摘要
为降低透平机械中动静间隙泄漏量,提高机组运行效率与转子系统稳定性,以孔型密封为基本模型,提出了一种球凹孔腔、两种周向倾斜孔腔(倾斜角为±30°)和两种轴向倾斜孔腔(倾斜角为±20°)的密封结构。采用基于三维定常RANS方程的数值计算方法,研究了异形孔腔对液体孔型密封泄漏特性和转子耗功的影响,计算分析了不同转速(0~6000 r/min)下,典型孔型密封和5种异形孔密封结构的泄漏量、孔腔流场、湍动能耗散率分布和转子面拖拽力矩。结果表明:球凹孔腔在转速0~4000 r/min的范围内能显著降低密封泄漏量;周向倾斜孔腔能显著降低间隙内周向旋流,倾斜角为30°的周向斜孔密封具有更低的泄漏量;轴向倾斜孔腔能略微降低转子耗功,倾斜角为20°的轴向倾斜孔腔能降低泄漏量,而倾斜角为-20°的轴向倾斜孔腔导致泄漏量增加。
To reduce the leakage and increase the aerodynamic efficiency and rotor stability of turbomachinery,five hole seals with odd-shaped geometrical structures including a ball-shaped concave cavity,two circumferentially oblique hole geometries and two axially oblique hole geometries were presented based on the typical hole-pattern seal model.A steady numerical approach was used to investigate the influence of odd-shaped hole geometry on the leakage performance and rotor drag torque of hole-pattern seals.The leakage flow rate,cavity flow field,turbulent kinetic energy dissipation rate and the rotor drag torque were calculated and analyzed for the six hole seals(one typical hole seal and five odd-shaped hole seals)with different hole geometries at various rotational speeds(0,2000,4000,6000 r/min).Results showed that compared with the typical hole-pattern seal,the ball-shaped concave cavity can markedly reduce the leakage flow rate at the rotational speed range from 0 to 4000 r/min;circumferentially oblique holes can obviously decrease the circumferential swirl velocity in the seal gap.The circumferentially oblique hole with an oblique angleα=30°has the minimum leakage flow rate,and the axially oblique hole results in a slight decrease in the rotor drag torque.The axially oblique hole with an oblique angleβ=20°can reduce the leakage flow rate.Contrarily,the axially oblique hole with an oblique angleβ=-20°results in an increase in leakage flow rate.
作者
方志
李志刚
李军
FANG Zhi;LI Zhigang;LI Jun(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Collaborative Innovation Center of Advanced Aero-Engine,Beijing 100191,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2020年第1期143-149,共7页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51776152)
关键词
孔型密封
异形孔
泄漏特性
转子耗功
hole-pattern seal
odd-shaped hole geometry
leakage performance
rotor power loss
