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从激光点火的热机理出发，通过对一维有限差分模型的模拟和计算，分析了时间步长（△ｔ）和空间步长（△ｘ）对点火能量阈值及点火延迟时间的影响。结果表明，点火能量阈值在一定范围内只与△ｘ有关，而与△ｔ无关。△ｘ一定时，点火延迟时间随着△ｔ的增大而缓慢增加。当入射激光能量接近点火能量阈值时，点火延迟时间基本上不随△ｔ变化而变化，但△ｘ＞２．５ × １０－５ｍ时，点火延迟时间受△ｔ影响较大。△ｔ一定，当入射激光能量远大于点火能量阈值时，点火延迟时间随着△ｘ的增大呈三次方曲线增加。
Based on the thermal mechanism of laser ignition, the influence of time step (Δt) and space step (Δx) on the ignition energy threshold and ignition delay time are analyzed through the simulation and calculation of one-dimensional finite difference model. The results show that the ignition energy threshold within a certain range only with △ x, and has nothing to do with △ t. △ x constant, the ignition delay time increases slowly with △ t. When the incident laser energy is close to the ignition energy threshold, the ignition delay time basically does not change with Δt, but when Δx> 2.5 × 10-5m, the ignition delay time is greatly affected by Δt. △ t is certain, when the incident laser energy is far greater than the ignition energy threshold, the ignition delay time increases with the increase of △ x cubic curve increased.