Velocity Measurements in an Automotive Torque Converter Part I—Average Pump Measurements

Abstract

The flow field in the inlet, mid- and exit planes of the pump of an automotive torque converter was measured using laser velocimetry. Three turbine/pump speed ratios (0.065, 0.600, and 0.800) were tested and average velocities are presented and analyzed. Data presented in this paper embody the most detailed velocity measurements in torque converters available. The highest through flow velocities generally occurred at the shell side of the blades in all measurement planes and at all speed ratios. For all speed ratios the flow entered the pump inlet plane with a velocity deficit occurring at the core side. The flow was able to become more uniform before it reached the mid-plane at the speed ratio of 0.065, while at the higher speed ratios the flow field demonstrated a large separation region at the mid-plane in the suction side/core quadrant. The flow field was more uniform in the exit plane at all speed ratios and separation was not observed. The secondary flow in the pump mid-plane is counter-clockwise. On the other hand, the secondary flow in the pump exit plane is clockwise. Rotational secondary flows were not observed in the inlet plane. The slip factor was determined at the mid- and exit planes and compared to predicted values for conventional centrifugal pumps. At the mid-plane the values compared well with previous correlations. However, at the exit plane the slip factors for the torque converter pump were higher than for a centrifugal pump. The torque distribution was found between the inlet and mid-planes and mid- and exit planes. The chord-wise distribution was uneven and more torque was delivered to the fluid between the mid- and exit plane. Presented at the 54th Annual Meeting Las Vegas, Nevada May 23–27, 1999