High-temperature and High-speed Air Film Floating Ring Seal Constant Clearance Design and Leakage Analysis

doi:10.3901/JME.260420

Abstract

Abstract: Under high-temperature and high-speed conditions, the air film floating ring seal experiences a significant change in clearance size. This change makes it difficult to meet low leakage requirements and seriously affects the seal’s performance and stability. Aiming to seal a bearing cavity in an engine, a design method for a“constant clearance”air film floating ring seal structure that is suitable for all working conditions is proposed. Furthermore, a high-precision method for calculating leakage, considering pressure loss with various film thicknesses under clearance eccentricity conditions, is also being explored. A numerical analysis model of fluid-solid-thermal coupling is established to discuss the comprehensive influence of the floating ring structure, mounted ring, and rotor material combination on the sealing clearance with changes in rotational speed and temperature. The model aims to analyze the leakage characteristics and utilize operational tests of the floating ring seal to verify the performance of the seal with a "constant clearance" and the accuracy of the numerical analysis model. The results indicate that the combination of the mounted ring and rotor material, along with the outer diameter and thickness of the mounted ring, are the most significant factors influencing the seal clearance under varying temperatures and speeds. The level of interference in the outer diameter of the graphite ring only impacts the initial seal clearance and the temperature at which failure occurs. After a thorough optimization of design and material selection, the constant-clearance air film floating ring seal can reduce clearance fluctuation by 90% compared to the ordinary floating ring under high-temperature and high-speed working conditions. The working clearance is the primary factor that affects the sealing performance. The leakage rate of a constant clearance air film floating ring seal is approximately proportional to the differential pressure and outlet pressure, and inversely proportional to the temperature. The rotational speed affects the eccentricity, which, in turn, causes fluctuations in the leakage rate. The conclusions of the study provide a dependable theoretical foundation for achieving high stability, long lifespan, and low leakage operation of air film floating ring seals under high-temperature and high-speed working conditions.

Key words: constant clearance, structural design, material selection, pressure loss, leakage characteristics

CLC Number:

TH113
TH117

ZHU Shuhai, LI Shuangxi, MA Runmei, ZHANG Shuyao. High-temperature and High-speed Air Film Floating Ring Seal Constant Clearance Design and Leakage Analysis[J]. Journal of Mechanical Engineering, 2026, 62(9): 281-290.

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URL: http://www.cjmenet.com.cn/EN/10.3901/JME.260420

