Revisiting unsteady shock-induced combustion with modern analysis techniques

Pavalavanni, Pradeep Kumar; Sohn, Chae Hoon; Lee, Bok Jik; Choi, Jeong‐Yeol

doi:10.1016/j.proci.2018.07.094

Cited by 11 publications

(11 citation statements)

References 13 publications

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“…By increasing the y ‐direction spatial resolution with a block size of 32 × 8 cells, the calculated frequency increases to 410 kHz. Other studies 43,44 also suggest an improved numerical accuracy of the oscillation frequency by increasing the grid resolution. Back to Figure 10 (top), it is also interesting to observe that 1) a small strip of isolated combustion area forms in front of the main detonation wave at t = 57.79

μ

s, 2) it then develops upwards and merges with the main combustion area at t = 58.75

μ

s and 3) the merged reacting front continues to move along the circular direction at t = 59.71

μ

s.…”

Section: Numerical Results and Discussionmentioning

confidence: 96%

“…The surrounding reactive gas mixture is featured by the molar ratio of H 2 :O 2 :N 2 being 2:1:3.76, static pressure of p ∞ = 320 mmHg and static temperature of T ∞ = 293 K. The projectile velocity is u ∞ = 2605 m/s, corresponding to a supersonic flight Mach number of M = 6.46. subdetonation case 40 . The surrounding reactive gas mixture is featured by the molar ratio of H 2 :O 2 :N 2 being 2:1:0, static pressure of p ∞ = 186 mmHg and static temperature of T ∞ = 293 K. The projectile velocity is u ∞ = 1892 m/s, corresponding to M = 3.55. trans‐detonation case 41‐44 . The surrounding reactive gas mixture is the same as that of the superdetonation case.…”

Section: Numerical Results and Discussionmentioning

confidence: 99%

“…trans‐detonation case 41‐44 . The surrounding reactive gas mixture is the same as that of the superdetonation case.…”

Section: Numerical Results and Discussionmentioning

confidence: 99%

“…The transdetonation case involves an interesting phenomenon of the oscillating reacting front. As shown in Figure 10 (top), the instantaneous temperature fields exhibit obvious unsteady combustion with a noncircular reacting front, which belongs to the regular regime 44 in that the flow oscillates with high frequency and low amplitude. Of all the Lehr's experiments, the Mach 4.48 case gives a measured frequency of 425 kHz.…”

Section: Numerical Results and Discussionmentioning

confidence: 99%

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The variable‐extended immersed boundary method for compressible gaseous reactive flows past solid bodies

Wang

Zhang

2021

Numerical Meth Engineering

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An immersed boundary method (IBM) has been developed to handle the solid body embedded flowfield simulation for compressible reactive flows, paving the way of application for a wide range of fluid–solid interaction problems. Previously, the Brinkman penalization method (BPM), originated from porous media flows, has been successfully used for incompressible Navier–Stokes equations by adding penalization terms to momentum equations. However, it is nontrivial to solve the compressible form due to the penalized continuity equation that usually poses severe numerical stiffness. In order to circumvent this issue, an extending procedure for relevant variables from the fluid to solid domain is considered, by analyzing the ordinary differential equations remained after operator splitting. Density can be then determined with the help of an equation of state (EoS). Meanwhile, efforts of enforcing the Neumann boundary condition, for example, the adiabatic wall condition, on the fluid–solid interface can be minimized by extending temperature across the interface directly. One more advantage of the extending step lies in that it can quickly reach a steady state when performed within a narrow band around the interface. Implemented into an adaptive Cartesian grid‐based flow solver for compressible Navier–Stokes equations with chemical reaction source terms, the present variable‐extended IBM is validated by numerical examples ranging from single‐species nonreactive to multispecies detonative flows in one‐ and two‐dimensional domains. Numerical results show (1) the successful specification of slip or nonslip, adiabatic or isothermal wall condition on the fluid–solid interface and (2) loss of total energy in the original BPM being avoided and the numerical accuracy being improved especially for energy‐sensitive reactive flows.

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μ

s, 2) it then develops upwards and merges with the main combustion area at t = 58.75

μ

s and 3) the merged reacting front continues to move along the circular direction at t = 59.71

μ

s.…”

Section: Numerical Results and Discussionmentioning

confidence: 96%

Section: Numerical Results and Discussionmentioning

confidence: 99%

“…trans‐detonation case 41‐44 . The surrounding reactive gas mixture is the same as that of the superdetonation case.…”

Section: Numerical Results and Discussionmentioning

confidence: 99%

Section: Numerical Results and Discussionmentioning

confidence: 99%

See 2 more Smart Citations

The variable‐extended immersed boundary method for compressible gaseous reactive flows past solid bodies

Wang

Zhang

2021

Numerical Meth Engineering

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“…The influence of the size of the computational grid and the kinetics of chemical reactions on ignition due to the incidence of a shock wave on a poorly streamlined body was studied in detail in Ref. [11]. A stage was found numerically at which the reaction zone noticeably approaches the surface of the body, which leads to additional heat release from high-temperature reactions.…”

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confidence: 99%

Influence of Particle on Gas Detonation by Shock

2019

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There exist evidence, that the gaseous detonation passing through a cloud of solid particles could be attenuated or even suppressed. Contrary to these known works, in the present article, we have found that just one single 160-micron particle can serve as a trigger for the detonation onset. By numerical simulation, we have obtained that there are the concentration ratio limits, in which single particle is enough to initiate gaseous detonation, although without particle the detonation is not ignited in the same conditions in a tube of restricted size. In other words, the presence of a solid particle in the combustible mixture could decrease significantly the ignition delay time. Using of temperature pattern visualization, we have demonstrated that the ignition arises in the subsonic region located between the particle and the bow shock front. The approximations of the used model are discussed. It is shown that used assumptions are valid within investigated time intervals. The work performed with use of the supercomputer resources Interdepartmental Supercomputer Center Russian Academy of Sciences (ISC RAS)

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