Impacts of Rectangular Obstacle Lengths on Premixed Methane–Air Flame Propagation in a Closed Tube

Abstract To investigate the mechanism of the flame–vortex interaction induced by an obstacle, a numerical research of premixed methane–air flame dynamics in an obstructed chamber is described. Numerical simulations are performed with the OpenFOAM open-source CFD code. The simulation images show that the flame propagation process can be divided into four typical stages. A series of instabilities are captured in the simulation during flame propagation. More importantly, the numerical results demonstrate that a longer obstacle allows a sufficient accelerating time, which can give rise to a higher explosion overpressure and faster flame tip speed.