Rheological Properties of Torque Converter Media and Applicability of Three-dimensional Vortex Identification Method

doi:10.3901/JME.2025.18.406

Abstract

Abstract: The non-stationary multiscale eddy dynamics inside the torque converter governs and influences the evolution of its flow field structure. Based on the theory of computational fluid dynamics, the stress-blended eddy simulation(SBES) is used to numerically simulate the flow field of the torque converter in oil medium and water medium under the stall condition, to compare and analyse the similarity and difference of the flow field structure in different media, and to comprehensively evaluate the feasibility of carrying out a scientific study of the flow field evolution law in water medium. The accuracy of the simulation results in aqueous medium is verified by particle image velocimetry(PIV) visualisation test. Different vortex identification methods are used to extract the non-constant multi-scale vortex structure of the torque converter, and the different vortex identification methods are analysed and evaluated in terms of the overall reconstruction effect of the flow channel space and the identification of the turbulent local structure of the near-wall surface of the blade. The results show that：① Q criterion threshold selection blindness, vortex reconstruction effect depends on experience；Ω method vortex reconstruction effect is good, but for the blade near the wall region of the multi-scale vortex identification ability is weak, weak vortex structural features are lost；Ω-Liutex method spatial multi-scale vortex reconstruction effect is the best, strong vortex, weak vortex structural details feature extraction ability, threshold selection sensitivity is low, vortex reconstruction efficiency is high. ② The simulation results of the overall flow field of oil medium and water medium are highly similar, but due to the influence of medium viscosity, there are differences in the local flow field characteristics of the near-wall surface of the blade, and the vortex system reconstruction of the oil medium is more full, and the continuity of the flow between impellers is stronger. The results of the study can provide certain technical guidance for the analysis of the flow field evolution law of the torque converter and the forward design of the blade grid structure.

Key words: torque converter, computational fluid dynamics, particle image velocimetry, vortex identification method, threshold selection

CLC Number:

TH137

ZHENG Qiulin, CHAI Bosen, GENG Dongni, FAN Wenhe, LI Tao, RAN Zilin. Rheological Properties of Torque Converter Media and Applicability of Three-dimensional Vortex Identification Method[J]. Journal of Mechanical Engineering, 2025, 61(18): 406-416.

