Periodic Velocity Measurements in a Wide and Large Radius Ratio Automotive Torque Converter at the Pump∕Turbine Interface

2004 ◽  
Vol 127 (2) ◽  
pp. 308-316 ◽  
Author(s):  
S. O. Kraus ◽  
R. Flack ◽  
A. Habsieger ◽  
G. T. Gillies ◽  
K. Dullenkopf
Keyword(s):  
Flow Field ◽  
Turbine Blade ◽  
Torque Converter ◽  
Operating Conditions ◽  
Radius Ratio ◽  
Small Radius ◽  
Large Radius ◽  
Pump Turbine ◽  
Turbine Inlet ◽  
Significant Difference

The unsteady flow field due to blade passing at the pump∕turbine interface of a torque converter was studied. The current geometry is wide and has a large outer to inner radius ratio. A laser velocimeter was used to measure the periodic velocity components at four operating conditions determined by the speed ratios between the turbine and pump of 0.065 (near stall), 0.600, 0.800, and 0.875 (coupling point). The flow fields at the pump exit and turbine inlet planes were visualized and are presented. Using instantaneous pump and turbine blade positions with the velocity data, animations (“slow-motion movies”) are generated to effectively visualize and understand the unsteady behavior. The turbine inlet flow was markedly periodic due to the exiting jet∕wake from the upstream pump passage; however, the pump exit flow field showed little dependence on the turbine blade positions. The highest unsteadiness was seen for the highest speed ratios. Four “shots” from the sequences of one cycle for all speed ratios and each plane are presented herein. The results are also compared to unsteady results for a previously examined torque converter with a small radius ratio to determine the effect of parametric geometric changes on the flow field. Generally, the unsteady velocity fields show no significant difference for the two geometries—the trends are the same.

Periodic Velocity Measurements in a Wide and Large Radius Ratio Automotive Torque Converter at the Pump/Turbine Interface

2002 ◽  
Author(s):  
S. O. Kraus ◽  
R. Flack ◽  
A. Habsieger ◽  
G. T. Gillies ◽  
K. Dullenkopf
Keyword(s):  
Flow Field ◽  
Turbine Blade ◽  
Torque Converter ◽  
Operating Conditions ◽  
Radius Ratio ◽  
Small Radius ◽  
Large Radius ◽  
Pump Turbine ◽  
Turbine Inlet ◽  
Significant Difference

The unsteady flow field due to blade passing at the pump/turbine interface of a torque converter was studied. The current geometry is wide and has a large outer to inner radius ratio. A laser velocimeter was used to measure the periodic velocity components at four operating conditions determined by the speed ratios between the turbine and pump of 0.065 (near stall), 0.600, 0.800, and 0.875 (coupling point). The flow fields at the pump exit and turbine inlet planes were visualized and are presented. Using instantaneous pump and turbine blade positions with the velocity data, animations (“slow-motion movies”) are generated to effectively visualize and understand the unsteady behavior. The turbine inlet flow was markedly periodic due to the exiting jet/wake from the upstream pump passage; however, the pump exit flow field showed little dependence on the turbine blade positions. The highest unsteadiness was seen for the highest speed ratios. Four “shots” from the sequences of one cycle for all speed ratios and each plane are presented herein. The results are also compared to unsteady results for a previously examined torque converter with a small radius ratio to determine the effect of parametric geometric changes on the flow field. Generally, the unsteady velocity fields show no significant difference for the two geometries — the trends are the same.

scholarly journals Measurements of Strain on 310 mm Torque Converter Turbine Blades

2004 ◽  
Vol 10 (1) ◽  
pp. 55-63
Author(s):  
P. O. Sweger ◽  
C. L. Anderson ◽  
J. R. Blough
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Torque Converter ◽  
Operating Conditions ◽  
Surface Strain ◽  
Speed Ratio ◽  
Constant Input ◽  
Wide Range ◽  
Blade Tip ◽  
Input Torque

