节流孔截面形状对静压干气密封稳态性能和压力波动特性影响

建立了不同形状节流孔出口截面静压干气密封的几何模型，采用湍流大涡模拟方法数值求解了小孔节流静压干气密封的瞬态流场和压力场，对比了节流孔出口开设圆角、倒角与经典小孔节流静压干气密封的开启力、泄漏率等稳态性能参数和节流孔出口附近的压力波动特性，以较大密封开启力和较小压力波动为目标，获得了节流孔出口倒角和圆角的优选值范围. 结果表明:相较于经典小孔节流静压干气密封，节流孔出口开设倒角或圆角能提高静压干气密封的开启力，显著降低节流孔出口压力波动，且当倒角为0.3~0.4 mm，圆角为0.1~0.3 mm时具有最佳效果. 

Effect of Orifice Cross-Section Shape on Steady Performance and Pressure Fluctuation Characteristics of Hydrostatic Dry Gas Seal

Geometrical model of hydrostatic dry gas seal with different orifice cross-section shape was established. The transient flow field and pressure field of hydrostatic dry gas seals with orifice-type restrictor were solved numerically by large eddy simulation method. The steady-state performance, such as opening force and leakage rate, and pressure fluctuation characteristics adjacent to the outlet of orifice of hydrostatic dry gas seal with filleted or chamfered orifices and typical orifice-type restrictor were compared and analyzed. For the purpose of obtaining large opening force and small pressure fluctuation, the preferred values of chamfer and fillet were obtained. The results show that the fillet and chamfer on the outlet of orifice can enhance opening force and reduce pressure fluctuation of hydrostatic dry gas seal significantly compared to that with typical orifice-type restrictor. The preferred chamfer was from 0.3 to 0.4 mm, and the preferred fillet was from 0.1 to 0.3 mm.