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Development of the Variable Parametric Performance Model of Torque Converter for the Analysis of the Transient Characteristics of Automatic Transmission  

임원식 (서울산업대학교 자동차공학과, 서울사업대 정밀기계기술연구소)
이진원 (서울대학교 대학원)
Publication Information
Transactions of the Korean Society of Automotive Engineers / v.10, no.1, 2002 , pp. 244-254 More about this Journal
Abstract
To enhance the acceleration performance and fuel consumption rate of a vehicle, the torque converter is modified or newly-developed with reliable analysis model. Up to recently, the one dimensional performance model has been used for the analysis and design of torque converter. The model is described with constant parameters based on the concept of mean flow path. When it is used in practice, some experiential correction factors are needed to minimize tole estimated error. These factors have poor physical meaning and cannot be applied confidently to the other specification of torque converter. In this study, the detail dynamic model of torque converter is presented to establish the physical meaning of correction factors. To verify the validity of model, performance test was carried out with various input speed and oil temperature. The effect of oil temperature on the performance is analysed, and it is applied to the dynamic model. And, to obtain the internal flow pattern of torque converter, CFD(Computational Fluid Dyanmics) analysis is carried out on three-dimensional turbulent flow. Correction factors are determined from the internal flow pattern, and their variation is presented with the speed ratio of torque converter. Finally, the sensitivity of correction factors to the speed ratio is studied for the case of changing capacity factor with maintaining torque ratio.
Keywords
Torque converter; Design path; Stall; Equivalent flow angle; Capacity factor; Forced vortex theorem; Correction factor;
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  • Reference
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