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Research Papers: Gas Turbines: Structures and Dynamics

Rotordynamics of a Two-Phase Flow Twin Screw Pump

[+] Author and Article Information
Ameen R. A. Muhammed

Graduate Research Assistant
e-mail: ameen@turbo-lab.tamu.edu

Dara W. Childs

Leland T. Jordan Professor of Mechanical Engineering
e-mail: dchilds@tamu.edu
Turbomachinery Laboratory,
Texas A&M University,
College Station, TX 77843-3123

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Engineering for Gas Turbines and Power. Manuscript received July 14, 2012; final manuscript received November 24, 2012; published online May 20, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 135(6), 062502 (May 20, 2013) (12 pages) Paper No: GTP-12-1278; doi: 10.1115/1.4023490 History: Received July 14, 2012; Revised November 24, 2012

Twin screw pumps are positive displacement machines. Two meshing screws connected by timing gears push the fluid trapped in the screw cavities axially from suction to discharge. Available steady state hydraulic models predict pump performance and axial pressure distribution in the chambers in single- and two-phase flow conditions. However, no model is available for their rotordynamics behavior. Due to the helix angle of the screw, the pressure distribution around the rotor is not balanced, giving rise to both static and dynamic lateral forces. The work presented here introduces a starting point for rotordynamic analysis of twin screw pumps. First, we show that the screw rotor's geometry can be represented by axisymmetric beam elements. Second, we extend the steady state hydraulic model to predict both the static and dynamic lateral forces resulting from the unbalanced pressure field. Finally, hydraulic forces are applied to the rotor to predict static, synchronous, and nonsynchronous responses. Predictions of the dynamic pressure were compared to measurements from the literature and were found to be in good agreement.

Copyright © 2013 by ASME
Topics: Pressure , Screws , Pumps , Rotors , Geometry
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References

