中文摘要：

为研究障碍物截面变化对混合气体爆炸特性参数的影响规律,运用3D动态流体动力学软件AutoRea Gas建立障碍物截面不同变化方式和趋势的爆炸模型,模拟分析截面不同变化方式（渐变、突变）和不同变化趋势（由大变小、由小变大）对气体爆炸特性参数（速度、压力场）的影响程度和规律。研究表明：改变障碍物的截面变化方式和趋势都会影响可燃气体的爆炸参数。对于爆炸压力场,截面变化情况下的爆炸超压大于截面不变的情况,截面渐变大于截面突变的情况,截面由大到小变化与截面由小到大变化下的爆炸超压呈现相反变化趋势。对于爆炸速度场,截面不同变化方式和趋势下的速度变化情况均为在开始的一小段时间内先减小然后逐渐增大。

英文摘要：

In order to study the influence rules on characteristic parameters of mixed gas explosion by section variation of obstacle, the 3D dynamic fluid dynamics software AutoReaGas was used to establish the explosion model with different variation patterns and trends of obstacle section, and the influence extent and rules on characteristic parameters of gas explosion （velocity, pressure field） by different variation patterns （gradual change, sudden change） and different variation trends （from large to small, from small to large） of section were simulated and analyzed. It showed that both changing the variation pat- terns and trends of obstacle section will influence the explosion parameters of combustible gas. For explosion pressure field, the explosion overpressure with section variation is larger than that without variation, and the explosion overpressure with gradual changing section is larger than that with sudden changing section, while the explosion overpressure with section variation from large to small presents the opposite variation trend with that from small to large. For explosion velocity field, the velocity change conditions under different variation patterns and trends of section all decrease in a short period after explosion, and then increase gradually.