Experimental Investigation of Steady and Unsteady Flow Field Upstream and Downstream of an Automotive Torque Converter Pump

Abstract

The objective of this investigation is to understand the steady and the unsteady flow field at the exit of an automotive torque converter pump with a view towards improving its performance. The measurements were conducted in a stationary frame of reference using a high frequency response five-hole probe and the data were processed to derive the flow properties in the relative (pump) frame of reference. The experimental data were processed at three different operating conditions: maximum efficiency point, design point and near-stall point. The unsteady values of flow properties (pressure, velocity and flow angles) were divided into five components: mean, periodic, blade aperiodic, revolution aperiodic and unresolved components.The velocity profiles indicate zones of separation near the core region at speed ratio (SR) 0.8. This zone is transported to the shell region at SR 0.065 due to the presence of a strong secondary vortex. The secondary vortex (weak) for the SR 0.8 rotates anti-clockwise, and is located only near core-wake region. The secondary vortex (strong) at SR 0.065 rotates clockwise, and encompasses the entire passage. The unsteady flow data show that unresolved and periodic components dominate the unsteadiness at the pump exit. The overall aperiodicity is negligible and is dominated by the blade aperiodic component.