Effects of the equivalence ratio on turbulent flame–shock interactions in a confined space

Wei, Haiqiao; Zhao, Jianfu; Zhou, Lei; Gao, Dawei; Xu, Zailong

doi:10.1016/j.combustflame.2017.08.009

Cited by 37 publications

(22 citation statements)

References 66 publications

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“…The development of the flame when it passed through the obstacle was demonstrated in with a relatively larger pressure to a large space with relatively smaller pressure will decrease, which is likely the mechanism of Venturi effect. Consequently, the gas flow velocity decreased after the perforated plate according to previous work [41], which contributes to the flame front velocity decrease. Fig.…”

Section: The Process Of Flame Accelerationsupporting

confidence: 55%

“…The experiments apparatus is same with our previous study [41], thus the detailed information is not shown here due to the limited length of paper. The experimental apparatus was composed of the constant volume combustion vessel, the orifice plate, the intake and exhaust pipe system, the ignition system, the heating system, time synchronizing system, image acquisition system, and in-cylinder pressure acquisition system.…”

Section: Methodsmentioning

confidence: 99%

“…The flame front velocity is an intrinsic property of a premixed flame, which was widely used in the previous study of the flame acceleration and transition to detonation. And a brief review on the flame front velocity could be obtained in our previous study [41]. Based on a framing rate of 160,000 frames per second and a resolution of 0.18 mm/pixel, the uncertainty is 28 m/s.…”

Section: Experimental Conditionsmentioning

confidence: 99%

“…A velocity point is calculated from the difference in the centerline flame position between consecutive frames. In our previous work [41], a detailed investigation regarding the definition of flame front velocity was reviewed.…”

Section: Definition Of Flame Front Velocitymentioning

confidence: 99%

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Turbulent flame propagation with pressure oscillation in the end gas region of confined combustion chamber equipped with different perforated plates

Zhou

Gao

Zhao

et al. 2018

Combustion and Flame

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Experiments were conducted in a newly designed constant volume combustion chamber with a perforated plate by varying the initial conditions. Hydrogen-air mixtures were used and the turbulent flame, shock wave, and the processes of flame-shock interactions were tracked via high-speed Schlieren photography. The effects of hole size and porosities on flame and shock wave propagation, intensity of the shock wave and pressure oscillation in closed combustion chamber were analyzed in detail. The effect of interactions between the turbulent flame and reflected shock or acoustic wave on the turbulent flame propagation was comprehensively studied during the present experiment. The results demonstrated that flame front propagation velocity and pressure oscillation strongly depend on the hole size and porosities of the perforated plate. The flame front propagation velocity in the end gas region increases as hole size increases and porosity decreases. The flame front propagation intensity in the end region of a confined space is strongly relevant to two competing effects: the initial turbulent formation and turbulent flame development. The experimental results indicated that an oscillating flame is associated with both the reflected shock wave and the acoustic wave. Meanwhile, different turbulent flame propagations and combustion modes were observed.

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Section: The Process Of Flame Accelerationsupporting

confidence: 55%

Section: Methodsmentioning

confidence: 99%

Section: Experimental Conditionsmentioning

confidence: 99%

Section: Definition Of Flame Front Velocitymentioning

confidence: 99%

See 2 more Smart Citations

Turbulent flame propagation with pressure oscillation in the end gas region of confined combustion chamber equipped with different perforated plates

Zhou

Gao

Zhao

et al. 2018

Combustion and Flame

Self Cite

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“…8,9 However, the quantitative theory and comprehensive mechanism of DDT remain still poorly understood as a result of its complicated combination of multiple highly nonlinear processes including interactions among flames, shocks, boundary layers, and turbulence. 2 In particular, detonation development in confined space has become a new forefront topic recently on account of its close relation to superknock occurring in downsized spark ignition engine, [10][11][12][13][14][15] in which the complex flame-pressure wave interactions play a crucial role in the end-gas autoignition formation and its inducing detonation. [12][13][14] When superknock occurs, the peak pressure in the cylinder can reach up to over 300 bars that can damage the engine, which has become an obstacle for the development of an advanced engine.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of end-gas autoignition induced by flame-pressure interactions in confined space

Deiterding

2019

Physics of Fluids

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Flame propagation behavior of propane–air premixed combustion in a confined space with two perforated plates at different initial pressures

Zhang

Wang

et al. 2022

Energy Science & Engineering

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The aim of this paper is to analyze local autoignition induced by secondary flame acceleration. The secondary flame acceleration process and the local autoignition formation mechanism at the condition of the secondary flame acceleration propagation were investigated by utilizing an improved designed constant volume combustion bomb (CVCB) with two perforated plates. Primary flame and secondary flame propagation were recorded via high‐speed schlieren photography. The results showed that there were three distinct stages in the process of flame propagation through two perforated plates, which were the primary jet flame stage, secondary jet flame stage, and flame‐shock interaction stage. The morphologies of the flame were analyzed by high‐speed Schlieren images, flame velocities, and pressure oscillation including primary jet propagation, secondary flame formation and acceleration, and location autoignition. Results show the effect of initial pressure on flame propagation, flame velocity, and pressure oscillation. Acceleration of secondary flame and local autoignition phenomenon was more precisely demonstrated as unburnt gases were compressed by flame waves (different velocities) with initial pressure increasing. Based on the morphology of flame, three different types of flame combustion modes were captured at different initial pressure involving turbulent flame, deflagration, and quasi‐detonation. The present work might provide a new insight for combustion science in a confined space, such as autoignition due to compression effect of secondary jet flame and primary flame interaction. It also provides the theory guidance and research direction towards further studies on propane storage vessel deflagration.

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Effects of the equivalence ratio on turbulent flame–shock interactions in a confined space

Cited by 37 publications

References 66 publications

Turbulent flame propagation with pressure oscillation in the end gas region of confined combustion chamber equipped with different perforated plates

Turbulent flame propagation with pressure oscillation in the end gas region of confined combustion chamber equipped with different perforated plates

Mechanism of end-gas autoignition induced by flame-pressure interactions in confined space

Flame propagation behavior of propane–air premixed combustion in a confined space with two perforated plates at different initial pressures

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