Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter: Part I—Average Measurements

1996 ◽  
Vol 118 (3) ◽  
pp. 562-569 ◽  
Author(s):  
J. K. Gruver ◽  
R. D. Flack ◽  
K. Brun
Keyword(s):  
Angular Position ◽  
Torque Converter ◽  
Secondary Flows ◽  
Speed Ratio ◽  
Exit Plane ◽  
Centrifugal Pumps ◽  
Torque Distribution ◽  
Average Flow Velocity ◽  
Pump Shaft ◽  
Pump Inlet

A torque converter was tested for two turbine/pump rotational speed ratios, 0.065 and 0.800, and a laser velocimeter was used to measure three components of velocity within the pump. Shaft encoders were used to record the instantaneous pump angular position, which was correlated with the velocities. Average flow velocity profiles were obtained for the pump inlet, mid-, and exit planes. Large separation regions were seen in the mid- and exit planes of the pump for a speed ratio of 0.800. Strong counterclockwise secondary flows were observed in the midplane and strong clockwise secondary flows were seen in the exit plane of the pump for all conditions; vorticities were evaluated and are reported. Velocity data were also used to find the torque distribution. For both speed ratios the torque was approximately evenly distributed between the inlet and exit. Finally, slip factors were evaluated at the mid-and exit planes. At the midplane they were approximately the same as for conventional centrifugal pumps; however, at the exit plane the slip factors are larger than for centrifugal pumps.

Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter: Part I — Average Measurements

1994 ◽  
Author(s):  
J. K. Gruver ◽  
R. D. Flack ◽  
K. Brun
Keyword(s):  
Angular Position ◽  
Torque Converter ◽  
Secondary Flows ◽  
Speed Ratio ◽  
Exit Plane ◽  
Centrifugal Pumps ◽  
Torque Distribution ◽  
Average Flow Velocity ◽  
Pump Shaft ◽  
Pump Inlet

A torque converter was tested for two turbine/pump rotational speed ratios, 0.065, and 0.800, and a laser velocimeter was used to measure three components of velocity within the pump. Shaft encoders were used to record the instantaneous pump angular position, which was correlated with the velocities. Average flow velocity profiles were obtained for the pump inlet, mid-, and exit planes. Large separation regions were seen in the mid- and exit planes of the pump for a speed ratio of 0.800. Strong counter-clockwise secondary flows were observed in the mid-plane and strong clockwise secondary flows were seen in the exit plane of the pump for all conditions; vorticities were evaluated and are reported. Velocity data was also used to find the torque distribution. For both speed ratios the torque was approximately evenly distributed between the inlet and exit. Finally, slip factors were evaluated at the mid- and exit planes. At the mid-plane they were approximately the same as for conventional centrifugal pumps; however, at the exit plane the slip factors are larger than for centrifugal pumps.

scholarly journals Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter Part I – Effect of Speed Ratio

2000 ◽  
Vol 6 (3) ◽  
pp. 167-180 ◽  
Author(s):  
Steven B. Ainley ◽  
Ronald D. Flack ◽  
Klaus Brun ◽  
Tony J. Rovello
Keyword(s):  
Flow Field ◽  
Rotational Speed ◽  
Angular Position ◽  
Torque Converter ◽  
Speed Ratio ◽  
Exit Plane ◽  
Centrifugal Pumps ◽  
Plane Flow ◽  
Shaft Encoder ◽  
Mass Flows

A torque converter was tested at four turbine/pump rotational speed ratios (0.200, 0.400, 0.600, and 0.800) all with a constant pump rotational speed in order to determine the effect of speed ratio on the torque converter pump flow field. Laser velocimetry was used to measure three components of velocity within the pump and a shaft encoder was employed to record the instantaneous pump angular position. Shaft encoder information was correlated with measured velocities to develop flow field blade-to-blade profiles and vector plots. Measurements were obtained in both the pump mid- and exit planes for all four speed ratios. Results showed large separation regions and jet/wake flows throughout the pump. The midplane flow was found to have strong counter-clockwise secondary components and the exit plane flow had strong clockwise secondary components. Mass flows were calculated from the velocity data and were found to decrease as the speed ratio was increased. Also, the vorticity and slip factors were calculated from the experimental data and are included. The mid-plane slip factors compare favorably to those for conventional centrifugal pumps but less slip was present in the exit plane than the mid-plane. Neither the slip factor nor the vorticity were seen to be strongly affected by the speed ratio. Finally, the torque core-to-shell and blade-to-blade torque distributions are presented for both planes.

