Average velocity measurements in six automotive torque converters: Part 1 - pump measurements

摘要

The internal flow fields of three automotive Plexiglas torque converter pumps with two different turbines were examined. A laser velocimeter was utilized to measure the velocity flow field at the pump mid- and exit planes in the six different geometry combinations; the stator was the same for all combinations. The pump geometries differed only by the exit blade angle while the turbine geometries differed only by the inlet 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 mid-plane, at low speed ratios the velocities are slightly higher near the suction surface but for the highest speed ratio a strong reverse flow is seen near the suction surface; at high speed ratios velocities were high near the shell. At the exit plane the flow is non-uniform in the blade-to-blade direction at all speed ratios. Velocities were fairly uniform in the core-to-shell direction at all speed ratios. Furthermore, through flow velocity non-uniformity became more pronounced as the speed ratio increased. Variations in turbine inlet blade angle minimally altered the pump mid- and exit plane velocities. Variations in the pump exit blade angle had no effects on the pump mid-plane velocity fields but did, however, significantly affect the exit plane flow fields. In particular, core-to-shell direction through flow velocity non-uniformity decreased with a corresponding decrease in pump exit blade angle while through flow velocity non-uniformity in the suction-to-pressure direction increased. The pump exit plane slip factors improved as the pump exit blade angle decreased. A counter-clockwise circulatory secondary flow pat tern at the pump mid-plane was observed for all geometries and, conversely, clockwise circulatory secondary flow patterns at the pump exit plane were recorded. Resulting vorticities were found to depend on geometries and speed ratios.