为研究超临界二氧化碳(Supercritical Carbon Dioxide,SCO2)扇贝阻尼密封在不同工况下动力稳定性，建立SCO2扇贝阻尼密封数值计算模型，分析进口压力、温度及转速对SCO2扇贝阻尼密封动力特性及泄漏特性的影响。结果表明：直接复合刚度随涡动频率增加由正变负；交叉复合刚度随进口温度、压力增加而减小，随转速增加而增大；SCO2扇贝阻尼密封的有效阻尼随进口温度、转速增加而减小，随进口压力增加而增大，进口压力为8.1 MPa时有效阻尼约为7.7 MPa时的1.7~2.9倍；扇贝阻尼密封直接复合刚度、有效阻尼整体上大于迷宫密封，稳定性高于迷宫密封，但泄漏量略高于迷宫密封。

To explore the dynamic stability of supercritical carbon dioxide (SCO2) scallop damper seal under different operating conditions,a numerical calculation model of the scallop damper seal working with the SCO2 was established.The effects of various parameters such as inlet pressure,inlet temperature and rotational speeds on the rotordynamic characteristics and leakage performance of the scallop damper seal working with the SCO2 were analyzed.Results indicate that the direct complex stiffness changes from positive to negative with the increase of whirling frequency; the crosscoupled complex stiffness reduces with the increase of inlet temperature and pressure,while it rises with the increase of rotational speed;the effective damping of the scallop damper seal working with the SCO2 diminishes with the increase of inlet temperature and rotational speed,while it increases with the increase of inlet pressure.When the inlet pressure is 8.1 MPa,the effective damping is about 1.7 to 2.9 times of that under 7.7 MPa.The direct complex stiffness and effective damping of the scallop damper seal are significantly greater than those of the labyrinth seal.The scallop damper seal possesses better stability.Besides,the leakage flowrate of the scallop damper seal is slightly higher than that of the labyrinth seal.

TK263

国家自然科学基金项目(51875361)；上海市自然科学基金（20ZR1439200）