对气氢亚燃冲压发动机突扩燃烧室进行了数值模拟研究。研究发现、喷嘴节距Ｓ／Ｄ和喷嘴离台阶的距离是设计试验件所需的重要参数，它们影响氢射流的穿透深度、氢浓度分布的均匀性和回流区内的氢浓度。氢射流和空气进口条件的改变也对氢气穿透深度有重要影响。 A numerical simulation study on the sudden expansion combustion chamber of a gas-hydrogen sub-combustion engine was carried out. The study found that the nozzle pitch S / D and nozzle distance from the step are important parameters for the design of the test piece. They influence the penetration depth of the hydrogen jet, the uniformity of the hydrogen concentration distribution, and the hydrogen concentration in the recirculation zone. Changes in the hydrogen jet and air inlet conditions also have a significant effect on the hydrogen penetration depth.