References

[1] 魏巍，闫清东. 液力元件设计[M]. 北京：北京理工大学出版社，2015. WEI Wei，YAN Qingdong. Design of hydraulic components[M]. Beijing：Beijing Institute of Technology Press，2015.
[2] 吴光强，陈洁. 乘用车液力变矩器优化设计研究综述[J]. 汽车工程，2020，42(8)：1090-1096，1123. WU Guangqiang，CHEN Jie. Summary of research onoptimal design of torque converters for passenger vehicles[J]. Automotive Engineering，2020，42(8)：1090-1096，1123.
[3] 马文星. 现代机械设计手册液力传动设计单行本[M]. 2版. 北京：化学工业出版社，2020. MA Wenxing. Modern mechanical design manual hydraulic transmission design monobook[M]. 2nd ed. Beijing：Chemical Industry Press，2020.
[4] 马文星，王佳欣，刘春宝. 液力变矩器流动数值模拟的发展与应用[J]. 液压与气动，2019(5)：1-8. MA Wenxing，WANG Jiaxin，LIU Chunbao. Development and application of numerical simulation of flow in torque converters[J]. Hydraulics and Pneumatics，2019(5)：1-8.
[5] EDWARD D J R，MARK W，DARRELL R，et al. Torque and pressure CFD correlation of a torque converter[J]. SAE International Journal of Passenger Cars：Mechanical Systems，2019，12(3)：1-12.
[6] SCHWEITZER J，GANDHAM J. Computational fluid dynamics in torque converters：Validation and application[J]. International Journal of Rotating Machinery，2003，9(6)：411-418.
[7] YAMAMOTO F， WADA A，IGUCHI M，et al. Torque converter internal flow：Visualization and image processing[J]. Journal of Flow Visualization and Image Processing，2017，24(1)：203-214.
[8] GUO Meng，LIU Cheng，ZHANG Jiahua，et al. Thermal effect on cavitation characteristics of a hydraulic torque converter[J]. Numerical Heat Transfer，2022，82(1-2)：31-52.
[9] 赵斌娟，谢昀彤，廖文言，等. 第二代涡识别方法在混流泵内部流场中的可靠性分析[J]. 机械工程学报，2020，56(14)：216-223. ZHAO Binjuan，XIE Yuntong，LIAO Wenyan，et al. Applicability analysis of the second generation vortex identification method in the internal flow field of mixed-flow pump[J]. Journal of Mechanical Engineering，2020，56(14)：216-223.
[10] 刘春宝，李静，徐志轩，等. 液力变矩器热流动尺度解析模拟与特性精确预测[J]. 机械工程学报，2018，54(18)：146-153. LIU Chunbao，LI Jing，XU Zhixuan，et al. Scale-resolving simulation of thermal flow and accurate performance prediction in hydrodynamic torque converter[J]. Journal of Mechanical Engineering，2018，54(18)：146-153.
[11] 刘超群. Liutex-涡定义和第三代涡识别方法[J]. 空气动力学学报，2020，38(3)：413-431，478. LIU Chaoqun. Definition of liutex-vortex and identification method of the third generation vortex[J]. Chinese Journal of Aerodynamics，2020，38(3)：413-431，478.
[12] 柴博森，张进，吕恒升，等. 液力偶合器三维涡识别方法及流场时空演化[J]. 农业工程学报，2022，38(12)：32-40. CHAI Bosen，ZHANG Jin，Lü Hengsheng，et al. Three dimensional vortex identification method of hydraulic coupling and sp atiotemporal evolution of flow field[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE)，2022，38(12)：32-40.
[13] 柴博森，丛皓，杨昊旻，等. 液力变矩器导轮叶片出口角对性能的影响分析[J]. 机械工程学报，2024，60(11)：105-114. CHAI Bosen，CONG Hao，YANG Haomin，et al. Analysis of influence of stator blade outlet angle on performance of torque converter[J]. Journal of Mechanical Engineering，2024，60(11)：105-114.
[14] HUNT J C R，WRAY A A，MOIN P. Eddies，streams，and convergence zones in turbulent flows[J]. Center for Turbulence Research Proceedings of the Summer Program，1988：193-208.
[15] 王义乾，桂南. 第三代涡识别方法及其应用综述[J]. 水动力学研究与进展(A辑)，2019，34(4)：413-429. WANG Yiqian，GUI Nan. A review of third-generatio n vortex identification methods and their applications[J]. Hydrodynamics Research and Progress(Series A)， 2019，34(4)：413-429.
[16] DONG Xiangrui，GAO Yisheng，LIU Chaoqun. New normalized rortex/vortex identification method[J]. Physics of Fluids，2019，31(1)：011701.
[17] LIU Chaoqun，GAO Yisheng，DONG Xiangrui，et al. Third generation of vortex identification methods：Omega and liutex/rortex based systems[J]. Journal of Hydrodynamics，2019，31(2)：205-223.
[18] LIU Chaoqun， WANG Yiqian， YANG Yong，et al. New omega vortex identification method[J]. Mechanics & Astronomy，2016，59(8)：62-70.
[19] LIU Jiaming，LIU Chaoqun. Modified normalized rortex/vortex identification method[J]. Physics of Fluids，2019，31(6)：061704.
[20] 柴博森，王广义，朱国仁，等. 制动工况下液力变矩器大涡模拟流场仿真及可视化试验验证[J]. 华南理工大学学报(自然科学版)，2022，50(3)：95-105. CHAI Bosen，WANG Guangyi，ZHU Guoren，et al. Large eddy simulation flow field analysis and visualization test verification of hydraulic torque converter under braking condition[J]. Journal of South China University of Technology(Natural Science Edition)，2022，50(3)：95-105.
[21] 柴博森，王玉建，刘春宝，等. 基于粒子图像测速技术的液力变矩器涡轮内流场测试与分析[J]. 农业工程学报，2015，31(12)：96-98. CHAI Bosen，WANG Yujian，LIU Chunbao，et al. Test and analysis of internal flow field in turbine of hy‐drodynamic torque converter based on particle image velocimetry[J]. Transactions of the Chinese Society of Agricultural Engineering，2015，31(12)：96-98.