Abstract
This paper describes numerical analysis on vented hydrogen-air deflagration. The numerical analysis target is 27 m^3 cubic chamber which has 2.6 m^2 vent area on the sidewall. Two different conditions of the hydrogen concentration are assumed, that is, uniform, and gradient. In the gradient case, the initial total mass of hydrogen in the chamber is the same as the uniform case. Also, three different ignition points are assumed, that is, rear, center, and front of the chamber from the vent. Only one peak was observed in rear ignition case, while some peaks appeared in the other ignition cases. The farther from the vent the ignition point became, the higher the peak pressure got. In the gradient case, the highest peak was lower than in the uniform case, though the initial total mass of hydrogen in the chamber was the same as the uniform case. This is because the amount of burned gas was smaller.
