The seal aerodynamic characteristics of supercritical carbon dioxide (SCO₂) are significant. The whirl model of two-control equation was established by splitting the original one-control equation to adapt to the mesh deformation of SCO₂ seal. The NIST REFPROP SCO₂ (real gas properties) was used as the working fluid to simulate the seal dynamic characteristics of SCO₂ turbine accurately. The effects of different fluids, rotational speeds, pressure ratios and whirl types on seal dynamic characteristics were compared and analyzed. The results show that the UDF of two-control equation can improve the simulation accuracy of seal. The pressure ratio, rotational speed and conical whirl motion all affect seal dynamics, in which the conical whirl motion is significant and makes seal dynamic stability poor.

超临界二氧化碳（SCO ₂）的密封空气动力学特性是显着的。为适应SCO ₂密封件的网格变形，对原一控制方程进行分裂，建立二控制方程的涡动模型。使用 NIST REFPROP SCO ₂（真实气体特性）作为工作流体来模拟 SCO ₂的密封动态特性涡轮准确。对比分析了不同流体、转速、压力比和涡流类型对密封动态特性的影响。结果表明，二控制方程的UDF可以提高密封的模拟精度。压力比、转速和锥形涡动运动都会影响密封动力学，其中锥形涡动运动显着，使密封动态稳定性较差。