袋型阻尼密封动力特性分析及对转子稳定性的影响
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摘要
密封动力特性对透平机械转子系统稳定性影响较大。文中应用非定常动网格技术建立了考虑转子涡动的袋型阻尼密封动力特性求解模型,在验证求解模型准确性的基础上,比较分析了转子涡动频率、涡动振幅对传统迷宫密封和袋型阻尼密封动力特性的影响,基于密封气动功方法定量分析了袋型阻尼密封的抑振机理。研究结果表明:与传统迷宫密封相比,袋型阻尼密封的周向隔板降低了密封腔内气流的周向速度,其泄漏特性与传统迷宫密封相当;在所研究的工况下,袋型阻尼密封指向转子涡动中心的径向气流力以及与转子涡动速度方向相反的切向气流力均大于传统迷宫密封,有效地降低了转子涡动振幅和涡动速度;与传统迷宫密封相比,转子涡动频率和涡动振幅越大,袋型阻尼密封气动功的绝对值越大,抑振效果越好。
The rotordynamic coefficients of seals are important parameters to evaluate the stability of rotor system in turbomachinery. A rotordynamic characteristics solution model of pocket damper seals considering whirl motion of the rotor using unsteady solution combined with mesh deformation technique was established. On the basis of verifying the accuracy of the solution model, comparative analysis of the whirl frequency and whirl amplitudes of the rotor influence on the rotordynamic characteristics of traditional labyrinth seals and pocket damper seals, and study the suppression vibration mechanism of pocket damper seals based on aerodynamic work. Study results show that: compared with traditional labyrinth seals, pocket damper seals reduce circumferential airflow velocity in seal cavity, and the leakage characteristic of pocket damper seals with almost equal to that of traditional labyrinth seals. In the present operating conditions range, pocket damper seals have a large radial airflow force pointing to the rotor whirl orbit center and a large tangential airflow force opposite to the rotor whirl velocity, so pocket damper seals effectively reduce rotor whirl amplitudes and whirl velocity. The larger whirl frequency and whirl amplitudes of the rotor, the greater the absolute value of aerodynamic work, and good suppression vibration effect of pocket damper seals.
The rotordynamic coefficients of seals are important parameters to evaluate the stability of rotor system in turbomachinery. A rotordynamic characteristics solution model of pocket damper seals considering whirl motion of the rotor using unsteady solution combined with mesh deformation technique was established. On the basis of verifying the accuracy of the solution model, comparative analysis of the whirl frequency and whirl amplitudes of the rotor influence on the rotordynamic characteristics of traditional labyrinth seals and pocket damper seals, and study the suppression vibration mechanism of pocket damper seals based on aerodynamic work. Study results show that: compared with traditional labyrinth seals, pocket damper seals reduce circumferential airflow velocity in seal cavity, and the leakage characteristic of pocket damper seals with almost equal to that of traditional labyrinth seals. In the present operating conditions range, pocket damper seals have a large radial airflow force pointing to the rotor whirl orbit center and a large tangential airflow force opposite to the rotor whirl velocity, so pocket damper seals effectively reduce rotor whirl amplitudes and whirl velocity. The larger whirl frequency and whirl amplitudes of the rotor, the greater the absolute value of aerodynamic work, and good suppression vibration effect of pocket damper seals.
引文
[1]Eldridge T M,Soulas T A.Mechanism and impact of damper seal clearance divergence on the rotordynamics of centrifugal compressors[C]//ASME Turbo Expo 2005:Power for Land,Sea,and Air.Reno,Nevada,USA:American Society of Mechanical Engineers,2005:907-915.
[2]Vannini G,Mazzali C,Underbakke H.Rotordynamic computational and experimental characterization of a convergent honeycomb seal tested with negative preswirl,high pressure with static eccentricity and angular misalignment[J].Journal of Engineering for Gas Turbines and Power,2016,139(5):052502.
[3]Childs D,Elrod D,Hale K.Annular honeycomb seals:Test results for leakage and rotordynamic coefficients;comparisons to labyrinth and smooth configurations[J].Journal of Tribology,1989,111(2):293-300.