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

1997 ◽  
Vol 119 (3) ◽  
pp. 655-662 ◽  
Author(s):  
K. Brun ◽  
R. D. Flack
Keyword(s):  
Velocity Field ◽  
Turbine Blades ◽  
Angular Position ◽  
Torque Converter ◽  
Speed Ratio ◽  
Velocity Data ◽  
Velocity Fluctuations ◽  
Blade Passage ◽  
Turbine Pump ◽  
Output Torque

The unsteady velocity field found in the turbine of an automotive torque converter was measured using laser velocimetry. Velocities in the inlet, quarter, mild, and exit planes of the turbine were investigated at two significantly different turbine/pump rotational speed ratios: 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 velocity data, visualizing the transient interaction effects between the turbine, pump, and stator was possible. Results showed strong cyclic velocity fluctuations in the turbine inlet plane as a function of the relative turbine-pump position. These fluctuations are due to the passing of upstream pump blades by the slower rotating turbine blades. Typical fluctuations in the through flow velocity were 3.6 m/s. Quarter and midplane velocity fluctuations were seen to be lower; typical values were 1.5 m/s and 0.8 m/s, respectively. The flow field in the turbine exit plane was seen to be relatively steady with negligible fluctuations of less than 0.03 m/s. From the velocity data, the fluctuations of turbine performance parameters such as flow inlet angles, root-mean-square unsteadiness, and output torque per blade passage were calculated. Incidence angles were seen to vary by 3 and 6 deg for the 0.800 and 0.065 speed ratios, respectively, while the exit angles remained steady. The turbine output torque per blade passage fluctuated by 0.05 Nm for the 0.800 speed ratio and 0.13 Nm for the 0.065 speed ratio.

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 Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter Part II – Effect of Pump Speed and Oil Viscosity

2000 ◽  
Vol 6 (3) ◽  
pp. 181-190 ◽  
Author(s):  
Ronald D. Flack ◽  
Steven B. Ainley ◽  
Klaus Brun ◽  
Leonard Whitehead
Keyword(s):  
Rotational Speed ◽  
Three Dimensional ◽  
Torque Converter ◽  
Secondary Flows ◽  
Working Fluid ◽  
Speed Ratio ◽  
Oil Viscosity ◽  
Low Velocity ◽  
Pump Speed ◽  
Mass Flows

The velocity field inside a torque converter pump was studied for two separate effects: variable pump rotational speed and variable oil viscosity. Three-dimensional velocity measurements were taken using a laser velocimeter for both the pump mid- and exit planes. The effect ofvariable pump rotational speed was studied by running the pump at two different speeds and holding speed ratio (pump rotational speed]turbine rotational speed) constant. Similarly, the effect of viscosity on the pump flow field was studied by varying the temperature and]or using two different viscosity oils as the working fluid in the pump. Threedimensional velocity vector plots, through-flow contour plots, and secondary flow profiles were obtained for both pump planes and all test conditions. Results showed that torque converter mass flows increased approximately linearly with increasing pump rotational speed (and fixed speed ratio) but that the flow was not directly proportional to pump rotational speed. However, mass flows were seen to decrease as the oil viscosity was decreased with a resulting increased Reynolds number; for these conditions the high velocity regions were seen to decrease in size and low velocity regions were seen to increase in size. In the pump mid-plane strong counter-clockwise secondary flows and in the exit plane strong clockwise secondary flows were observed. The vorticities and slip factors were calculated from the experimental results and are presented. The torque core-to-shell and blade-to-blade torque distributions were calculated for both planes. Finally, the flow fields were seen to demonstrate similitude when Reynolds numbers were matched.

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

1995 ◽  
Author(s):  
Klaus Bran ◽  
Ronald D. Flack
Keyword(s):  
Velocity Field ◽  
Angular Position ◽  
Torque Converter ◽  
Operating Conditions ◽  
Speed Ratio ◽  
Velocity Data ◽  
Velocity Fluctuations ◽  
Blade Passage ◽  
Turbine Pump ◽  
Output Torque

The unsteady velocity field found in the turbine of an automotive torque converter was measured using laser velocimetry. Velocities in the inlet, quarter, mid, and exit planes of the turbine 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 velocity data, visualizing the transient interaction effects between the turbine, pump, and stator was possible. Results showed strong cyclic velocity fluctuations in the turbine inlet plane as a function of the relative turbine-pump position. These fluctuations are due to the passing of upstream pump blades by the slower rotating turbine blades. Typical fluctuations in the through flow velocity were 3.6 m/s. Quarter and mid plane velocity fluctuations were seen to be lower; typical values were 1.5 m/s and 0.8 m/s, respectively. The flow field in the turbine exit plane was seen to be relatively steady with negligible fluctuations of less than 0.03 m/s. From the velocity data, the fluctuations of turbine performance parameters such as flow inlet angles, root-mean-square unsteadiness, and output torque per blade passage were calculated. Incidence angles were seen to vary by 3° and 6° for the 0.800 and 0.065 speed ratios, respectively, while the exit angles remained steady. The turbine output torque per blade passage fluctuated by 0.05 Nm for the 0.800 speed ratio and 0.13 Nm for the 0.065 speed ratio.

