A 2D CFD model investigation of the impact of obstacles and turbulence model on methane flame propagation

Nguyen, Tien Thua; Strebinger, Claire; Bogin, Gregory E.; Brune, Jürgen F.

doi:10.1016/j.psep.2020.08.023

Cited by 45 publications

(4 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meanwhile, they also found the vessel overpressure could be influenced by the combustion of the residual unburnt mixture in the vessel after burn‐up. Nguyen et al 23 studied the influence of obstacle shape, turbulence model, and spark position on flame propagation and turbulence. This research prompted them further to analyze the interaction between flame and fluid dynamics.…”

Section: Introductionmentioning

confidence: 99%

“…Meanwhile, they also found the vessel overpressure could be influenced by the combustion of the residual unburnt mixture in the vessel after burn-up. Nguyen et al 23 At present, extensive researches have been conducted on the complete flush of premixed gas into connected pipelines, but the characteristics of those explosions, which occur in partial methane areas and propagate to non-methane areas, are rarely reported. In this study, the characteristics of such CH 4 explosions were evaluated through a self-built horizontal pipeline test system.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Study on characteristics of methane explosion flame and pressure wave propagation to the non‐methane area in a connected chamber

Liu

Wang

et al. 2021

Fire and Materials

View full text Add to dashboard Cite

This study is aimed at investigating the characteristics of CH 4 explosion diffusion and propagation to the non-methane area. The CH 4 explosion pressure and flame were tested with the aid of a self-built horizontal pipeline system. On this basis, the flame images, photoelectric signals, and pressure propagation laws during explosions of methane with different volume fractions in the pipeline were obtained. The experimental research results indicate that an obvious secondary explosion pressure occurs at L/D = 3.5. After the explosion pressures at different positions along the entire pipeline reach the peak values, they experience varying degrees of oscillations. The maximum explosion pressure in the non-methane zone may occur at different length-to-diameter ratios. When the volume fraction of CH 4 is larger, the maximum explosion pressure occurs farther. However, the explosion pressure at the end of the pipeline is lower than that at the explosion source. The flame intensity and flame duration of methane explosion are remarkably enhanced at L/D = 17.5 and then become gradually weakened in the non-methane area. The variations of explosion pressure are always prior to those of flame signal. CO and CO 2 are the main toxic and harmful gases produced by methane explosions, and high-concentration (13% in this experiment) methane explosions produce a small amount of hydrocarbon gases such as C 2 H 4 and C 2 H 6 . The volume fractions of the gases produced decrease with the increase in the distance from the explosion source. The research results boast great significance for suppressing methane explosions and their propagation in the pipeline.

show abstract

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Study on characteristics of methane explosion flame and pressure wave propagation to the non‐methane area in a connected chamber

Liu

Wang

et al. 2021

Fire and Materials

View full text Add to dashboard Cite

show abstract

“…For complex coupled pressure-velocity calculations, the PISO algorithm is used to couple pressure-velocity, as it can improve the convergence speed compared to the SIMPLE algorithm. Convergence is achieved by ensuring all residuals are dropped at least three magnitudes at every time step [39]. The residuals are less than 1 × 10 −6 for the energy equation and less than 1 × 10 −5 for other equations.…”

Section: Initial Condition and Solvermentioning

confidence: 99%

Effect of Obstacle Gradient on the Deflagration Characteristics of Hydrogen/Air Premixed Flame in a Closed Chamber

Wang,

Zhong

2024

Processes

View full text Add to dashboard Cite

In this paper, computational fluid dynamics (CFD) numerical simulation is employed to analyze and discuss the effect of obstacle gradient on the flame propagation characteristics of premixed hydrogen/air in a closed chamber. With a constant overall volume of obstacles, the obstacle blocking rate gradient is set at +0.125, 0, and −0.125, respectively. The study focuses on the evolution of the flame structure, propagation speed, the dynamic process of overpressure, and the coupled flame–flow field. The results demonstrate that the flame front consistently maintains a jet flame as the obstacle gradient increases, with the wrinkles on the flame front becoming increasingly pronounced. When the blocking rate gradients are +0.125, 0, and −0.125, the corresponding maximum flame propagation speeds are measured at 412 m/s, 344 m/s, and 372 m/s, respectively, indicating that the obstacle gradient indeed increases the flame propagation speed. Moreover, the distribution of pressure is closely related to changes in the flame structure, with the overpressure decreasing in the obstacle channel as the obstacle gradient increases. Furthermore, the velocity vector and vortex distribution in the flow field are revealed and compared. It is found that the obstacle tail vortex is the main factor inducing flame evolution and flow field changes in a closed chamber. The effect of the blocking rate gradient on flow velocity is also quantified, with instances of deceleration occurring when the blocking rate gradient is −0.125.

show abstract

“…These obstacles, with different geometries, positions [5,6], blocking probability [7,8] and numbers of obstacles [9], all have different effects on the combustion and explosion of premixed gas. The research on this problem was mostly carried out through experiments [10,11] or simulations [12,13]. Patel et al [14] built a platform of closed pipe with three flat obstacles and found the pressure of premixed methane-air drastically increased.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Premixed Methane–Air Explosion in a Closed Tube with U-Type Obstacles

et al. 2022

View full text Add to dashboard Cite

Given the spatial structures and functional requirements, there are a number of different types of obstacles in long and narrow confined spaces that will cause a premixed gas explosion to produce greater overpressure and influence the flame behavior for different obstacles. Because the volume fraction of unburned gas changes with the changing height of the U-type obstacles, we can further study the influence on the volume fraction of the unburned premixed gas for the characteristics of the overpressure and the flame behaviors in the closed tube with the obstacles. The results show that after the premixed gas is successfully ignited in the pipe, the overpressure in the pipe greatly increases as the unburned premixed gas burns between the adjacent plates. Moreover, the increase of the overpressure in the closed duct becomes faster when the decrease of unburned gas becomes faster. The high-pressure areas between the plates move inversely compared with the direction of flame propagation when the height of the U-type increases, whereas the high pressure in the front of the flame moves further when the flame propagation passes all obstacles. In addition, the reversed flow structure of the flame is a coupling result for the overpressure caused by the flame propagation and the vortex between the plates. From the perspective of production safety, this study is a significant basic subject about the characteristics of overpressure and flame behaviors in a closed tube with obstacles.

show abstract

A 2D CFD model investigation of the impact of obstacles and turbulence model on methane flame propagation

Cited by 45 publications

References 32 publications

Study on characteristics of methane explosion flame and pressure wave propagation to the non‐methane area in a connected chamber

Study on characteristics of methane explosion flame and pressure wave propagation to the non‐methane area in a connected chamber

Effect of Obstacle Gradient on the Deflagration Characteristics of Hydrogen/Air Premixed Flame in a Closed Chamber

Numerical Simulation of Premixed Methane–Air Explosion in a Closed Tube with U-Type Obstacles

Contact Info

Product

Resources

About