Impacts of rectangular obstacle lengths on premixed methane-air flame propagation in a closed tube

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.