Skip to main content
SpringerLink
Log in

Flow separation and liquid rundown in a gas-atomization process

  • Published:
Metallurgical Transactions B Aims and scope Submit manuscript

Abstract

“Rundown≓ filming mode was studied in a confined design gas-atomization nozzle of converging/ diverging construction. In this mode, liquid metal runs down to a certain distance up to ≈3 mm on the outer surface of the metal delivery tube in the form of a thin film. Atomization then takes place through the disintegration of this film by the oncoming gas. The rundown effect was simulated by water, and the supersonic gas flow outside the nozzle was visualized by Schlieren photography. It was found that rundown is caused by the liquid being drawn into a separated flow region on the wall of the delivery tube. This separation comes about as a result of the action on the boundary layer of adverse pressure gradients associated with the shock waves in the gas flow. Geometric conditions required for observing rundown are discussed, and a method is outlined for assessing whether a given nozzle design is likely to produce the effect. Evidence is also presented for the filming of the liquid on the tip of the nozzle by radial spreading.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. E. Klar and J.W. Fesko:Metals Handbook, 9th ed., ASM, Metals Park, OH, 1984, vol. 7, pp. 25–51.

    Google Scholar 

  2. J.E. Williams:Metals Handbook, d9th ed., ASM, Metals Park, OH, 1984, pp. 125–31.

    Google Scholar 

  3. A. ünal:Mater. Sci. Technol., 1987, vol. 3, pp. 1029–39.

    Google Scholar 

  4. A. ünal:Royal School of Mines J., 1986, no. 36, pp. 28-30.

  5. A. ünal:Int. J. Rapid Solidification, 1986, vol. 2, pp. 219–29.

    Google Scholar 

  6. A. ünal: inAluminium Technology '86, T. Sheppard, ed., Inst. of Metals, London, 1986, pp. 673–78.

    Google Scholar 

  7. J.S. Thompson:J. Inst. Met., 1948, vol. 74, pp. 101–32.

    Google Scholar 

  8. H.W. Liepmann and A. Roshko:Elements of Gasdynamics, John Wiley, New York, NY, 1957, pp. 144–77.

    Google Scholar 

  9. N.A. Chigier and J.M. Beer:J. Basic Eng. (Trans. ASME), 1964, vol. 86D, pp. 797–804.

    Google Scholar 

  10. A. ünal:Metall. Trans. B, 1989, vol. 20B, pp. 61–69.

    Google Scholar 

  11. H.W. Liepmann, A. Roshko, and S. Dhawan: NACA Report TN 2334, 1951, pp. 1-100.

  12. D.R. Chapman, D.M. Kuehn, and H.K. Larson: NACA Report 13256, 1957, pp. 1-40.

  13. A. Shapiro:The Dynamics and Thermodynamics of Compressible Fluid Flow, Ronald Press Company, New York, NY, 1953, vol. 2, pp. 1130–59.

    Google Scholar 

  14. M.A. Plint and L. Boswirth:Fluid Mechanics—A Laboratory Course, Charles Griffin & Co. Ltd., London, 1978, pp. 93–97. $

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Materials, Imperial College of Science and Technology, Prince Consort Road, SW7 2BP, London, UK

    A. ünal (Lecturer)

Authors
  1. A. ünal
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

ünal, A. Flow separation and liquid rundown in a gas-atomization process. Metall Trans B 20, 613–622 (1989). https://doi.org/10.1007/BF02655918

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02655918

Keywords

Search

Navigation