A High-Frequency-Response Pressure Probe for the Measurement of Unsteady Flow Between Two Rotors in a Hydrodynamic Turbomachine

Volume 1: Turbomachinery ◽

10.1115/96-gt-412 ◽

1996 ◽

Author(s):

C. Achtelik ◽

J. Eikelmann

Keyword(s):

Unsteady Flow ◽

Frequency Response ◽

High Frequency ◽

Torque Converter ◽

Pressure Probe ◽

Ensemble Averaging ◽

Probe Diameter ◽

High Frequency Response ◽

Single Sensor ◽

Response Pressure

A new, specially-developed high-frequency-response pressure probe was used to measure the unsteady flow in the interaction region between the pump and the turbine in a hydrodynamic torque converter. In order to reduce the probe diameter, a single-hole, single-sensor cylindrical probe (⌀=1.33mm) was developed, to replace the standard multi-hole probe. The smaller the probe the higher the accuracy in unsteady flow. Therefore this is an improvement over three-hole probe. Three-hole probe measurements were simulated by recording data in three different angular positions. The time variable velocity vectors were determined using the probe’s calibration coefficients and the knowledge of the rotor positions (measured by angle-encoders) for every measurement value. During the data processing, a double ensemble averaging was carried out, taking into account the positions of the pump and the turbine.

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Steady and Unsteady Flow Field at Pump and Turbine Exits of a Torque Converter

Journal of Fluids Engineering ◽

10.1115/1.2820696 ◽

1998 ◽

Vol 120 (3) ◽

pp. 538-548 ◽

Cited By ~ 16

Author(s):

Y. Dong ◽

B. Lakshminarayana ◽

D. Maddock

Keyword(s):

Flow Field ◽

Unsteady Flow ◽

Frequency Response ◽

High Frequency ◽

Free Stream ◽

Torque Converter ◽

Flow Data ◽

High Frequency Response ◽

The Core ◽

Measurement Plane

The steady and unsteady flow field at the pump and the turbine exit of a 245 mm diameter automotive torque converter was measured by a miniature high-frequency-response five-hole probe and a high-frequency-response total pressure Pitot probe in the stationary reference frame. The data were decomposed into blade periodic, blade aperiodic, and unresolved unsteady components. The periodic flow data shows that the pump exit flow has four major zones; the free-stream flow, the blade wake flow, the core-suction corner separation flow, and the mixing zone. The unsteady flow data shows that the unsteadiness in the free-stream is uniform, and the unsteadiness in the wake mixing flow zone is very high. The turbine exit flow is almost fully developed at the measurement plane, the flow field is uniform in the tangential direction, and only radial gradients in flow properties exist. A region of separated flow with high unsteadiness and high axial component of vorticity was observed at the measurement plane near the core.

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

Volume 1: Fora, Parts A and B ◽

10.1115/fedsm2002-31325 ◽

2002 ◽

Author(s):

Y. F. Liu ◽

B. Lakshminarayana

Keyword(s):

Frequency Response ◽

Coriolis Force ◽

High Frequency ◽

Static Pressure ◽

Leading Edge ◽

Torque Converter ◽

Turbine Rotor ◽

High Frequency Response ◽

Pressure Distributions ◽

Turbine Casing

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.

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