[4]席文奎,许吉敏,张宏涛,等.迷宫密封对高参数转子系统稳定性的影响分析及公理设计方法应用[J].中国电机工程学报,2013,33(5):102-111.Xi Wenkui,Xu Jimin,Zhang Hongtao,et al.Investigation on influences of labyrinth seal on stability of high-parameter rotor system and application of axiomatic design method[J].Proceedings of the CSEE,2013,33(5):102-111(in Chinese).
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[6]Li Zhigang,Li Jun,Yan Xin.Multiple frequencies elliptical whirling orbit model and transient RANS solution approach to rotordynamic coefficients of annual gas seals prediction[J].Journal of Vibration and Acoustics,2013,135(3):031005.
[7]Li Z G,Li J,Feng Z P.Numerical investigations on the leakage and rotordynamic characteristics of pocket damper seals-Part I:Effects of pressure ratio,rotational speed,and inlet preswirl[J].Journal of Engineering for Gas Turbines and Power,2014,137(3):032503.
[8]Li J M,Aguilar R,AndréS L S,et al.Dynamic force coefficients of a multiple-blade,multiple-pocket gas damper seal:Test results and predictions[J].Journal of Tribology,2000,122(1):317-322.
[9]Eldin G,Mohamed A.Leakage and rotordynamic effects of pocket damper seals and see-through labyrinth seals[D].Texas,USA:Texas A&M University,2007.
[10]Ha T W,Choe B S.Numerical simulation of rotordynamic coefficients for eccentric annular-type-plain-pump seal using CFD analysis[J].Journal of Mechanical Science and Technology,2012,26(4):1043-1048.
[11]Subramanian S,Sekhar A S,Prasad B V S S S.Rotordynamic characteristics of rotating labyrinth gas turbine seal with centrifugal growth[J].Tribology International,2016,97:349-359.
[12]李志刚,陈尧兴,李军.高偏心率下旋转密封泄漏特性和静态动力特性研究[J].西安交通大学学报,2017,51(7):1-6.Li Zhigang,Chen Yaoxing,Li Jun.Investigation on the leakage and static dynamic characteristics of rotating seals at high eccentricity ratios[J].Journal of Xi'an Jiaotong University,2017,51(7):1-6(in Chinese).
[13]Pugachev A O,Griebel C,Tibos S,et al.Performance analysis of hybrid brush pocket damper seals using computational fluid dynamics[C]//ASME Turbo Expo:Turbomachinery Technical Conference and Exposition.Seoul,South Korea:American Society of Mechanical Engineers,2016.
[14]Vance J M,Li J M.Test results of a new damper seal for vibration reduction in turbomachinery[J].Journal of Engineering for Gas Turbines&Power,1996,118(4):843-846.
[15]Ertas B.Rotordynamic force coefficients of pocket damper seals[D].Texas,USA:Texas A&M University,2005.
[16]虞烈,刘恒.轴承–转子系统动力学[M].西安:西安交通大学出版社,2001:5-15.Yu Lie,Liu Heng.Dynamics of Bearing-Rotor System[M].Xi’an:Xi’an Jiaotong University Press,2001:5-15(in Chinese).
[17]钟一谔.转子动力学[M].北京:清华大学出版社,1987:43-44Zhong Yi’e.Rotordynamics[M].Beijing:Tsinghua University Press,1987:43-44(in Chinese).
[18]Childs D.Turbomachinery rotordynamics:phenomena,modeling,and analysis[M].New York:Wiley,1993:292-293.
[19]张强,何立东.蜂窝密封动力特性系数的计算方法[J].中国电机工程学报,2007,27(11):98-102.Zhang Qiang,He Lidong.Study on calculation of the dynamic coefficients of honeycomb seals[J].Proceedings of the CSEE,2007,27(11):98-102(in Chinese).
[20]Ertas B H,Delgado A,Vannini G.Rotordynamic force coefficients for three types of annular gas seals with inlet preswirl and high differential pressure ratio[J].Journal of Engineering for Gas Turbines and Power,2012,134(4):042503.
[2]Vannini G,Mazzali C,Underbakke H.Rotordynamic computational and experimental characterization of a convergent honeycomb seal tested with negative preswirl,high pressure with static eccentricity and angular misalignment[J].Journal of Engineering for Gas Turbines and Power,2016,139(5):052502.
[3]Childs D,Elrod D,Hale K.Annular honeycomb seals:Test results for leakage and rotordynamic coefficients;comparisons to labyrinth and smooth configurations[J].Journal of Tribology,1989,111(2):293-300.
