Quantification of primary flows of a torque converter using laser doppler velocimetry 2000-05-0106
All modern automotive automatic transmissions require the use of
a torque converter to allow for the transmission of torque from the
engine to the drivetrain. Although they are commonly used
throughout the automotive industry, there is little understanding
of the internal flows within the torque converter. An experimental
study has been conducted to reveal the internal flow
characteristics within a production torque converter using Laser
Doppler Velocimetry (LDV) under the operating conditions.
LDV measurements were conducted on the planes between impeller
blades, and the gap between the impeller and turbine blades. The
study showed that the internal flow is highly complex and the
difference in rotor speeds between the impeller and turbine
compound the flow effects. Transmission oil flows in the planes at
the impeller exit and gap region were affected by the turbine blade
as it passed. Transmission oil flow was also found to be leaving
the impeller and flowing over the turbine into behind the turbine
back plate. This affected the converter efficiency negatively.
This study has led to a better understanding of flow mechanism
within the torque converter and provided the guidance needed for
the advancement of improved computational fluid dynamic models.
Keunchul C. Lee, Seoung-Chool Yoo, Harold J. Schock
University of Alabama, Halla Institute of Technology, Michigan State Univ.