Perspective: Fluid Dynamics and Performance of Automotive Torque Converters: An Assessment

1996 ◽  
Vol 118 (4) ◽  
pp. 665-676 ◽  
Author(s):  
T. W. von Backstro¨m ◽  
B. Lakshminarayana
Keyword(s):  
Measurement Techniques ◽  
Torque Converter ◽  
Fast Response ◽  
Secondary Flows ◽  
Experimental Investigations ◽  
Meridional Plane ◽  
Suction Surface ◽  
Pressure Surface ◽  
Torque Converters ◽  
Pump Inlet

Experimental investigations by various groups over the past decade have uncovered the main features of the flow in hydraulic torque converters. Measurement techniques include laser and hot wire velocimetry, fast response and conventional five-hole probes, and blade and wall static pressure measurement. In both the pump and turbine, the through flow velocity is high near the pressure surface shell corner while the flow in the suction surface core corner is highly turbulent and may be separated and reversed. The position of the stator in a passage curved in the meridional plane leads to secondary flow and low velocities at the core near the pump inlet. Velocity gradients coupled with flow turning and rotor rotation lead to strong secondary flows. By using data from a combination of measurement techniques, torque converter torque, power and efficiency are calculated, and the effect of element efficiency on overall efficiency is demonstrated. It is concluded that design methods should be developed that allow for nonuniform velocity profiles, flow separation, secondary circulation and interaction effects between elements.

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%.

Effect of Rotational Speed on the Average Flow Field at the Pump/Turbine Interface of an Automotive Torque Converter

2001 ◽  
Author(s):  
M. Hotho ◽  
M. R. Gruber ◽  
R. D. Flack ◽  
G. T. Gillies
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
Leading Edge ◽  
Torque Converter ◽  
Flow Fields ◽  
Speed Ratio ◽  
Exit Plane ◽  
Pump Turbine ◽  
Plane Flow ◽  
The Core

Abstract The internal flow fields of a pump/turbine interface in a torque converter were examined using laser velocimetry. The torque converter was operated at three different turbine/pump rotational speed ratios: 0.065 (near stall), 0.600, and 0.800 (near coupling point) and for each speed ratio three different pump and turbine speeds were used. Most importantly, the dimensional rotational speed had minimal effects on the flow fields — flow characteristics were Reynolds number independent. At the pump exit plane the flow is non-uniform in the blade-to-blade direction at all speed ratios and speeds. Velocities were fairly uniform in the core-to-shell direction. Through flow velocity non-uniformity became more pronounced as the speed ratio increased. The pump exit plane slip factors are near unity. At high speed ratios the flow in the turbine inlet plane flow is non-uniform in the blade-to-blade direction. Also at high speed ratios, velocities are fairly uniform in the core-to-shell direction but high velocities move near the shell at lower speed ratios. The turbine leading edge incidence angles were found to depend strongly on the speed ratio, ranging from positive to negative.

Second Vane Total Pressure Loss Due to Endwall Iceform Contouring

2008 ◽  
Author(s):  
Ronald S. LaFleur
Keyword(s):  
Heat Transfer ◽  
Secondary Flow ◽  
Pressure Loss ◽  
Total Pressure ◽  
Aerodynamic Drag ◽  
Pressure Coefficient ◽  
Secondary Flows ◽  
Total Pressure Loss ◽  
Surface Shape ◽  
Exit Plane

The iceformation design method generates an endwall contour, altering the secondary flows that produce elevated endwall heat transfer load and total pressure losses. Iceformation is an analog to regions of metal melting where a hot fluid alters the isothermal surface shape of a part as it is maintained by a cooling fluid. The passage flow, heat transfer and geometry evolve together under the constraints of flow and thermal boundary conditions. The iceformation concept is not media dependent and can be used in analogous flows and materials to evolve novel boundary shapes. In the past, this method has been shown to reduce aerodynamic drag and total pressure loss in flows such as diffusers and cylinder/endwall junctures. A prior paper [1] showed that the Reynolds number matched iceform geometry had a 24% lower average endwall heat transfer than the rotationally symmetric endwall geometry of the Energy Efficiency Engine (E3). Comparisons were made between three endwall geometries: the ‘iceform’, the ‘E3’ and the ‘flat’ as a limiting case of the endwall design space. This paper adds to the iceformation design record by reporting the endwall aerodynamic performances. Second vane exit flow velocities and pressures were measured using an automated 2-D traverse of a 1.2 mm diameter five-hole probe. Exit plane maps for the three endwall geometries are presented showing the details of the total pressure coefficient contours and the velocity vectors. The formation of secondary flow vortices is shown in the exit plane and this results in an impact on exit plane total pressure loss distribution, off-design over- and under-turning of the exit flow. The exit plane contours are integrated to form overall measures of the total pressure loss. Relative to the E3 endwall, the iceform endwall has a slightly higher total pressure loss attributed to higher dissipation of the secondary flow within the passage. The iceform endwall has a closer-to-design exit flow pattern than the E3 endwall.

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