摘要
为获得高进口预旋条件下迷宫密封转子动力特性,阐明其气流激振失稳机制,本文基于西安交通大学动密封转子动力特性实验台,实验研究了高进口预旋条件下(预旋比μ_(0)>0.8),压比以及转速对迷宫密封转子动力特性影响规律。实验测量了2种压比(π=3.0,4.0)、3种转速(n=3000,6000,12000 r/min)下迷宫密封频率相关的转子动力特性系数。研究发现:高预旋条件下,迷宫密封交叉刚度始终为较大的正值,导致有效阻尼始终为负值,不利于转子系统稳定,容易诱发转子失稳;压比对迷宫密封转子动力特性影响显著,随压比增加,迷宫密封直接刚度幅值显著增大,交叉刚度始终为正值且幅值显著增大,有效阻尼明显降低;转速对迷宫密封转子动力特性影响较小,直接刚度、直接阻尼对转速变化不敏感,基本保持不变,交叉刚度随转速增加略微增加,进而导致有效阻尼略微减小。
To better understand the rotordynamic characteristics of a labyrinth seal at high inlet preswirl and elucidate the mechanism of instability induced by airflow,the rotordynamic characteristic test rig of Xi’an Jiaotong University was utilized to research the effects of pressure ratio and rotational speed on the rotordynamic characteristics of the labyrinth seal at high inlet preswirl(preswirl ratio μ_(0)>0.8).The frequency-dependent rotordynamic coefficients were measured at two pressure ratios(π=3.0,4.0)and three rotational speeds(n=3000,6000,12000 r/min).The results show that at high inlet preswirl,the labyrinth seal had always a large positive cross-coupled stiffness so that its effective damping was always negative,which was not conducive to the stability and may cause instability of the rotor system.It is also shown that the rotordynamic characteristics were significantly affected by the pressure ratio:As the ratio increased,the direct stiffness increased greatly,the cross-coupled stiffness was always positive and increased greatly,and the effective damping decreased significantly and that the rotordynamic characteristics were slightly affected by the rotational speed:Direct stiffness and direct damping were insensitive to speed change and remained substantially unchanged,and the cross-coupled stiffness increased slightly along with the speed increase,resulting in a slight decrease of effective damping.
作者
方志
李志刚
王天昊
薛文松
李军
FANG Zhi;LI Zhigang;WANG Tianhao;XUE Wensong;LI Jun(School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2022年第7期86-95,共10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
迷宫密封
转子动力特性
高进口预旋
压比
转速
labyrinth seal
rotordynamic characteristics
high inlet preswirl
pressure ratio
rotational speed
