The success of the launch mission depends on the dynamic characteristics of the rocket engine system, while the engine development process is based on the parameter sensitivity analysis. However, the dynamic characteristics and parameter sensitivity of the hydrogen-oxygen expansion cycle engine remain unclear. This research built the simulation model of basic components and overall system of the hydrogen-oxygen expansion cycle engine. A 3-factor and 9-level numerical simulation study was carried out based on the structural parameters of the cooling channel. Results show that at 0.1s after the ignition of the engine, the speed of oxygen pump drops by 16.4%, while the torque of the hydrogen turbine drops by 43.6%. The rise of coolant temperature between the inlet of the cooling channel and the outlet of combustion chamber is about 185 K, which is about 4 times of that between the outlet of combustion chamber and the first section outlet of the nozzle. The sensitivity of the response time to the rib height reaches 0.36, while the sensitivity of response time to the rib width and the nozzle wall thickness are 0.15 and 0.12, respectively. These findings contribute to the start-up analysis and design of the hydrogen-oxygen expansion cycle engine.

发射任务的成功取决于火箭发动机系统的动态特性，而发动机研制过程则基于参数敏感性分析。然而，氢氧膨胀循环发动机的动态特性和参数敏感性尚不清楚。本研究建立了氢氧膨胀循环发动机基本部件和整体系统的仿真模型。基于冷却通道的结构参数，进行了3​​因子9级数值模拟研究。结果表明，发动机点火后0.1s，氧泵转速下降16.4%，而氢涡轮扭矩下降43.6%。冷却通道入口与燃烧室出口之间的冷却液温度升高约185 K，大约是燃烧室出口与喷嘴第一段出口之间距离的4倍。响应时间对肋高度的灵敏度达到0.36，而响应时间对肋宽度和喷嘴壁厚的灵敏度分别为0.15和0.12。这些发现有助于氢氧膨胀循环发动机的启动分析和设计。