空气和水两种介质物理性质的巨大差异会对跨介质航行器的动力学环境产生复杂影响． 文中以雷诺数为参考，采用 CFX 软件设计案例进行仿真，研究航行器在跨越不同流体介质时的动力学特性． 仿真结果表明:跨越过程中流场存在一个雷诺数拐点，雷诺数小于拐点时，若水和空气的雷诺数相同，航行器的水、空流体动力学参数随攻角变化的趋势一致且数值相近;若水和空气的雷诺数相似，则存在一个匹配的飞行与潜航速度区间，仍能满足水、空介质间相似的动力学特性． 文中研究结论可为航行器的航行控制提供设计依据．

The huge physical-characteristic differences between air and water would produce complicated impact on
the dynamic environment of trans-media vehicles． In this paper，with the Reynolds number (Re) as reference，the dynamic property of the vehicles crossing different fluids are simulated by using the software CFX to design cases． Simulation results show that there exists a Re inflection point in the flow field during the crossing process，and that，when Re is less than the inflection point，if the Re of the air and the Re of the water are the same，the change trends of aerodynamic parameters and hydrodynamic ones with the attack angle are consistent and their numerical values are similar，and if the Re of the air is close to that of the water，there exists a matching range between flight speed and submerged speed，in which the aerodynamic characteristics are shown to be similar to the hydrodynamic ones． The conclusions can provide a basis for the design of voyage control．