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Research Papers: Flows in Complex Systems

Three-Dimensional Numerical Simulation of an External Gear Pump With Decompression Slot and Meshing Contact Point

[+] Author and Article Information
R. Castilla

LABSON,
Department of Fluid Mechanics,
Universitat Politècnica de Catalunya,
Terrassa, Barcelona 08222, Spain
e-mail: castilla@mf.upc.edu

P. J. Gamez-Montero

LABSON,
Department of Fluid Mechanics,
Universitat Politècnica de Catalunya,
Terrassa, Barcelona 08222, Spain
e-mail: pjgm@mf.upc.edu

D. del Campo

Department of Aeronautics,
Universitat Politècnica de Catalunya,
Terrassa, Barcelona 08222, Spain
e-mail: david.del.campo@upc.edu

G. Raush

LABSON,
Department of Fluid Mechanics,
Universitat Politècnica de Catalunya,
Terrassa, Barcelona 08222, Spain
e-mail: gustavo.raush@upc.edu

M. Garcia-Vilchez

LABSON,
Department of Fluid Mechanics,
Universitat Politècnica de Catalunya,
Terrassa, Barcelona 08222, Spain
e-mail: mercedes.garcia-vilchez@upc.edu

E. Codina

LABSON,
Department of Fluid Mechanics,
Universitat Politècnica de Catalunya,
Terrassa, Barcelona 08222, Spain
e-mail: ecodina@mf.upc.edu

1Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received April 10, 2014; final manuscript received November 12, 2014; published online January 13, 2015. Assoc. Editor: Bart van Esch.

J. Fluids Eng 137(4), 041105 (Apr 01, 2015) (10 pages) Paper No: FE-14-1184; doi: 10.1115/1.4029223 History: Received April 10, 2014; Revised November 12, 2014; Online January 13, 2015

Recently several works have been published on numerical simulation of an external gear pump (EGP). Such kinds of pumps are simple and relatively inexpensive, and are frequently used in fluid power applications, such as fluid power in aeronautical, mechanical, and civil engineering. Nevertheless, considerable effort is being undertaken to improve efficiency and reduce noise and vibration produced by the flow and pressure pulsations. Numerical simulation of an EGP is not straightforward principally for two main reasons. First, the gearing mechanism between gears makes it difficult to handle a dynamic mesh without a considerable deterioration of mesh quality. Second, the dynamic metal–metal contact simulation is important when high pressure outflow has to be reproduced. The numerical studies published so far are based on a two-dimensional (2D) approximation. The aim of the present work is to contribute to the understanding of the fluid flow inside an EGP by means of a complete three-dimensional (3D) parallel simulation on a cluster. The 3D flow is simulated in a linux cluster with a solver developed with the openfoam Toolbox. The hexahedral mesh quality is maintained by periodically replacing the mesh and interpolating the physical magnitudes fields. The meshing contact point is simulated with the viscous wall approach, using a viscosity model based on wall proximity. The results for the flow rate ripples show a similar behavior to that obtained with 2D simulations. However, the flow presents important differences inside the suction and the discharge chambers, principally in the regions of the pipes' connection. Moreover, the decompression slot below the gearing zone, which can not be simulated with a 2D approximation, enables a more realistic simulation of a contact ratio greater than 1. The results are compared with experimental measurements recently published.

