Velocity Measurements In an Automotive Torque Converter—Part II: Average Turbine and Stator Measurements

Abstract

Laser velocimetry was used to measure the flow field in the turbine and stator of an automotive torque converter. The data complements that of data in a pump at the same operating conditions. Average velocities are presented and analyzed in this paper for three turbine/pump speed ratios (0.065, 0.600, and 0.800). Data presented in this paper embody the most detailed velocity measurements in torque converters available. At all speed ratios and in all turbine measurement planes the highest through flow velocities generally occurred at the pressure side of the channel. At the turbine inlet a velocity deficit near the core was observed. This is due to the velocity deficit at the pump exit that transmits to the turbine inlet. At the lowest speed ratio flow entered the turbine with significant “pre-swirl” causing the flow to separate on the suction surface between the inlet and the mid-plane, resulting in a separation region in the core-suction quadrant. Strong circulatory secondary flows were not observed in the turbine planes as they were in the pump planes. The measured vorticity was highest at the inlet plane. The torque distribution was found between the inlet and mid-planes and mid- and exit planes of the turbine. The chord wise distribution was uneven and most of the torque was derived from the fluid between the inlet and mid-plane. The stator flow field is relatively uniform at the inlet at the highest speed ratio but much less so at the lower speed ratios. Some separation is seen at the lowest speed ratio at the inlet. At the highest speed ratio flow enters the stator with little incidence to the blades. At lower speed ratios significant incidence was measured resulting in separation on the suction surface. For the highest two speed ratios a significant separation region was observed at the exit plane in the suction/shell quadrant of the stator. The torque distribution was found between the stator inlet and mid-planes and mid- and exit planes. The total torque delivered to the working fluid at the 0.065 speed ratio is significant, indicating the presence of torque multiplication. At the 0.800 speed ratio the torque distribution between all planes is minimal, indicating minimal torque multiplication. The chord-wise torque distribution is relatively even. Presented at the 54th Annual Meeting Las Vegas, Nevada May 23–27, 1999