Numerical simulation of pressure distribution in bristle seal for turbomachinery
KANG Yuchi 1,2, LIU Meihong1*, WANG Xueliang1, TAN Yongfa1, LIU Jinbin1
1.Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650504, China; 2.Department of Mechanical Engineering, Blekinge Institute of Technology, Karlskrona, Blekinge 37179, Sweden
Abstract：In order to further study the pressure distribution in bristle seals, a uniformed two-dimensional closed staggered tube bundle model representing a bristle pack cross-section was proposed and the fluid flow through the bundle was solved by computational fluid dynamics(CFD)method. Accor-ding to the critical Reynolds number for boundary layer transition, a new method was proposed to decide the fluid flow regime in the bundle. The pressure and velocity distributions in the bundle were studied under various pressure differentials across the seal. The influences of distance between bristles and number of circumferential bristle rows on the pressure distribution were tackled. It is shown that the pressure distributions in the uniformed two-dimensional closed staggered tube bundle model agrees well with the previous experimental data. The pressure distributions are like “V”, while the velocity distributions are like the inverted “V”. The pressure borne by the rear 1/3 part of the bristle pack is higher than that by the front 2/3 part. Moreover, the percentage of the pressure differential borne by the last 5 bristle rows increases with increasing total pressure differential. The pressure differential borne by the last bristle row is higher than that by a few rows in front of it. A reduced distance between bristles can allow the pressure to be distributed more even from one row to another. Bristles equally spaced can ensure an even pressure distribution rather well. Increasing the number of rows can also have the same effect.
康宇驰,, 刘美红*, 王学良, 谭永发, 刘晋宾. 透平刷式密封压力分布数值模拟[J]. 排灌机械工程学报, 2018, 36(5): 420-425.
KANG Yuchi ,, LIU Meihong*, WANG Xueliang, TAN Yongfa, LIU Jinbin. Numerical simulation of pressure distribution in bristle seal for turbomachinery. Journal of Drainage and Irrigation Machinery Engin, 2018, 36(5): 420-425.
[1]林基恕, 张振波. 21世纪航空发动机动力传输系统的展望[J]. 航空动力学报, 2001, 16(2):108-114. LIN Jishu, ZHANG Zhenbo. Prospects of aeroengine power transmission system in the 21st Century[J]. Journal of aerospace power,2001, 16(2):108-114.(in Chinese)[2]MANDHANI V K, CHHABRA R P, ESWARAN V. Forced convection heat transfer in tube banks in cross flow[J]. Chemical engineering science, 2002, 57(3):379-391.[3]刘喜岳, 张靖周, 李刚团,等. 双U型管束模型换热器的流动和传热特性[J]. 航空学报, 2015, 36(12):3832-3842. LIU Xiyue,ZHANG Jingzhou,LI Gangtuan, et al. Flow and heat performance of double U-shaped-tubes mo-deled heat exchanger [J]. Acta aeronautica et astronautica sinica, 2015, 36(12):3832-3842.(in Chinese)[4]戴伟. 刷式密封泄漏流动及接触传热的数值分析[D]. 上海:上海交通大学, 2011.[5]黄首清, 索双富, 李永健,等. 基于2维叉排管束模型的刷式密封介质流动计算[J]. 清华大学学报(自然科学版), 2016,56(2):160-166. HUANG Shouqing,SUO Shuangfu,LI Yongjian, et al. Flows in brush seals based on a 2-D staggered tube bundle model[J]. Journal of Tsinghua University(science and technology),2016,56(2): 160-166.(in Chinese)[6]王之栎, 郭苗苗, 李理科. 刷密封刷丝力学行为与密封性能[J]. 北京航空航天大学学报, 2011, 37(10):1218-1222. WANG Zhili,GUO Miaomiao,LI Like. Mechanical behaviors of brush seals and sealing performance[J]. Journal of Beijing University of Aeronautics and Astronautics, 2011, 37(10):1218-1222.(in Chinese)[7]SCHWARZ H, FRIEDRICHS J. Preliminary investigations for a pressure balanced back plate at low inclined brush seals[C]//Proceedings of the ASME turbo expo 2015: turbine technical conference and exposition,2015.[8]SUN D, LIU N N, FEI C W, et al. Theoretical and numerical investigation on the leakage characteristics of brush seals based on fluid-structure interaction[J]. Aerospace science & technology, 2016, 58:207-216.[9]丁祖荣. 流体力学(上册)[M]. 北京:高等教育出版社, 2003.[10]DOGU Y, AKSIT M F. Brush seal temperature distribution analysis[J]. Journal of engineering for gas turbines & power, 2006, 128(3):1237-1248.[11]CENGEL Y A. Heat & mass transfer: a practical approach[M].北京:高等教育出版社, 2007.[12]杨烁,吴宝山. 二维圆柱绕流数值模拟[J]. 中国造船,2007, 48(S1): 533-540. YANG Shuo,WU Baoshan. The numerical simulation of two dimensional circular flow[J]. Shipbuilding of China,2007, 48(S1): 533-540.(in Chinese)[13]BAYLEY F J, LONG C A. A combined experimental and theoretical study of flow and pressure distributions in a brush seal[C]//Proceedings of the 37th International Gas Turbine and Aeroengine Congress and Exposition, 1992.[14]陈文曲. 二维串并列圆柱绕流与涡致振动研究[D].杭州:浙江大学, 2005.