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References

Bruce, D., Wilson, M., and Generalis, S., 1997, “Flow Field Analysis of Both the Trilobal Element and Mixing Disc Zones Within a Closely Intermeshing, Co-Rotating Twin-Screw Extruder,” Int. Polym. Process., 12(4), pp. 323–330. [CrossRef]
Voorde, J. V., Vierendeels, J., and Dick, E., 2004, “Development of a Laplacian-Based Mesh Generator for ALE Calculations in Rotary Volumetric Pumps and Compressors,” Comput. Methods Appl. Mech. Eng., 193(39–41), pp. 4401–4415. [CrossRef]
Ivantysyn, J., and Ivantysynova, M., 2001, Hydrostatic Pumps and Motors, Akademia Books International, New Delhi, India.
Eaton, M., Keogh, P. S., and Edge, K. A., 2006, “The Modeling, Prediction, and Experimental Evaluation of Gear Pump Meshing Pressures With Particular Reference to Aero-Engine Fuel Pumps,” Proc. Inst. Mech. Eng., Part I, 220(15), pp. 365–379 [CrossRef].
Borghi, M., Milani, M., Paltrinieri, F., and Zardin, B., 2005, “Pressure Transients in External Gear Pumps and Motors Meshing Volumes,” SAE Technical Paper No. 2005-01-3619.
Wang, S., Sakurai, H., and Kasarekar, A., 2011, “The Optimal Design in External Gear Pumps and Motors,” IEEE/ASME Trans. Mechatronics, 16(5), pp. 945–952. [CrossRef]
Ohta, H., Kurita, M., and Kishi, K., 2014, “Effects of Contact Ratio on Transmission Errors of Trochoidal Gears,” ASME J. Tribol., 136(3), p. 031101. [CrossRef]
Manring, N. D., and Kasaragadda, S. B., 2003, “The Theoretical Flow Ripple of an External Gear Pump,” ASME J. Dyn. Syst., Meas., Control, 125(3), pp. 396–404. [CrossRef]
Strasser, W., 2007, “CFD Investigation of Gear Pump Mixing Using Deforming/Agglomerating Mesh,” ASME J. Fluids Eng., 129(4), pp. 476–484. [CrossRef]
Castilla, R., Gamez-Montero, P., Ertürk, N., Vernet, A., Coussirat, M., and Codina, E., 2010, “Numerical Simulation of Turbulent Flow in the Suction Chamber of a Gearpump Using Deforming Mesh and Mesh Replacement,” Int. J. Mech. Sci., 52(10), pp. 1334–1342. [CrossRef]
Ghazanfarian, J., and Ghanbari, D., 2014, “Computational Fluid Dynamics Investigation of Turbulent Flow Inside a Rotary Double External Gear Pump,” ASME J. Fluids Eng., 137(2), p. 021101. [CrossRef]
Magnusson, J., 2011, “Numerical Analysis of the Lubricant Gap in External Gear Pumps Considering Micro Level Surface Features,” Master's thesis, Chalmers University of Technology, Göteborg, Sweden.
Dhar, S., and Vacca, A., 2013, “A Fluid Structure Interaction-EHD Model of the Lubricating Gaps in External Gear Machines: Formulation and Validation,” Tribol. Int., 62, pp. 78–90. [CrossRef]
Dhar, S., and Vacca, A., 2012, “A Novel CFD—Axial Motion Coupled Model for the Axial Balance of Lateral Bushings in External Gear Machines,” Simul. Model. Pract. Theory, 26, pp. 60–76. [CrossRef]
Hsieh, C.-F., 2012. “Fluid and Dynamics Analyses of a Gerotor Pump Using Various Span Angle Designs,” ASME J. Mech. Des., 134(12), p. 121003. [CrossRef]
Frosina, E., Senatore, A., Buono, D., and Olivetti, M., 2014, “A Tridimensional CFD Analysis of the Oil Pump of an High Performance Engine,” SAE, Technical Paper No. 2014-01-1712.
Jasak, H., 1996, “Error Analysis and Estimation for the Finite Volume Method With Applications to Fluid Flows,” Ph.D. thesis, Imperial College of Science, Technology, and Medicine, London, UK.
Weller, H. G., Tabor, G., Jasak, H., and Fureby, C., 1998, “A Tensorial Approach to Computational Continuum Mechanics Using Object-Oriented Techniques,” Comput. Phys., 12(6), pp. 620–631. [CrossRef]
OpenCFD Ltd., 2012, “OpenFoam. The Open Source cfd Toolbox,” Version 2.1.1, http://www.openfoam.org
Patankar, S. V., and Spalding, D. B., 1972, Numerical Prediction of Three-dimensional Flows, Imperial College of Science and Technology Mechanical Engineering Department, London, UK.
Issa, R., 1986, “Solution of the Implicitly Discretised Fluid Flow Equations by Operator-Splitting,” J. Comput. Phys., 62(1), pp. 40–65. [CrossRef]
Versteeg, H. K., and Malalasekera, W., 2007, An Introduction to Computational Fluid Dynamics: The Finite Volume Method, Pearson Education Limited, Essex, UK.
del Campo, D., Castilla, R., Raush, G., Gamez-Montero, P. J., and Codina, E., 2012, “Numerical Analysis of External Gear Pumps Including Cavitation,” ASME J. Fluids Eng., 134(8), p. 081105. [CrossRef]
Gamez-Montero, P. J., Castilla, R., del Campo, D., Ertürk, N., Raush, G., and Codina, E., 2012, “Influence of the Interteeth Clearances on the Flow Ripple in a Gerotor Pump for Engine Lubrication,” Proc. Inst. Mech. Eng., Part D, 226(7), pp. 930–942. [CrossRef]
del Campo, D., 2011, “Analysis of the Suction Chamber of External Gear Pumps and Their Influence on Cavitation and Volumetric Efficiency,” Ph.D. thesis, ETSEIAT—Universitat Politècnica de Catalunya, Terrassa, Spain.
del Campo, D., Castilla, R., Raush, G. A., Gamez-Montero, P. J., and Codina, E., 2014, “Pressure Effects on the Performance of External Gear Pumps Under Cavitation,” J. Mech. Eng. Sci., 228(16), pp. 2925–2937 [CrossRef].
Erturk, N., Vernet, A., Pallares, J., Castilla, R., and Raush, G., 2013, “Small-Scale Characteristics and Turbulent Statistics of the Flow in an External Gear Pump by Time-Resolved PIV,” Flow Meas. Instrum., 29, pp. 52–60. [CrossRef]
Open Cascade, 2012, “Salome6, The Open Source Integration Platform for Numerical Simulation,” http://www.salome-platform.org
Gschaider, B., 2014, “Pyfoam, Wiki page,” http://openfoamwiki.net/index.php/Contrib/PyFoam
Hartinger, M., 2007, “CFD Modeling of Elastohydrodynamic Lubrication,” Ph.D. thesis, Imperial College, London, UK.
Hartinger, M., Dumont, M.-L., Ioannides, S., Gosman, D., and Spikes, H., 2008, “CFD Modeling of a Thermal and Shear-Thinning Elastohydrodynamic Line Contact,” ASME J. Tribol., 130(4), p. 041503. [CrossRef]
Esmailzadeh, H., and Passandideh-Fard, M., 2014, “Numerical and Experimental Analysis of the Fluid-Structure Interaction in Presence of a Hyperelastic Body,” ASME J. Fluids Eng., 136(11), p. 111107. [CrossRef]
Castilla, R., Wojciechowski, J., Gamez-Montero, P., Vernet, A., and Codina, E., 2008, “Analysis of the Turbulence in the Suction Chamber of an External Gear Pump Using Time Resolved Particle Image Velocimetry,” Flow Meas. Instrum., 19(6), pp. 377–384. [CrossRef]
Erturk, N., Vernet, A., Castilla, R., Gamez-Montero, P., and Ferre, J., 2011, “Experimental Analysis of the Flow Dynamics in the Suction Chamber of an External Gear Pump,” Int. J. Mech. Sci., 53(2), pp. 135–144. [CrossRef]

