Numerical analysis of a vented methane/air explosion in a large-scale chamber

The internal and external flow fields during vented explosions of methane were characterized through numerical simulation, and the capability of numerical simulation thereof was validated by previous experimental data at three ignition positions. The venting mechanism was revealed by the simulated concentration distribution, temperature profile, and airflow velocity. The results show rear ignition results in the external methane mass distribution taking the form of "mushroom" and columnar flames in the external space, which can be expressed as a third-order polynomial relationship with distance; central ignition forms a relationship of the form y = Ax^B. Front ignition causes the temperature to show a tendency to repeated oscillations (rising, falling, and rising). Central ignition generates the maximum vented airflow velocity (V_max = 320 m/s) upon vent opening. The results indicate that it is acceptable to apply numerical simulation of methane explosions in practice.