0
Research Papers

Source Term Based Modeling of Rotating Cavitation in Turbopumps

[+] Author and Article Information
A. G. Vermes

Rolls-Royce plc,
62 Buckingham Gate,
London, SW1E 6AT, UK
e-mail: Adam.Vermes@Rolls-Royce.com

C. Lettieri

Assistant Professor
Faculty of Aerospace Engineering,
Flight Performance & Propulsion Section,
Building 62, Office 7.11,
Kluyverweg 1,
Delft, 2629 HS, The Netherlands
e-mail: c.lettieri-1@tudelft.nl

1Corresponding author.

Manuscript received November 26, 2018; final manuscript received December 9, 2018; published online January 8, 2019. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 141(6), 061002 (Jan 08, 2019) (8 pages) Paper No: GTP-18-1709; doi: 10.1115/1.4042302 History: Received November 26, 2018; Revised December 09, 2018

The recent growth of private options in launch vehicles has substantially raised price competition in the space launch market. This has increased the need to deliver reliable launch vehicles at reduced engine development cost and has led to increased industrial interest in reduced order models. Large-scale liquid rocket engines require high-speed turbopumps to inject cryogenic propellants into the combustion chamber. These pumps can experience cavitation instabilities even when operating near design conditions. Of particular concern is rotating cavitation (RC), which is characterized by an asymmetric cavity rotating at the pump inlet, which can cause severe vibration, breaking of the pump, and loss of the mission. Despite much work in the field, there are limited guidelines to avoid RC during design and its occurrence is often assessed through costly experimental testing. This paper presents a source term based model for stability assessment of rocket engine turbopumps. The approach utilizes mass and momentum source terms to model cavities and hydrodynamic blockage in inviscid, single-phase numerical calculations, reducing the computational cost of the calculations by an order of magnitude compared to traditional numerical methods. Comparison of the results from the model with experiments and high-fidelity calculations indicates agreement of the head coefficient and cavity blockage within 0.26% and 5%, respectively. The computations capture RC in a two-dimensional (2D) inducer at the expected flow coefficient and cavitation number. The mechanism of formation and propagation of the instability is correctly reproduced.

Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Kamijo, K. , Yoshida, M. , and Tsujimoto, Y. , 1993, “ Hydraulic and Mechanical Performance of LE-7 LOX Pump Inducer,” J. Propul. Power, 9(6), pp. 819–826. [CrossRef]
Zoladz, T. , 2001, “ Overview of Rotating Cavitation and Cavitation Surge in the Fastrac Engine LOX Turbopump,” NASA Marshall Space, Huntsville, AL, Report No. 20020016716. https://ntrs.nasa.gov/search.jsp?R=20020016716
Ryan, R. , 1994, “ The Space Shuttle Main Engine Liquid Oxygen Pump High-Synchronous Vibration Issue: The Problem, The Resolution Approach, The Solution,” AIAA Paper No. 94-3153.
Arnone, A. , Boncinelli, P. , Capuani, A. , Spano, E. , and Rebattet, C. , 2001, “ ‘Ariane 5’ TPLOX Inducer Design Strategies to Enhance Cavitating Performance,” Caltech Conference Repository, pp. 1–12. https://pdfs.semanticscholar.org/572f/cbfdd6602345691e04f9bab8e4dabad15091.pdf
Kang, D. , Yonezawa, K. , Horiguchi, H. , Kawata, Y. , and Tsujimoto, Y. , 2009, “ Cause of Cavitation Instabilities in Three-Dimensional Inducer,” Int. J. Fluid Mach. Syst., 2(3), pp. 206–214. [CrossRef]
Horiguchi, H. , Watanabe, S. , and Tsujimoto, Y. , 2000, “ A Linear Stability Analysis of Cavitation in a Finite Blade Count Impeller,” ASME J. Fluids Eng., 122(4), p. 798. [CrossRef]
Tsujimoto, Y. , Kamijo, K. , and Brennen, C. , 2001, “ Unified Treatment of Flow Instabilities of Turbomachines,” J. Propul. Power, 17(3), pp. 636–643. [CrossRef]
Tsujimoto, Y. , Kamijo, K. , and Yoshida, Y. , 1993, “ A Theoretical Analysis of Rotating Cavitation in Inducers,” ASME J. Fluids Eng., 115(1), pp. 135–141.
Brennen, C. , and Acosta, A. , 1976, “ The Dynamic Transfer Function for a Cavitating Inducer,” ASME J. Fluids Eng., 98(2), pp. 182–191.
Brennen, C. , 2013, “ A Review of the Dynamics of Cavitating Pumps,” ASME J. Fluids Eng., 135(6), p. 061301. [CrossRef]
Yonezawa, K. , Aono, J. , Kang, D. , Horiguchi, H. , Kawata, T. , and Tsujimoto, Y. , 2012, “ Numerical Evaluation of Dynamic Transfer Matrixand Unsteady Cavitation Characteristics of an Inducer,” Int. J. Fluid Mach. Syst., 5(3), pp. 126–133. [CrossRef]
Ugajin, H. , Kawai, M. , Okita, K. , Matsumoto, Y. , Kajishima, T. , Kawasaki, S. , and Tomaru, H. , 2006, “ Numerical Simulation of Unsteady Cavitating Flow in a Turbopump Inducer,” AIAA Paper No. 2006-50658.
Hosangadi, A. , Ahuja, V. , and Ungewitter, R. , 2009, “ Simulation of Cavitation Instabilities in Inducers,” Seventh International Conference on Cavitation, Ann Arbor, MI, Aug. 17–22, pp. 2–9. https://deepblue.lib.umich.edu/handle/2027.42/84299
Kang, D. , Watanabe, T. , Yonezawa, K. , Horiguchi, H. , Kawata, Y. , and Tsujimoto, Y. , 2009, “ Inducer Design to Avoid Cavitation Instabilities,” Int. J. Fluid Mach. Syst., 2(4), pp. 439–448. [CrossRef]
Adamczyk, J. J. , 1985, “ Model Equation for Simulating Flows in Multistage Turbomachinery,” NASA Lewis Research Center, Cleveland, OH, Technical Report No. NASA-TM-86869, E-2291. https://ntrs.nasa.gov/search.jsp?R=19850003728
Xu, L. , 2003, “ Assessing Viscous Body Forces for Unsteady Calculations,” ASME J. Turbomach., 125(3), pp. 425–432. [CrossRef]
Kottapalli, A. P. , 2013, “ Development of a Body Force Model for Centrifugal Compressors,” M.S. thesis, Massachusetts Institute of Technology, Boston, MA. https://dspace.mit.edu/handle/1721.1/85697
Defoe, J. J. , and Hall, D. K. , “ Fan Performance Scaling With Inlet Distortions,” ASME Paper No. GT2016-58009.
Defoe, J. J. , and Spakovszky, Z. , “ Shock Propagation and MPT Noise From a Transonic Rotor in Nonuniform Flow,” ASME J. Turbomach., 135(1), p. 011016. [CrossRef]
Sorensen, W. A. , 2014, “ A Body Force Model for Cavitating Inducers in Rocket Engine Turbopumps,” M.Sc. thesis, Massachusetts Institute of Technology, Cambridge, MA. https://dspace.mit.edu/handle/1721.1/93771
Lighthill, M. J. , 1958, “ On Displacement Thickness,” J. Fluid Mech., 4(4), pp. 383–392. [CrossRef]
Drela, M. , 1989, “ Xfoil: An Analysis and Design System for Low Reynolds Number Airfoils,” Low Reynolds Number Aerodynamics, Springer, Berlin.
Zwart, P. J. , Gerber, A. G. , and Belamri, T. , 2004, “ A Two-Phase Flow Model for Predicting Cavitation Dynamics,” Fifth International Conference on Multiphase Flow, Yokohama, Japan, May 30–June 4, Paper No. 152.
Cervone, A. , Bramanti, C. , Rapposelli, E. , and d'Agostino, L. , 2006, “ Thermal Cavitation Experiments on a NACA 0015 Hydrofoil,” ASME J. Fluids Eng., 128(2), pp. 326–331. [CrossRef]
ANSYS®, 2017, “ Academic Research Fluid Dynamics, Release 18.1, Help System, Theory Guide,” ANSYS, Inc., Canonsburg, PA.
Menter, F. R. , 1993, “ Zonal Two Equation k-ω Turbulence Models for Aerodynamic Flows,” AIAA Paper No. 93-2906.
Peters, A. , 2014, “ Ultra-Short Nacelles for Low Fan Pressure Ratio Propulsors,” Ph.D. thesis, Massachusetts Institute of Technology, Cambridge, MA. https://dspace.mit.edu/handle/1721.1/87128
Kawanami, Y. , 1999, “ Estimation of Cavitation Structure on a Hydrofoil and Impulsive Pressure of the Bubble Collapse,” Ph.D. thesis, University of Tokyo, Tokyo, Japan.
Iga, Y. , and Yoshida, Y. , 2011, “ Mechanism of Propagation Direction of Rotating Cavitation in a Cascade,” J. Propul. Power, 27(3), pp. 675–683. [CrossRef]
Greitzer, E. , 1981, “ The Stability of Pumping Systems—The 1980 Freeman Scholar Lecture,” ASME J. Fluids Eng., 103(2), pp. 193–242.
Lettieri, C. , Spakovszky, Z. , Jackson, D. , and Schwille, J. , 2018, “ Characterization of Cavitation Instabilities in a Four-Bladed Turbopump Inducer,” J. Propul. Power, 34(2), pp. 510–520.
Tani, N. , Yamanishi, N. , and Tsujimoto, Y. , 2012, “ Influence of Flow Coefficient and Flow Structure on Rotational Cavitation in Inducer,” ASME J. Fluids Eng., 134(2), p. 021302. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Mechanism of formation and propagation of RC adapted from Kang et al. [5]

