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Research Papers: Gas Turbines: Oil and Gas Applications

Assessment of the Oil Scoop Capture Efficiency in High Speed Rotors

[+] Author and Article Information
Paloma Paleo Cageao

Faculty of Engineering,
Gas Turbine and Transmissions Research
Centre,
University of Nottingham,
Nottingham NG8 1BB, UK
e-mail: Paloma.Paleo@nottingham.ac.uk

Kathy Simmons

Faculty of Engineering,
Gas Turbine and Transmissions Research
Centre,
University of Nottingham,
Nottingham NG8 1BB, UK
e-mail: kathy.simmons@nottingham.ac.uk

Arun Prabhakar

Faculty of Engineering,
Gas Turbine and Transmissions Research
Centre,
University of Nottingham,
Nottingham NG8 1BB, UK
e-mail: arun.prabhakar@nottingham.ac.uk

Budi Chandra

University of West England,
Bristol BS16 1QY, UK
e-mail: budi.chandra@uwe.ac.uk

1Corresponding author.

Contributed by the Oil and Gas Applications Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received May 12, 2017; final manuscript received September 21, 2017; published online October 29, 2018. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 141(1), 012401 (Oct 29, 2018) (12 pages) Paper No: GTP-17-1167; doi: 10.1115/1.4040812 History: Received May 12, 2017; Revised September 21, 2017

Experimental research was conducted into a scooped rotor system that captures oil from a stationary jet and directs it through passages within the shaft to another axial location. Such a system has benefits for delivering oil via under-race feed to aeroengine bearings where direct access is limited. Oil capture efficiency was calculated for three jet configurations, a range of geometric variations relative to a baseline and a range of operating conditions. Flow visualization techniques yielded high-speed imaging in the vicinity of the scoop leading edge. Overall capture efficiency depends on the amount of oil initially captured by the scoop that is retained. Observation shows that when the jet hits the tip of a scoop element, it is sliced and deflected upward in a “plume.” Ligaments and drops formed from this plume are not captured. In addition, some oil initially captured is flung outward as a consequence of centrifugal force. Although in principle capture of the entire supply is possible over most of the shaft speed range, as demonstrated by a simplified geometric model, in practice 60–70% is typical. Significant improvement in capture efficiency was obtained with a lower jet angle (more radial) compared to baseline. Higher capture efficiencies were found where the ratio of jet to scoop tip speed was lower. This research confirms the capability of a scoop system to capture and retain delivered oil. Additional numerical and experimental work is recommended to further optimize the geometry and increase the investigated temperature and pressure ranges.

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References

Zaretsky, E. V. , 1997, “ Rolling Bearing and Gear Lubrication,” Tribology for Aerospace Applications, Society of Tribologists and Lubrication Engineers, Park Ridge, IL, pp. 207–323.
Brown, P. F. , 1970, “ Bearings and Dampers for Advanced Jet Engines,” SAE Paper No. 700318.
Lee, C. W. , Johnson, G. R. , Palma, P. C. , Simmons, K. , and Pickering, S. J. , 2004, “ Factors Affecting the Behaviour and Efficiency of a Targeted Jet Delivering Oil to a Bearing Lubrication System,” ASME Paper No. GT2004-53606.
Kovaleski, S. , 1987, “ Radial Scoop Construction,” Farmington, CT, U.S. Patent No. 4,648,485. https://patents.google.com/patent/US4648485A/fr
Fisher, K. , Demel, H. , and Hazeley, R. , 2002, “ Methods and Apparatus for Supplying Oil to Bearing Assemblies,” U.S. Patent No. 6,409,464.
Fisher, K. , 2004, “ Bi-Directional Oil Scoop for Bearing Lubrication,” General Electric Co, Boston, MA, U.S. Patent No. 6,682,222. https://patents.google.com/patent/US6682222
Dins, J. , Hogan, J. , and Kumar, A. , 2007, “ Curved Blade Oil Scoop,” Honeywell International Inc., Morris Plains, NJ, U.S. Patent No. 7,244,096. https://patents.google.com/patent/US7244096
Mcdonagh, S. , 2016, “ A Liquid-Capturing Shaft,” U.S. Patent No. 2016/0069186 A1.
Prasad, S. K. , Sangli, P. , Buyukisik, O. , and Pugh, D. , 2014, “ Prediction of Gas Turbine Oil Scoop Capture Efficiency,” ASME Paper No. GTINDIA2014-8329.
Korsukova, E. , Kruisbrink, A. , Morvan, H. , Cageao, P. P. , and Simmons, K. , 2016, “ Oil Scoop Simulation and Analysis Using CFD and SPH,” ASME Paper No. GT2016-57554.
Kruisbrink, A. , Korsukova, E. , Evans, K. , and Morvan, H. P. , 2017, “ SILOET 2 Project 18.4: CFD and SPH Work on the Compound Scoop,” Gas Turbine and Transmissions Research Centre, University of Nottingham, Nottingham, UK, Internal Report No. FF142/AK/03.

