The Static Pressure Field on the Casing of the Turbine Rotor in an Automotive Torque Converter Based on High Frequency-Response Rotating Probe Measurement

The static pressure on the rotating turbine casing wall of an automotive torque converter was measured using high frequency-response probe at different speed ratios. The static pressure drop on the turbine rotor casing is the highest compared to the data near the casing wall and the mass averaged value at both the design condition (SR = 0.6) and the peak efficiency condition (SR = 0.8) due to higher centrifugal force effect. The static pressure distributions along the camber line indicate that the blade loading is highest near the turbine mid-chord region at all speed ratios, which can be attributed mainly to the strong Coriolis force due to the strong flow turning both in the meridional direction and on the blade-to-blade surface along the camber line. The normalized static pressure contours indicate that the flow does not separate near the turbine casing (shell). A substantial pressure gradient exists across the passage, which indicates that flow turning and Coriolis force have significant influences. The total unsteadiness is relatively high near the turbine leading edge and low near the turbine trailing edge. The low unsteady level may indicate that the highly viscous fluid employed in the torque converter may have a strong influence on damping the unsteadiness caused by rotor/rotor and rotor/stator interactions.Copyright © 2002 by ASME