EXPERIMENTAL INVESTIGATION OF STEADY AND UNSTEADY-FLOW FIELD DOWNSTREAM OF AN AUTOMOTIVE TORQUE CONVERTER TURBINE AND INSIDE THE STATOR .2.UNSTEADY PRESSURE ON THE STATOR BLADE SURFACE

The stator flow field of an automotive torque converter is highly unst eady due to potential and viscous interactions with upstream and downs tream rotors. The objective of this investigation is to understand the influence of potential and viscous interactions of the upstream rotor on the stator surface pressure field with a view toward improvement o f the stator design. Five miniature fast-response pressure transducers were embedded on the stator blade. The measurements were conducted at three locations near the leading edge and two locations near the trai ling edge at the midspan location. The upstream flow field was measure d using a fast response five-hole probe and is described in Part I of this paper. The experimental data were processed in the frequency doma in by spectrum analysis and in the temporal-spatial domain by the ense mble-averaging technique. The flow properties were resolved into mean, periodic, aperiodic, and unresolved components. The unsteady amplitud es agreed well with the pressure envelope predicted by panel methods. The aperiodic component was found to be significant due to the rotor-r otor and rotor-stator interactions observed in multistage, multispool environment.