为揭示高转速下盘腔旋流与旋转雷诺数对轮缘封严性能的影响机理，对轮缘封严计算模型进行了三维定常数值模拟，并通过实验数据与数值计算对比，验证了所用数值方法在计算盘腔流动与封严性能方面的有效性。在此基础上，研究了不同盘腔进口冷气旋转比与旋转雷诺数条件下盘腔内的流场分布，并采用附加变量法分析了腔内封严效率的变化规律。结果表明：冷气旋转比与旋转雷诺数的变化均会对盘腔流场产生显著影响从而改变封严性能；定封严冷气流量条件下，盘腔进口冷气旋转比增大会提高腔内总压，使腔内动静盘壁面高半径位置的封严效率上升，旋转比由0.36增大到1.08，高半径区域静盘封严效率增大6.4%；定封严间隙条件下，增大旋转雷诺数会使腔内漩涡向高半径方向与动盘侧迁移，经过盘腔出口位置时会因卷吸主流燃气造成燃气入侵现象加剧。旋转雷诺数由1.39×10e6增大到4.87×10e6，封严效率呈现先降低后升高的趋势，静盘壁面封严效率降幅最高可达71.7%。
To elucidate the mechanisms underlying the influence of swirl flow and rotational Reynolds number on sealing perfor-mance at high rotational speed, this paper presents a three-dimensional steady simulation of a rim seal model. The validity of the employed numerical method in computing cavity flow and sealing performance is verified through com-parisons between experimental data and numerical calculations. On this foundation, the flow field distribution within the cavity under varying conditions of swirl ratio and rotational Reynolds number is investigated. Furthermore, the variation in sealing efficiency is analyzed using the additional passive tracer method. The results reveal that changes in both the swirl ratio and the rotational Reynolds number exert significant impacts on the cavity flow field, thereby altering the seal performance. Under conditions of constant cooling flow rate, cooling flow swirl ratio increases will increase the total pressure in the cavity, resulting in an enhancement of the sealing efficiency at the high-radius locations of both the ro-tating and static walls. Specifically, as the swirl ratio increases from 0.36 to 1.08, the sealing efficiency of the static wall in the high-radius region increases by 6.4%. Under conditions of constant sealing clearance, increasing the rotational Reynolds number causes the vortex within the cavity to migrate towards the high-radius direction and the side of the rotating wall. When passing through the sealing clearance, the vortex entrains the mainstream gas, exacerbating the phenomenon of gas ingestion. As the rotational Reynolds number increases from 1.39×10e6 to 4.87×10e6, the sealing efficiency exhibits a trend of initial decrease followed by increase, with the maximum decrement in sealing efficiency of the static wall reaching 71.7%.
[1]Aqiang Lin, Gaowen Liu, Ran Chang, et al.Com-prehensive evaluations of heat transfer performance with conjugate heat dissipation effect in high-speed ro-tating free-disk system of aero-engines[J].Funda-mental Research, 2022, 2(5):1-13
[2]Aqiang Lin, Gaowen Liu, Pengfei Li, et al.Theoretical and experimental evaluations of pre-swirl rotor-stator system with inner seal bypass configuration for turbine performance improvement[J].Energy, 2022, 258(0):124760-0
[3]贾兴运.涡轮转静盘腔燃气入侵及封严机理研究[D]. 哈尔滨: 哈尔滨工程大学, 2019.
[4]Behr T.Kalfas AI.,Abhari R. S. Unsteady flow phys-ics and performance of a one-and-12-stage unshrouded high work turbine[J].Journal of Turbomachinery, 2007, 129(2):348-359
[5]Schuepbach P.Abhari RS.,Rose M. G.,et al. Effects of suction and injection purge-flow on the secondary flow structures of a high-work turbine[J].Journal of Turbomachinery, 2010, 132(2):1-8
[6]Hualca F.P., Horwood J.T., Sangan C. M. The effect of vanes and blades on ingress in gas turbines[C]. Phoenix: ASME Turbo Expo: Turbomachinery Technical Con-ference and Exposition, 2019: V05BT15A008.
[7]Owen J.M. Prediction of ingestion through turbine rim seals — Part II: Externally induced and combined in-gress[J].Journal of Turbomachinery, 2011, 133(3):031006-0
[8]Sangan C.M., Pountney O. J., Zhou K., et al. Experi-mental measurements of ingestion through turbine rim seals. Part I: Externally-Induced ingress[C]. Vancouver: ASME Turbo Expo, 2011: 1-13.
[9]Wang R, Du Q, Liu G, et al.Influence of secondary sealing flow on performance of turbine axial rim seals[J].Journal of Thermal Science, 2020, 29(3):840-851
[10]Green B.R.,Mathison RaM.,Dunn M. G. Time-averaged and time-accurate aerodynamic effects of forward rotor cavity purge flow for a high-pressure tur-bine — Part I: Analytical and down-loaded experi-mental comparisons[J].Journal of Turbomachinery, 2014, 136(1):011004-0
[11]Green B.R.,Mathison RaM.,Dunn M. G. Time-averaged and time-accurate aerodynamic effects of ro-tor purge flow for a modern,one and one-half stage high-pressure turbine — Part II: Analytical flow field analysis[J].Journal of Turbomachinery, 2014, 136(1):011009-0
[12]Zlatinov M.B.,Tan CS.,Montgomery M.,et al. Tur-bine hub and shroud sealing flow loss mechanisms[J].Journal of Turbomachinery, 2012, 134(6):061027-0
[13]杨帆, 周莉, 王占学.轮缘封严气流与主流干涉的损失机理研究[J].推进技术, 2020, 41(2):285-292
[14]田淑青, 陶智, 丁水汀，等.轴向通流旋转盘腔内类Rayleigh-Benard对流稳定性研究[J].热科学与技术, 2003, 0(03):260-265
[15]田淑青, 陶智, 丁水汀，等.轴向通流旋转盘腔内流动不稳定性研究[J].北京航空航天大学学报, 2005, 0((04)):393-396
[16]张晶辉，马宏伟.涡轮盘腔轴向封严流动的数值研究[J].航空动力学报, 2014, 29(04):927-934
[17]何振鹏，周佳星，王宇博，等.级涡轮前后轮缘密封封严流动特性研究[J].推进技术, 2022, 43(05):142-149
[18]杨帆, 周莉, 王占学.轮缘封严气流与主流涡系交互作用的非定常数值研究[J].推进技术, 2019, 40(2):315-323
[19]杨帆, 周莉, 王占学.轮缘封严气流与转子干涉损失机理的数值研究[J].推进技术, 2018, 39(11):2481-2489
[20]高庆, 陶加银, 宋立明, 等.涡轮轮缘密封封严效率的数值研究[J].西安交通大学学报, 2013, 47(05):12-17
[21]吴康, 任静, 蒋洪德等.整级透平中转静轮缘封严问题研究 : 封严与入侵[J].工程热物理学报, 2014, 35(5):873-877
[22]高庆, 李军.径向轮缘密封封严效率的数值研究[J].西安交通大学学报, 2014, 48(9):55-61
[23]王启杰.对流传热传质分析[M]. 西安: 西安交通大学出版社, 1991.
[24]Sangan C.Measurement of ingress through gas turbine rim seals[D]. Bath: University of Bath, 2011: 89-95.
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