Numerical simulation of flame acceleration and DDT(deflagration to detonation transition) in hydrogen-air mixtures with concentration gradients

ABSTRACT

In this paper, a coupled new solver is used to simulate the acceleration and deflagration to detonation transition (DDT) of inhomogeneous mixtures flame under obstacle conditions. Analyzed the variations of flame front, pressure and density with time. The experimental results show that the vertical concentration gradient affects the chemical reaction rate in the combustion reaction zone, resulting in the flame front stretching along the “front up-back down.” At the same time, the flame propagation velocity is affected by obstacles. After multi-stage “acceleration-deceleration,” it reaches 2700 m/s at 1.23 m from the ignition center, and the pressure jumps to 5.0 MPa. Finally, the transition from detonation to detonation is completed. It is worth noting that the local explosion point is in the corner of the obstacle or pipe wall. This simulation method is compatible with low Mach number laminar flow, turbulent flow, and compressible reaction flow problems under high Mach number. It provides prospective prediction for flame acceleration and detonation formation during hydrogen combustion and detonation engine operation.

KEYWORDS:

• OpenFOAM
• H₂
• concentration gradient
• flame acceleration
• deflagration to detonation transition

Acknowledgments

This work is supported by the Science and Technology Project of the State Grid Corporation of China (8000-201918445A-0-0-00).

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

This work was supported by the Science and Technology Project of the State Grid Corporation of China [8000-201918445A-0-0-00].

Notes on contributors

Yang Liu

Yang Liu is a student of China University of Mining and Technology (Beijing) the author is mainly engaged in experimental diagnosis and numerical simulation of combustible gas explosion and combustible liquid fire.

Xing Yang

Xing Yang is a student of China University of Mining and Technology (Beijing).

Zhixi Fu

Zhixi Fu is a student of China University of Mining and Technology (Beijing).

Peng Chen

Peng Chen is a teacher of China University of Mining and Technology (Beijing), the author is mainly engaged in experimental diagnosis and numerical simulation of combustible gas explosion.