Neumann, W., 1991, “Efficient Multiphase Pump Station for Onshore Application and Prospects for Offshore Application,” Proceedings of the 8th International Pump User Symposium, Turbomachinery Laboratory, Texas A&M University, College Station, TX, March 5–7, pp. 43–48.
Shippen, M. E., and Scott, S. L., 2002, “Multiphase Pumping as an Alternative to Conventional Separation, Pumping and Compression,” Proceedings of the 34th PSIG Conference, SPE Reprint, Portland, OR, October 23–25, Vol. 58.
Vetter, G., and Wincek, M., 1993, “Performance Prediction of Twin-Screw Pumps for Two-Phase Gas/Liquid Flow,” Proceedings of the Fluid Engineering Conference (FED), Pumping Machinery, ASME, Washington, D.C., Vol. 154, pp. 331–340.
Prang, A. J., and Cooper, P., 2004, “Enhanced Multiphase FLow Predictions in Twin-Screw Pumps,” Proceedings of the 21st International Pump User Symposium, Baltimore, MD, March 8–11, Turbomachinery Laboratory, Texas A&M University, College Station, TX, pp. 69–76.
Vetter, G., Wirth, W., Korner, H., and Pregler, S., 2000, “Multiphase Pumping With Twin-Screw Pumps—Understand and Model Hydrodynamics and Hydroabrasive Wear,” Proceedings of the 17th International Pump User Symposium, Houston, TX, March 6–9, Turbomachinery Laboratory, Texas A&M University, College Station, TX, pp. 153–169.
Rausch, T., Vauth, Th., Brandt, J.-U., and Mewes, D., 2004, “A Model for the Delivering Characteristic of Multiphase Pumps,” Proceedings of the 4th Annual North American Conference on Multiphase Technology, Banff, Canada, June 3–4, pp. 313–325.
Martin, A. M., 2003, “Multiphase Twin-Screw Pump Modeling for the Oil and Gas Industry,” Ph.D. thesis, Petroleum Engineering Department, Texas A&M University, College Station, TX.
XU, J., 2008, “Modeling of Wet Gas Compression in Twin-Screw Multiphase Pump,” Ph.D. thesis, Petroleum Engineering Department, Texas A&M University, College Station, TX.
Chan, E., 2006, “Wet-Gas Compression in Twin-Screw Multiphase Pumps” M.S. thesis, Petroleum Engineering Department, Texas A&M University, College Station, TX.
Rabiger, K., Maksoud, T. M. A., Ward, J., and Hausmann, G., 2008, “Theoretical and Experimental Analysis of a Multiphase Screw Pump, Handling Gas–Liquid Mixtures With Very High Gas Volume Fractions,” Exp. Therm. Fluid Sci., 32, pp. 1694–1701. [CrossRef]
Rabiger, K., 2009, “Fluid Dynamic and Thermodynamic Behaviour of Multiphase Screw Pumps Handling Gas-Liquid Mixtures With Very High Gas Volume Fractions,” Ph.D. thesis, University of Glamorgan, Treforest, UK.
Hamelberg, F. W., 1966, “Läuferkräfte bei Schraubenpumpen,” Ph.D. thesis, Technical University of Hanover, Hanover, Germany.
Stosic, N., Smith, I., and Kovacevic, A., 2005, Screw Compressors Mathematical Modeling and Performance Calculation, Springer, New York.
Stosic, N., Smith, I. K., Kovacevic, A., and Mujic, E., 2006, “Vacuum and Multiphase Screw Pump Rotor Profiles and Their Calculation Models,” VDI-Ber., 1932, pp. 53–68.
Rao, J. S., Shiau, T., and Chang, J., 1998, “Theoretical Analysis of Lateral Response Due to Torsional Excitation of Geared Rotors,” Mech. Mach. Theory, 33(6), pp. 761–783. [CrossRef]
Lee, A. S., Ha, J. W., and Choi, D.-H., 2003, “Coupled Lateral and Torsional Vibration Characteristics of a Speed Increasing Geared Rotor-Bearing System,” J. Sound Vib., 263, pp. 725–742. [CrossRef]
Childs, D., 1993, Turbomachinery Rotordynamics: Phenomena, Modeling & Analysis, John Wiley & Sons, New York.
Singh, A., 2003, “Modeling Twin-Screw Multiphase Pump Performance During Periods of High Gas Volume Fraction,” M.S. thesis, Petroleum Engineering Department, Texas A&M University, College Station, TX.
Manring, N. D., 2000, “The Discharge Flow Ripple of an Axial-Piston Swash-Plate Type Hydrostatic Pump,” ASME J Dyn. Syst., Meas., Control, 122, pp. 263–268. [CrossRef]
Cho, B. H., Lee, H. W., and OhJ. S., 2000, “Estimation Technique of Air Content in Automatic Transmission Fluid by Measuring Effective Bulk Modulus,” Proceedings of the FISITA World Automotive Congress, Seoul, Korea, June 12–15.
Tullis, J., 1989, Hydraulics of Pipeline: Pumps, Valves, Cavitation, Transients, John Wiley & Sons, New York.
Martino, G., Fontana, N., and Giugni, M., 2008, “Transient Flow Caused by Air Expulsion Through an Orifice,” J. Hydraul. Eng., 134(9), pp. 1395–1399. [CrossRef]
Nelson, H. D., 1980, “A Finite Rotating Shaft Element Using Timoshenko Beam Theory,” ASME J. Mech. Des., 102(4), pp. 793–803. [CrossRef]
Kanki, H., Fujii, H., Hizume, A., Ichimura, T., and Yamamoto, T., 1986, “Solving Nonsynchronous Vibration Problems of Large Rotating Machineries by Exciting Test in Actual Operating Condition,” Proceedings of the IFToMM International Conference on Rotordynamics, Tokyo, Japan, September 14–17, pp. 221–226.

Figures

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Fig. 1

Solid model of a twin-screw pump rotor (dimensions in mm)

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Fig. 2

Screw sections (dimensions in mm)

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Fig. 3

Axisymmetric screw rotor model (dimensions in mm)

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Fig. 4

Response due to cross section imbalance

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Fig. 5

Variation of first torsional natural frequency with torsional coupling stiffness

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Fig. 6

Torsional-lateral gear coupled system

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Fig. 7

First two forward lateral mode shapes without torsional-lateral coupling

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Fig. 8

Torsional-lateral mode shape

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Fig. 10

Twin-screw pump cut away section [9]

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Fig. 11

Steady state hydraulic model algorithm

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Fig. 12

Schematic of the process of opening the last chamber to discharge

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Fig. 13

Gap opening to discharge

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Fig. 14

Unwrapped screw geometry

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Fig. 15

Two dimensional pressure field

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Fig. 16

Dynamic pressure (GVF = 75%, z = 92 mm) test data from Ref. [5]

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Fig. 17

Dynamic pressure (GVF = 75%, z = 92 mm) test data from Ref. [5]

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Fig. 18

Axisymmetric structure model for double thread twin screw pump from Ref. [5]

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Fig. 19

Hydraulic forces and hydraulic forces spectrum in x direction at four axial locations ((z) in mm)

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Fig. 20

Hydraulic forces and hydraulic forces spectrum in y direction at four axial locations ((z) in mm)

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Fig. 21

Nonsynchronous dynamic response in the x direction

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