Grahic Jump Location
Fig. 3

Schematic representation of the transpiration velocity model. Source terms model the effect of BL displacement on bulk flow.

Grahic Jump Location
Fig. 4

Schematic representation of the cavity blockage model. Cavities are modeled with the transpiration velocity concept in single-phase calculations.

Grahic Jump Location
Fig. 5

Normalized blade cavity length versus cavitation number for a hydrofoil at 6 deg and 8 deg incidence

Grahic Jump Location
Fig. 6

Total-to-static pressure characteristics. Calculations with the combined viscous blockage models capture slope of pump characteristics within 0.26% error.

Grahic Jump Location
Fig. 7

Qualitative comparison between multiphase calculations and cavitation blockage model. The flow displacement due to cavitation is successfully captured.

Grahic Jump Location
Fig. 8

Nondimensional flow displacement from multiphase and single-phase calculations with varying cavitation number. The cavitation blockage model yields agreement within 5% of the high-fidelity calculations.

Grahic Jump Location
Fig. 9

Schematic representation of the 2D inducer cascade proposed by Iga et al. [29] and used for assessment of RC with blockage model

Grahic Jump Location
Fig. 10

Noncavitating inducer pressure coefficient. Viscous and inviscid calculations are compared with the results from Iga et al. [29].

Grahic Jump Location
Fig. 11

Cavitating inducer pressure coefficient. Two-phase calculations identify RC at ϕ = 0.213 and α = 3 deg with 0.1% accuracy of the results of Iga et al. [29].

Grahic Jump Location
Fig. 12

Oscillating blade loadings indicate RC with frequency 1.24 in two-phase viscous calculation

Grahic Jump Location
Fig. 13

RC propagation mechanism captured with cavity blockage model

Grahic Jump Location
Fig. 14

Contours of relative flow angle during RC in (a) multiphase high-fidelity calculations and (b) single-phase inviscid calculations with source term-based model. The mechanism of the instability is captured by the model.

Grahic Jump Location
Fig. 15

Normalized cavity thickness at various incidence angle. Two-phase numerical calculations are compared with inviscid, single phase calculations with the source term-based model.

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In