Figures

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Fig. 1

Working principle of an EGP. Fluid is carried from the inlet port to the outlet port in the interteeth spaces between gears and case.

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Fig. 2

Scheme of the meshing region between gears, showing the LA, and the pressure angle

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Fig. 3

Picture of the lateral plate with the decompression slot machined en the outlet port

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Fig. 4

Scheme showing the gear contact region and the flow rate in a case where contact ratio is greater than unity

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Fig. 5

Computational domain with gears, suction pipe and chamber, impulsion pipe and chamber, and decompression slot

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Fig. 6

Mesh for the 2D simulation and detail of the gearing zone

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Fig. 7

3D gear pump mesh. Symmetry plane view.

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Fig. 8

Detail of decompression slot mesh connecting teeth space and impulsion chamber

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Fig. 9

Flowchart of mesh replacement and interpolation

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Fig. 10

The speed-up of the simulation scalability

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Fig. 11

The logistic function for k = 5 and k = 40, with kd = 3, compared with the normal distribution

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Fig. 12

Backlash clearance without contact

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Fig. 13

Flow rate time series in inlet for ɛ=1.0 and ɛ=1.4

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Fig. 14

Flow rate time series in outlet for ɛ=1.0 and ɛ=1.4

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Fig. 15

Velocity vx time series for one gearing cycle in the point Pinlet

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Fig. 16

Pressure time series for one gearing cycle in the point Pinlet

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Fig. 17

Pressure time series for one gearing cycle in the point Poutlet

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Fig. 18

Streamlines for 2D simulation for ɛ=1.4

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Fig. 19

Streamlines for 3D simulation in the symmetry plane, and comparison with experimental results, from Ref. [34]

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Fig. 20

3D view of the streamlines for the numerical simulation

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