開放空間中での火炎の加速と爆ごうへの遷移の実験

抄録

An experimental technique is developed to investigate the deflagration to detonation transition of gaseous mixtures in an unconfined space. Diluted stoichiometric ethane-oxygen mixtures are supported in atmosphere bounded by soap bubbles. Turbulences made by grids placed repeatedly in combustible gas mixtures intensify the burning, which causes acceleration of the flame and pressure waves. Transitions to detonations are observed in an unconfined space. If the shock waves are strong enough to make self-ignition, then a detonations occurs. A plane wall placed parallel to the direction of the flame propagation helps to make the condition of self-ignition. Critical conditions for transition to detonation depend on the heat release rate, intensity of turbulence, and boundary, which are related to each other.