An inhomogeneous hydrogen-air mixture is induced once hydrogen leakage occurs, and an explosion may be triggered due to an accidental ignition with sufficient strength. The effects of different hydrogen concentration gradients on flame behavior and overpressure were experimentally investigated in a closed cubic vessel with a volume of 0.125${\text{m}}^3$. The transverse concentration gradients of hydrogen injected from the top face of the vessel were recorded using five oxygen sensors. A high-speed photography was employed to capture the flame shape evolution and the flame tip velocity was derived. Three piezoelectric pressure transducers were mounted on the top and side walls to measure the pressure-time profiles. The results show that the maximum overpressure in homogeneous mixtures is larger than that in inhomogeneous mixtures for fuel-lean hydrogen-air mixtures. However, the maximum overpressure in inhomogeneous mixtures is equal to or larger than that in homogeneous mixtures for fuel-rich hydrogen-air mixtures. Due to a larger difference between the upward and downward flame speeds, a mushroom-like shape flame was recorded in inhomogeneous hydrogen-air mixtures in fuel-lean to slightly fuel-rich hydrogen-air mixtures. The flame speed in two directions has the almost same value in inhomogeneous fuel-richer mixtures. The average flame speed in inhomogeneous mixtures is significantly larger than that in homogeneous mixtures for fuel-rich hydrogen air mixtures.

一旦发生氢气泄漏，就会引起不均匀的氢气-空气混合物，并且由于意外点火而可能触发爆炸，并具有足够的强度。在容积为0.125的密闭立方容器中，通过实验研究了不同氢浓度梯度对火焰行为和超压的影响。${\text{米}}^3$。使用五个氧气传感器记录了从容器顶面注入的氢气的横向浓度梯度。采用高速摄影来捕获火焰形状的演变，并得出火焰尖端速度。在顶壁和侧壁上安装了三个压电压力传感器，以测量压力时间曲线。结果表明，对于贫燃料的氢-空气混合物，均质混合物的最大超压大于非均质混合物的最大超压。然而，对于富含燃料的氢气-空气混合物，非均匀混合物中的最大超压等于或大于均匀混合物中的最大超压。由于向上和向下火焰速度之间的差异较大，在稀燃至稀有燃料的氢气-空气混合物中，在不均匀的氢气-空气混合物中记录到蘑菇状火焰。在不均匀的富燃料混合物中，两个方向的火焰速度几乎具有相同的值。对于富含燃料的氢气空气混合物，非均质混合物中的平均火焰速度明显大于均质混合物中的平均火焰速度。