http://www.cjmenet.com.cn/EN/Y2026/V62/I9/281

References

[1] 施任杰，郑娆，李双喜，等. 压力扰动下气膜浮环密封的瞬态稳定性研究[J]. 机电工程，2021，38(3)：325-330. SHI Renjie，ZHENG Rao，LI Shuangxi，et al. Study on transient stability of gas film floating ring seals under pressure disturbance[J]. Journal of Mechanical & Electrical Engineering，2021，38(3)：325-330.
[2] 施任杰. 镶装式气膜浮环密封的温度场分析和动态性能研究[D]. 北京：北京化工大学，2021. SHI Renjie. Temperature field analysis and dynamic performance study of inlaid gas film floating ring seals[D]. Beijing：Beijing University of Chemical Technology，2021.
[3] 夏鹏，刘占生. 浮环密封结构弹性对间隙泄漏量和动力学系数的影响[J]. 推进技术，2017，38(12)：2815-2821. XIA Peng，LIU Zhansheng. Influence of floating ring seal structure elasticity on clearance leakage and dynamic coefficients[J]. Journal of Propulsion Technology，2017，38(12)：2815-2821.
[4] 马利军，李双喜，蔡纪宁，等. 高温镶装式浮环密封的径向间隙研究[J]. 润滑与密封，2018，43(6)：90-95. MA Lijun，LI Shuangxi，CAI Jining，et al. Research on radial clearance of high-temperature inlaid floating ring seals [J]. Lubrication Engineering，2018，43(6)：90-95.
[5] 马利军. 高温镶装式气膜浮环密封性能研究[D]. 北京：北京化工大学，2018. MA Lijun. Study on the performance of high-temperature inlaid gas film floating ring seals[D]. Beijing：Beijing University of Chemical Technology，2018.
[6] 张杰，李鲲，吴兆山，等. 镶装式石墨密封环的压力变形研究[J]. 润滑与密封，2012，37(3)：53-58. ZHANG Jie，LI Kun，WU Zhaoshan，et al. Study on pressure deformation of inlaid graphite sealing rings[J]. Lubrication Engineering，2012，37(3)：53-58.
[7] 李婕，蔡纪宁，张秋翔，等. 镶装式密封环过盈量的研究[J]. 润滑与密封，2009，34(11)：68-71. LI Jie，CAI Jining，ZHANG Qiuxiang，et al. Study on interference fit of inlaid sealing rings[J]. Lubrication Engineering，2009，34(11)：68-71.
[8] 胡廷勋，周坤，王晓燕，等. 浮环密封泄漏特性数值计算与试验[J]. 航空动力学报，2020，35(4)：888-896. HU Tingxun，ZHOU Kun，WANG Xiaoyan，et al. Numerical calculation and experiment on leakage characteristics of floating ring seals[J]. Journal of Aerospace Power，2020，35(4)：888-896.
[9] 胡廷勋，王晓燕，周坤，等. 温度对浮环密封泄漏特性的影响[J]. 推进技术，2022，43(4)：55-61. HU Tingxun，WANG Xiaoyan，ZHOU Kun，et al. Influence of temperature on leakage characteristics of floating ring seals[J]. Journal of Propulsion Technology，2022，43(4)：55-61.
[10] FUKUI S，KANEKO R. Analysis of ultra-thin gas film lubrication based on linearized Boltzmann equation：First report—derivation of a generalized lubrication equation including thermal creep flow[J]. Journal of Tribology，1988，110(2)：253-261.
[11] FUKUI S，KANEKO R. A database for interpolation of poiseuille flow rates for high knudsen number lubrication
problems[J]. Journal of Tribology，1990，112(1)：78-83.
[12] TAYLOR C M，DOWSON D. Turbulent lubrication theory—application to design[J]. Journal of Lubrication Technology，1974，96(1)：36-46.
[13] CONSTANTINESCU V N. Basic relationships in turbulent lubrication and their extension to include thermal effects[J]. Journal of Lubrication Technology，1973，95(2)：147.
[14] DUAN W，CHU F，KIM C-H，et al. A bulk-flow analysis of static and dynamic characteristics of floating ring seals[J]. Tribology International，2007，40(3)：470-478.
[15] 陈志，高春阳，范唯超，等. 浮环密封流场数值模拟及泄漏率公式的修正[J]. 四川大学学报，2016，48(1)：208-214. CHEN Zhi，GAO Chunyang，FAN Weichao，et al. Numerical simulation of flow field in floating ring seals and correction of leakage rate formula[J]. Journal of Sichuan University，2016，48(1)：208-214.
[16] TOKUNAGA Y，INOUE H，HIROMATSU J，et al. Rotordynamic characteristics of floating ring seals in rocket turbopumps[J]. International Journal of Fluid Machinery and Systems，2016，9(3)：194-204.
[17] 王伟，赵宗坚，张振生. 单环圆周密封装置设计和应用研究[J]. 航空发动机，2009，35(4)：7-11. WANG Wei，ZHAO Zongjian，ZHANG Zhensheng. Design and application research of single-ring circumferential sealing device[J]. Aeroengine，2009，35(4)：7-11.
[18] 马也. 整体式气膜浮环密封的开启性能与泄漏特性研究[D]. 北京：北京化工大学，2020. MA Ye. Study on opening performance and leakage characteristics of integral gas film floating ring seals[D]. Beijing：Beijing University of Chemical Technology，2020.