International Journal of Fluid Machinery and Systems

Korean Society for Fluid machinery (한국유체기계학회)
권호 표지
DOI QR코드

DOI QR Code

Numerical Simulation of Unsteady Cavitation in a High-speed Water Jet

  • Peng, Guoyi (Department of Mechanical Engineering, College of Engineering, Nihon University) ;
  • Okada, Kunihiro (Department of Mechanical Engineering, College of Engineering, Nihon University) ;
  • Yang, Congxin (School of Energy & Power Engineering, Lanzhou University of Technology) ;
  • Oguma, Yasuyuki (Department of Mechanical Engineering, College of Engineering, Nihon University) ;
  • Shimizu, Seiji (Department of Mechanical Engineering, College of Engineering, Nihon University)
  • Received : 2015.11.26
  • Accepted : 2015.12.19
  • Published : 2016.03.31
Download PDF
⟨ Previous Next ⟩

Abstract

Concerning the numerical simulation of high-speed water jet with intensive cavitation this paper presents a practical compressible mixture flow method by coupling a simplified estimation of bubble cavitation and a compressible mixture flow computation. The mean flow of two-phase mixture is calculated by URANS for compressible fluid. The intensity of cavitation in a local field is evaluated by the volume fraction of gas phase varying with the mean flow, and the effect of cavitation on the flow turbulence is considered by applying a density correction to the evaluation of eddy viscosity. High-speed submerged water jets issuing from a sheathed sharp-edge orifice nozzle are treated when the cavitation number, ${\sigma}=0.1$, and the computation result is compared with experimental data The result reveals that cavitation occurs initially at the entrance of orifice and bubble cloud develops gradually while flowing downstream along the shear layer. Developed bubble cloud breaks up and then sheds downstream periodically near the sheath exit. The pattern of cavitation cloud shedding evaluated by simulation agrees experimental one, and the possibility to capture the unsteadily shedding of cavitation clouds is demonstrated. The decay of core velocity in cavitating jet is delayed greatly compared to that in no-activation jet, and the effect of the nozzle sheath is demonstrated.

Keywords

References

  1. Shimizu, S. and Peng, G., 2009, Water jetting technology for LOHAS, Int. Academic Printing Co. Ltd., Tokyo.
  2. Soyama, H. et al., 1996, "High-speed observation of ultrahigh-speed submerged water jets," Experimental Thermal and Fluid Science, Vol. 12, pp.411-416. https://doi.org/10.1016/0894-1777(95)00124-7
  3. Sato, K., Taguchi, Y., and Hayashi S., 2013, "High speed observation of periodic cavity behavior in a convergent-divergent nozzle for cavitating water jet," J. Flow Control, Measurement & Visualization, Vol. 1, pp.102-107. https://doi.org/10.4236/jfcmv.2013.13013
  4. Peng, G., Masuda, K., Shimizu, S., 2013, "Characteristics of cavitating water jet issuing from a sheathed orifice nozzle," Proc. FLUCOME 2013, No. OS7-01-3, pp.1-8.
  5. Peng, G. and Shimizu, S., 2013, "Progress in numerical simulation of cavitating water jets," J. Hydrodynamics, Vol. 25, No.4, pp.502-509. https://doi.org/10.1016/S1001-6058(11)60389-3
  6. Iga, Y. et al., 2003, "Numerical study of sheet cavitation breakoff phenomenon on a cascade hydrofoil," J. Fluids Eng., Vol. 125(4), pp.643-651. https://doi.org/10.1115/1.1596239
  7. Huang, B, Young, Y. L., Wang G. and Shyy W., 2013, "Combined experimental and computational investigation of unsteady structure of sheet/cloud cavitation," J. Fluids Eng., Vol. 135(7), 071301-1. https://doi.org/10.1115/1.4023650
  8. Qin, Z., Bremhorst, K., and Alehossein, H., 2007, "Simulation of cavitation bubbles in a convergent-divergent nozzle water jet," J. Fluid Mechanics, Vol. 573, pp.1-25. https://doi.org/10.1017/S002211200600351X
  9. Iga, Y. and Konno, T., 2012, "Numerical analysis of the influence of acceleration on cavitation instabilities that arise in cascade," Int. J. Fluid Machinery and Systems, Vol. 5 (1), p. 1-9. https://doi.org/10.5293/IJFMS.2011.5.1.001
  10. Peng, G., Shimizu, S., and Fujikawa, S., 2011, "Numerical simulation of cavitating water jet by a compressible mixture flow method," J. Fluid Science and Technology, Vol. 6(4), pp.499-509. https://doi.org/10.1299/jfst.6.499
  11. Tran, T. D., Nennemann, B., Vu, T. C. and Guibault, F., 2015, "Investigation of cavitation models for steady and unsteady cavitating flow simulation," Int. J. Fluid Machinery and Systems, Vol. 8 (4), pp. 240-253. https://doi.org/10.5293/IJFMS.2015.8.4.240
  12. Singhal A. K., Athavale, M. M., Li, H and Jiang, Y., 2002, "Mathematical basis and validation of the full cavitation model," J. Fluids Eng. Vol. 124(3), pp.617-24. https://doi.org/10.1115/1.1486223
  13. Beattie, D. and Whally, P., 1982, "A simple two-phase frictional pressure drop calculation method," Int. J. Multiphase Flow, Vol.8, pp.83-87. https://doi.org/10.1016/0301-9322(82)90009-X
  14. Wilcox, D. C., 2002, Turbulence modeling for CFD, 2nd ed. DCW Industries, California.
  15. Coutier-Delgosha, O., Fortes-Patella, R., and Reboud, J. L., 2003, "Evaluation of the turbulence model influence on the numerical simulations of unsteady cavitations," J. Fluids Eng., 125(1), pp.38-45. https://doi.org/10.1115/1.1524584
  16. Craft, T. J., Gerasimov, A. V., Iacovides, H., 2002, "Progress in the generalization of wall-function treatments," Int. J. Heat & Fluid Flow. Vol. 23(2), pp.148-160. https://doi.org/10.1016/S0142-727X(01)00143-6
  17. Ito, H., Peng, G. and Shimizu, S., 2011, "Submerged abrasive suspension jets issuing from sheathed nozzle with ventilation," Proc. 2011 WJTA-IMCA Conference and Expo, Paper E2.
  18. Ito, H., Peng, G. and Shimizu, S., 2013, "Submerged cutting by air coated abrasive suspension jet (in Japanese)," Trans. Japan Society of Mech. Engr. (B), Vol. 79 (797), pp.61-70. https://doi.org/10.1299/kikaib.79.61

Cited by

  1. Analysis of the Staggered and Fixed Cavitation Phenomenon Observed in Centrifugal Pumps Employing a Gap Drainage Impeller vol.139, pp.3, 2017, https://doi.org/10.1115/1.4034952