Average Velocity Measurements in Six Automotive Torque Converters Part II: Turbine Measurements

Abstract

The internal flow fields of two automotive Plexiglas torque converter turbines with three different pumps were examined. A laser velocimeter was utilized to measure the velocity flow field at the turbine inlet and mid-planes in the six different geometry combinations; the stator was the same for all combinations. The turbine geometries differed only by the inlet blade angle, while the pump geometries differed only by the exit blade angle. The torque converter was operated at three different turbine/pump rotational speed ratios: 0.065 (near stall), 0.600, and 0.800 (near coupling point). For all geometries at the inlet plane the flow is fairly uniform in the blade-to-blade direction at all speed ratios. Velocities are most uniform in the core-to-shell direction at high speed ratios, but high velocities move near the shell at lower speed ratios. At the mid-plane, at low speed ratios the velocities are significantly higher near the pressure surface but as the speed ratio increases, the gradient decreases. At low speed ratios velocities are higher near the shell but this distribution becomes uniform at higher speed ratios. In general the flow became more uniform as the speed ratio increased. Variations in the pump exit blade angle had effects on both inlet and mid-plane velocity distributions and are documented. Variations in turbine inlet blade angle altered the inlet and mid-plane flow fields, but less so than the pump variations. A clockwise circulatory secondary flow pattern at the turbine inlet plane was observed for all geometries and, conversely, counter-clockwise circulatory secondary flow patterns at the mid-plane were recorded. Resulting vorticities were found to depend on geometries and speed ratios. The turbine leading edge incidence angles were found to strongly depend on the speed ratio, ranging from positive to negative, as well as pump and turbine blade angles.

Presented as a Society of Tribologists and Lubrication Engineers Paper at the STLE/ASME Tribology Conference in San Francisco, CA October 21–24, 2001

KEY WORDS:

• Torque Converters
• Squeeze-Film
• Bearings

Notes

Presented as a Society of Tribologists and Lubrication Engineers Paper at the STLE/ASME Tribology Conference in San Francisco, CA October 21–24, 2001