An automotive torque converter was tested in order to determine the effect of converter operating condition and turbine blade design on turbine blade strain in the region of the inlet core tab restraint. The converter was operated over a wide range of speed ratios (0 to 0.95) at constant input torque and a stall condition for two input torques. Foil-type strain gages in combination with wireless microwave telemetry were used to measure surface strain on the turbine blade. Strain measurements were made on two turbine blade designs.The steady component of strain over the range of speed ratios suggests the effect of both torque loading and centrifugal loading on the turbine blade tip. The unsteady strain was greatest at stall condition and diminished as speed ratio increased. Greater input torque at stall condition resulted in both greater steady strain and greater unsteady strain. The spectral distribution of strain over the range of tested speed ratios displayed an increase in low-frequency broadband fluctuations near stall condition. A blade-periodic event is observed which correlates to the pump-blade passing frequency relative to the turbine rotating frame. Reducing the blade-tip surface area and increasing the inlet-tab root radius reduced the range of steady strain and magnitude of unsteady strain imposed near the inlet core tab restraint over the range of operating conditions.

Experimental and Numerical Investigation of Stator Exit Flow Field of an Automotive Torque Converter

1996 ◽  
Vol 118 (4) ◽  
pp. 835-843 ◽  
Author(s):  
B. V. Marathe ◽  
B. Lakshminarayana ◽  
Y. Dong
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Numerical Investigation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Torque Converter ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Complex Flow ◽  
Rate Of Decay

The objective of this investigation is to understand the nature of the complex flow field inside each element of the torque converter through a systematic experimental and numerical investigation of the flow field. A miniature five-hole probe was used to acquire the data at the exit of the stator at several operating conditions. The flow field is found to be highly three dimensional with substantial flow deviations, and secondary flow at the exit of the stator. The secondary flow structure, caused by the upstream radial variation of the through flow, induces flow overturning near the core. Flow separation near the shell causes flow underturning in this region. The rate of decay of stator wake is found to be slower than that observed in the wakes of axial flow turbine nozzles. The flow predictions by a Navier–Stokes code are in good agreement with the pressure and the flow field measured at the exit of the stator at the design and the off-design conditions.

Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter: Part II—Unsteady Measurements

1996 ◽  
Vol 118 (3) ◽  
pp. 570-577 ◽  
Author(s):  
K. Brun ◽  
R. D. Flack ◽  
J. K. Gruver
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Incidence Angle ◽  
Angular Position ◽  
Three Dimensional ◽  
Torque Converter ◽  
Operating Conditions ◽  
Plane Flow ◽  
Periodic Fluctuations ◽  
Pump Inlet

The unsteady velocity field found in the pump of an automotive torque converter was measured using laser velocimetry. Velocities in the inlet, mid-, and exit planes of the pump were investigated at two significantly different operating conditions: turbine/pump rotational speed ratios of 0.065 and 0.800. A data organization method was developed to visualize the three-dimensional, periodic unsteady velocity field in the rotating frame. For this method, the acquired data are assumed to be periodic at synchronous and blade interaction frequencies. Two shaft encoders were employed to obtain the instantaneous angular position of the torque converter pump and turbine at the instant of laser velocimeter data acquisition. By proper “registration” of the data, visualizing the transient interaction effects between the stator and the pump, and between the pump and the turbine, was possible. Results showed strong cyclic velocity fluctuations in the pump inlet plane as a function of the relative stator-pump position. Typical percent periodic fluctuations in the through flow velocity were 70 percent of the average throughflow velocity. The upstream propagation influence of the turbine on the pump exit plane flow field was seen to be smaller. Percent periodic fluctuations of the throughflow velocity were typically 30 percent. The effect of the stator and turbine on the midplane flow field was seen to be negligible. The incidence angle at the pump inlet fluctuated by 27 and 14 deg for the 0.065 and 0.800 speed ratios, respectively. Typical slip factors at the exit were 0.965 and fluctuated by less than 1 percent.

scholarly journals Experimental research on flow field of a high head model pump turbine based on PIV test