[4]席文奎,许吉敏,张宏涛,等.迷宫密封对高参数转子系统稳定性的影响分析及公理设计方法应用[J].中国电机工程学报,2013,33(5):102-111.Xi Wenkui,Xu Jimin,Zhang Hongtao,et al.Investigation on influences of labyrinth seal on stability of high-parameter rotor system and application of axiomatic design method[J].Proceedings of the CSEE,2013,33(5):102-111(in Chinese).
[5]Vance J M,Schultz R R.New damper seal for turbomachinery[C]//Proceedings of the 14th Biennial ASME Design Technical Conference on Mechanical Vibration and Noise.Albuquerque,NM,USA:ASME,1993:139-148.
[6]Li Zhigang,Li Jun,Yan Xin.Multiple frequencies elliptical whirling orbit model and transient RANS solution approach to rotordynamic coefficients of annual gas seals prediction[J].Journal of Vibration and Acoustics,2013,135(3):031005.
[7]Li Z G,Li J,Feng Z P.Numerical investigations on the leakage and rotordynamic characteristics of pocket damper seals-Part I:Effects of pressure ratio,rotational speed,and inlet preswirl[J].Journal of Engineering for Gas Turbines and Power,2014,137(3):032503.
[8]Li J M,Aguilar R,AndréS L S,et al.Dynamic force coefficients of a multiple-blade,multiple-pocket gas damper seal:Test results and predictions[J].Journal of Tribology,2000,122(1):317-322.
[9]Eldin G,Mohamed A.Leakage and rotordynamic effects of pocket damper seals and see-through labyrinth seals[D].Texas,USA:Texas A&M University,2007.
[10]Ha T W,Choe B S.Numerical simulation of rotordynamic coefficients for eccentric annular-type-plain-pump seal using CFD analysis[J].Journal of Mechanical Science and Technology,2012,26(4):1043-1048.
[11]Subramanian S,Sekhar A S,Prasad B V S S S.Rotordynamic characteristics of rotating labyrinth gas turbine seal with centrifugal growth[J].Tribology International,2016,97:349-359.
[12]李志刚,陈尧兴,李军.高偏心率下旋转密封泄漏特性和静态动力特性研究[J].西安交通大学学报,2017,51(7):1-6.Li Zhigang,Chen Yaoxing,Li Jun.Investigation on the leakage and static dynamic characteristics of rotating seals at high eccentricity ratios[J].Journal of Xi'an Jiaotong University,2017,51(7):1-6(in Chinese).
[13]Pugachev A O,Griebel C,Tibos S,et al.Performance analysis of hybrid brush pocket damper seals using computational fluid dynamics[C]//ASME Turbo Expo:Turbomachinery Technical Conference and Exposition.Seoul,South Korea:American Society of Mechanical Engineers,2016.
[14]Vance J M,Li J M.Test results of a new damper seal for vibration reduction in turbomachinery[J].Journal of Engineering for Gas Turbines&Power,1996,118(4):843-846.
[15]Ertas B.Rotordynamic force coefficients of pocket damper seals[D].Texas,USA:Texas A&M University,2005.
[16]虞烈,刘恒.轴承–转子系统动力学[M].西安:西安交通大学出版社,2001:5-15.Yu Lie,Liu Heng.Dynamics of Bearing-Rotor System[M].Xi’an:Xi’an Jiaotong University Press,2001:5-15(in Chinese).
[17]钟一谔.转子动力学[M].北京:清华大学出版社,1987:43-44Zhong Yi’e.Rotordynamics[M].Beijing:Tsinghua University Press,1987:43-44(in Chinese).
[18]Childs D.Turbomachinery rotordynamics:phenomena,modeling,and analysis[M].New York:Wiley,1993:292-293.
[19]张强,何立东.蜂窝密封动力特性系数的计算方法[J].中国电机工程学报,2007,27(11):98-102.Zhang Qiang,He Lidong.Study on calculation of the dynamic coefficients of honeycomb seals[J].Proceedings of the CSEE,2007,27(11):98-102(in Chinese).
[20]Ertas B H,Delgado A,Vannini G.Rotordynamic force coefficients for three types of annular gas seals with inlet preswirl and high differential pressure ratio[J].Journal of Engineering for Gas Turbines and Power,2012,134(4):042503.