Figures

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Fig. 3

Front view of scoop system (illustrative geometry)

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Fig. 2

Side view of scoop system (illustrative geometry)

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Fig. 1

Oil jet targeted directly at bearing (a) shows oil targeted directly at a bearing but (b) shows under-race feed

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Fig. 4

Capture criterion. (a) At VR<VRthr, the oil jet passes point B before next scoop reaches there. The oil jet is not entirely captured. (b) At VR≥VRthr, the scoop passes point B before the oil jet. The oil jet is entirely captured.

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Fig. 5

Schematic illustration of the single shaft test facility with scoop module mounted

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Fig. 6

Schematic illustration of the oil scoop module and associated hydraulic circuit

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Fig. 7

Oil scoop test module: side view (left) and front view (right). 1—front chamber, 2—scoop chamber, 3—oil jet injector, 4—front chamber exit, and 5—scoop chamber drain.

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Fig. 14

Variation in capture efficiency with velocity ratio for a fixed jet velocity and varying shaft speed

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Fig. 8

Repeat test indicating level of repeatability. Test configuration: Tandem jet, dc*= 1 and θjet=θref−5.

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Fig. 9

(a) Visualization setup. 6—borescope, 7—camera, and 8—lights. (b) Direction and field of view of the borescope.

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Fig. 10

Images of the scoop device and the oil jet injector. Top: The ROI is marked with a rectangle. Bottom: Frame showing the ROI from the recorded high speed filming using the borescope connected to the high speed camera.

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Fig. 11

Geometrically simplified scoop test module. Highlighted are the wedge shape and the thin wire.

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Fig. 12

Jet configurations tested: (a) twin jets, (b) tandem jets, and (c) single jet

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Fig. 13

Baseline oil jet orientation, θref. Arrow defines the positive direction of the angle.

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Fig. 15

Visualization of the jet flow at increments of 1×10−3 s with single jet for a simplified geometry of the scoop device. Angle jet is θref, scoop construction ratio of 1 at the shaft speed ratio of 0.05 and VR of 4.3.

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Fig. 16

Visualization of the jet flow evolution at increments of 2×10−3 s for a twin jet configuration. Angle jet is θref, scoop constriction ratio of 1 at shaft speed ratio of 0.05 and VR of 4.3. The arrow points to the leading edge of the scoop.

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Fig. 17

Effect of constriction on capture efficiency for fixed jet velocity and varying shaft speed

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Fig. 18

Graph showing how capture efficiency varies with shaft speed for three constriction values. Velocity ratios as plotted in the chart.

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Fig. 19

Capture efficiency as a function of shaft speed for three constriction values and velocity ratios as indicated in the chart

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Fig. 20

Graph showing the effect of jet configuration for a case with 2 mm constriction and velocity ratios as shown in Fig. 18

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Fig. 21

Visualization of the jet flow behavior at the shaft speed ratio of 0.1 for three different jet configurations: (a) single jet, (b) twin jet, and (c) tandem jet

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Fig. 22

Visualization of the jet flow behavior at the shaft speed ratio of 0.8 for three different jet configurations: (a) single jet, (b) twin jet, and (c) tandem jet

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Fig. 23

Effect of jet angle on capture efficiency for three scoop constrictions for the tandem jet configuration

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Fig. 24

Position where oil jet impacts on the scoop at different angles. Scoop operating with VR≥VRthr (a) at the baseline jet angle θref (upper line) and at a jet angle lower than the baseline, θjet<θref (lower line). (b) Key zones of the simplified scoop geometry.

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Fig. 25

Comparison of oil deflected after hitting the edge of the scoops for the tandem jet configuration and two jet angles: (a) Baseline jet angle θref and (b) θref−5 deg jet angle. The evolution of the jet flow is shown 1×10−3 s before the jet hits the edge of the scoop, during the slicing action at ti and 3×10−3 s after hitting the edge of the scoop. Images for shaft speed ratio 0.05, VR 4.3, and constriction ratio 1. The arrow points to the leading edge of the scoop.

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