2020 ◽  
Author(s):  
Demin Liu ◽  
Yongzhi Zhao ◽  
Weilin Xu
Keyword(s):  
Flow Field ◽  
Pressure Pulsation ◽  
Internal Flow ◽  
Operating Conditions ◽  
Head Model ◽  
Test Technique ◽  
Pump Turbine ◽  
Flow Angle ◽  
Operating Condition ◽  
Cavitation Pressure

Abstract Pump turbine operating conditions are complex, mainly including turbine mode and pump mode. Pump turbines have various instability problems during operation, such as S-shaped, pump hump, pressure pulsation and cavitation. PIV (Particle Image Velocimetry) is a very effective test technique for the internal flow field observation of pump turbines. In this paper, the internal flow field of pump hump, cavitation, pressure pulsation and four quadrants of the pump turbine are tested by PIV technology. The experimental observations show that the internal flow on those unstable working conditions of the pump turbine is extremely complicated. Those conditions which the vortex separation is serious and the flow angle is changed is far away the best efficiency working condition. Since the operating condition deviates from the optimal operating condition, the inflow Angle is changed and the inflow Angle is far away from the optimal inflow Angle.And the vortex induces and develops strongly by PIV test. The flow phenomenon are demonstrated at each operating points by PIV test.

Experimental and Numerical Investigation of Stator Exit Flow Field of an Automotive Torque Converter

1994 ◽  
Author(s):  
B. V. Marathe ◽  
B. Lakshminarayana ◽  
Y. Dong
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Numerical Investigation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Torque Converter ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Complex Flow ◽  
Rate Of Decay

The objective of this investigation is to understand the nature of the complex flow field inside each element of the torque converter through a systematic experimental and numerical investigation of the flow field. A miniature five-hole probe was used to acquire the data at the exit of the stat or at several operating conditions. The flow field is found to be highly three-dimensional with substantial flow deviations, and secondary flow at the exit of the stator. The secondary flow structure, caused by the upstream radial variation of the through flow, induces flow overturning near the core. Flow separation near the shell causes flow underturning in this region. The rate of decay of stator wake is found to be slower than that observed in the wakes of axial flow turbine nozzles. The flow predictions by a Navier-Stokes code are in good agreement with the pressure and the flow field measured at the exit of the stator at the design and the off-design conditions.

scholarly journals Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter: Part II — Unsteady Measurements

1994 ◽  
Author(s):  
K. Brun ◽  
R. D. Flack ◽  
J. K. Gruver
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Flow Velocity ◽  
Angular Position ◽  
Torque Converter ◽  
Operating Conditions ◽  
Plane Flow ◽  
Through Flow ◽  
Periodic Fluctuations ◽  
Pump Inlet

The unsteady velocity field found in the pump of an automotive torque converter was measured using laser velocimetry. Velocities in the inlet, mid-, and exit planes of the pump were investigated at two significantly different operating conditions: turbine/pump rotational speed ratios of 0.065, and 0.800. A data organization method was developed to visualize the three dimensional, periodic unsteady velocity field in the rotating frame. For this method, the acquired data is assumed to be periodic at synchronous and blade interaction frequencies. Two shaft encoders were employed to obtain the instantaneous angular position of the torque converter pump and turbine at the instant of laser velocimeter data acquisition. By proper “registration” of the data visualizing the transient interaction effects between the stator and the pump, and the pump and the turbine was possible. Results showed strong cyclic velocity fluctuations in the pump inlet plane as a function of the relative stator-pump position. Typical percent periodic fluctuations in the through flow velocity were 70% of the average through flow velocity. The upstream propagation influence of the turbine on the pump exit plane flow field was seen to he smaller. Percent periodic fluctuations of the through flow velocity were typically 30%. The effect of the stator and turbine on the mid-plane flow field was seen to be negligible. The incidence angle at the pump inlet fluctuated by 27° and 14° for the 0.065 and 0.800 speed ratios, respectively. Typical slip factors at the exit were 0.965 and fluctuated by less than 1%.

