and ducts

Bradley

2012

Phil. Trans. R. Soc. A.

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“…By transforming the detonation data into a moving reference frame with horizontal and vertical velocity components matching the main detonation front speed, U M , and transverse wave speed, U T , respectively, and by subsequently rotating the moving reference frame through an angle that matches the shock intersection track angle, tan ϕ = U T /U M , the local equivalence of the two flow fields becomes apparent (see figure 4). The most visually striking similarity is the duplication of the double, mutually inverted, λ-point structures in the CFD results of Liang et al [17] for weakly unstable detonation in comparison with the type IV interaction data. Noting the suppressed reaction rate for the jet fluid in the type IV interaction discussed previously, it is reasonable to propose that the previously unexplained "fracture" (that appears as a nearly horizontal dark feature in this reference frame) in the corner of the OH PLIF keystone reaction zone suggests the presence of a cold jet in the detonation case also.…”

Section: Structural Equivalencementioning

confidence: 56%

Reactant Jetting in Unstable Detonation

Sanderson

Austin

Liang

et al. 2009

39th AIAA Fluid Dynamics Conference

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“…These numerical simulations solved inviscid two-dimensional and three-dimensional Euler equations both with a simplified reaction model (Liang et al, 2007) and a detailed reaction model (Westbrook, 1982), and applied a classical second-order accurate MUSCL-TVD (Monotone Upstream-centered Schemes for Conservation Laws -Total Variation Diminishing) scheme.…”

Section: (Adaptive Mesh Refinementmentioning

confidence: 99%

“…Based on these ideas above, we conducted a series of numerical simulations on detonation initiation and propagation using a hot jet in supersonic combustible mixtures (Cai et al, 2015a;Liang et al, 2014;Cai et al, 2014;Cai et al, 2015b;Cai et al, 2016a;Cai et al, 2016b) with the open-source program AMROC (Deiterding, 2003;Liang et al, 2007;Deiterding, 2009;Deiterding, 2011;Ziegler et al, 2011) …”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Detonation Control Using a Pulse Hot Jet in Supersonic Combustible Mixture

Cai

Liang

Deiterding

2016

Combustion Science and Technology

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Abstract:To investigate the mechanism of detonation control using a pulse hot jet in the supersonic hydrogen-oxygen mixture, high-resolution simulations with a detailed reaction model were conducted using an adaptive mesh refinement method. After the successful detonation initiation, a contractive passway was generated between the hot jet and the main flow field behind the detonation front. Due to the contractive passway, the expansion of detonation products was prevented, hence resulting in overdriven detonation. By setting up various contractive passways through adjusting the width of the hot jet, the overdrive degree of overdriven detonation also changes. It is suggested that the width of the hot jet has approximately linear relation with the relative and absolute propagation velocities. When the contractive passway gradually disappeared after the shutdown of the hot jet, overdriven detonation attenuated to the dynamically stable Chapman-Jouguet (CJ) detonation. When the contractive passway was re-established once again after the re-injection of the hot jet, the CJ detonation developed to the same overdriven detonation, indicating that the contractive passway controlled by the pulse hot jet can indeed control detonation propagation in the A c c e p t e d M a n u s c r i p t 2 supersonic combustible mixture to some extent.

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Detonation front structure and the competition for radicals

Cited by 61 publications

References 29 publications

Autoignitions and detonations in engines and ducts

Autoignitions and detonations in engines and ducts

Reactant Jetting in Unstable Detonation

Numerical Investigation on Detonation Control Using a Pulse Hot Jet in Supersonic Combustible Mixture

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