Performance estimation model of a torque converter part I: Correlation between the internal flow field and energy loss coefficient

The objective of this paper is to improve the performance estimation model of the internal flow field of a torque converter. Compared with performance experiment results, the converter based on the one-dimensional model does not satisfy the performance requirements demanded in practice. Therefore, we need to develop more predictable and reliable performance estimation models. In order to obtain shape information on three-dimensional blade geometry, a process of reverse engineering conducts a torque converter assembly, impeller, turbine and stator. In addition, a CFD simulation including mesh generation and post-processing was carried out to extract equivalent parameters from the internal flow field. The internal flow field can be explained by analyze the correlation between a performance estimation model and CFD analysis. The equivalent performance model adopts the variation of energy loss coefficients for a given operating condition according to the application of a changing energy loss coefficient by the least mean squares method. The estimated equivalent model improves the agreement in performance between experiments and the theoretical model. This model can reduce the error to within about 3 percent. Furthermore, this procedure for predicted performance achieves eminence in the estimation of the capacity factor.

[1]  T. Ishihara,et al.  Torque Converter as a Vibration Damper and Its Transient Characteristics , 1966 .

[2]  D. Hrovat,et al.  Bond graph modeling and computer simulation of automotive torque converters , 1985 .

[3]  Katsuro Fujitani,et al.  A Performance Prediction of Hydrodynamic Torque Converter , 1990 .

[4]  Marco Cigarini,et al.  Fluid Flow in an Automotive Torque Converter: Comparison of Numerical Results with Measurements , 1995 .

[5]  Tetsuo Kurahashi,et al.  Flow Visualization and Measurement of Torque Converter Stator Blades Using a Laser Sheet Lighting Method and a Laser Doppler Velocimeter , 1997 .

[6]  John E. Mahoney,et al.  Technology Needs for the Automotive Torque Converter—Part 1: Internal Flow, Blade Design, and Performance , 1988 .

[7]  Jang Moo Lee,et al.  Three Dimensional Flow Field Simulation to Estimate Performance of a Torque Converter , 2000 .

[8]  Klaus Brun,et al.  Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter: Part I—Average Measurements , 1996 .

[9]  Brad Pohl.  Transient Torque Converter Performance, Testing, Simulation and Reverse Engineering , 2003 .

[10]  V. J. Jandasek.  The Design of a Single-Stage Three-Element Torque Converter , 1961 .

[11]  Ken-ichi Abe,et al.  Three-Dimensional Simulation of the Flow in a Torque Converter , 1991 .

[12]  B. Lakshminarayana,et al.  Perspective: Fluid Dynamics and Performance of Automotive Torque Converters: An Assessment , 1996 .

[13]  Vamshi Korivi,et al.  Torque Converter CFD Engineering Part I: Torque Ratio and K Factor Improvement Through Stator Modifications , 2002 .

[14]  Budugur Lakshminarayana,et al.  Steady and Unsteady Flow Field at Pump and Turbine Exits of a Torque Converter , 1998 .