Non-Steady Flow Measurements Inside a Hydrodynamic Torque Converter by Hot-Film Anemometry

1992 ◽  
Author(s):  
V. Browarzik ◽  
K. G. Grahl
Keyword(s):  
Flow Field ◽  
Steady Flow ◽  
Torque Converter ◽  
Operating Conditions ◽  
Measuring System ◽  
Pump Impeller ◽  
Flow Measurements ◽  
First Results ◽  
Hot Film ◽  
Hot Film Anemometry

The overall-characteristics of hydrodynamic torque converters have been discussed often, although there is little knowledge about the flow field inside the circuit. During former investigations at our institute flow measurements have been made and a CFD-program was developed to calculate the flow through the guide vanes and the pump impeller. Our present studies now examine the non-steady flow field at the inlet and outlet of the pump and the turbine impeller by means of hot-film anemometry and a computer based measuring system. The measuring techniques have been developed and now measurements are made at different operating points. Later the measurements will be performed with special regard to non-steady changes of operating conditions. The paper describes the test facilities, the measuring equipment and the techniques used to evaluate the measured data. First results of test measurements are presented.

The Interaction of Purge Flows With Secondary Flow Features in Turbine Center Frames

2021 ◽  
Author(s):  
Marios Patinios ◽  
Filippo Merli ◽  
Asim Hafizovic ◽  
Emil Göttlich
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Total Pressure ◽  
Operating Conditions ◽  
Large Radius ◽  
Plane Flow ◽  
Subsequent Performance ◽  
Performance Reduction ◽  
Viscous Shear ◽  
Flow Features

Abstract The turbine center frame (TCF) is an inherent component of modern turbofan aircraft engines, used for facilitating the large radius change between the high-pressure (HPT) and low-pressure (LPT) turbines. Secondary flow features that develop in the TCF result in total pressure loss of the mainstream flow and a subsequent performance reduction for the whole of the engine. Purge flows from the HPT interact with these flow features affecting their development and strength. Understanding the details of this interaction is therefore of paramount importance for the design of more efficient engines of the future. This paper presents a detailed investigation of the interaction of purge flows from the hub and shroud cavities upstream and downstream of the HPT rotor with the secondary flow features in a TCF. The investigation was conducted using aerodynamic and seed gas concentration measurements in an engine-representative HPT-TCF setup and under engine-realistic operating conditions. The upstream purge flows interact with the flow-field of the rotor, and especially with the upper and lower passage vortices where they are mainly entrained, forming “zones-of-influence” that occupy the upper and lower 35% of the span at the TCF inlet. Dilution of these purge flows occurs through vortex-to-vortex interactions and in-plane flow migrations driven by the vortices. At the outlet of the TCF, the upstream purge flows form effectiveness bands that encapsulate the various counter-rotating vortices near the hub and shroud. This indicates that these counter-rotating vortices were formed at the inlet of the TCF, in a flow that already includes the upstream purge flows. The downstream purge flows exit the hub and shroud cavities forming effectiveness boundary layers at the inlet of the TCF of thickness equal to around 15% of the span. The circumferential distribution of these purge flows is however asymmetric, owing to the also asymmetric static pressure distribution at the inlet of the TCF, as a result of the effect of the propagated flow-field of the stator vanes. At the outlet of the TCF, the distribution of the downstream hub purge appears as distinct effectiveness lobes with the same periodicity as the HPT vanes. The formation of the lobes is as a result of intense interaction between the counter-rotating vortex pairs and the downstream hub purge flow. The viscous shear mixing due to this interaction is also the cause for the low total pressure in the regions influenced by the lobes. The distribution of the downstream shroud purge appears as alternating regions of high and low effectiveness as a result of radially inwards and outwards flow migrations caused by the shearing actions of the counter rotating vortices near the shroud. These migrations are the cause of regions with the lowest total pressure at the outlet of the TCF.

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

1999 ◽  
Vol 5 (2) ◽  
pp. 99-116 ◽  
Author(s):  
B. V. Marathe ◽  
B. Lakshminarayana
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Torque Converter ◽  
Frame Of Reference ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Speed Ratio ◽  
Secondary Vortex ◽  
Flow Properties ◽  
Periodic Components

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.

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