THEORETICAL AND EXPERIMENTAL INVESTIGATIONS OF VELOCITY DISTRIBUTIONS FOR ROUND JETS

  • Seo, Il-Won (Dept. of Civil Engineering, Seoul National Univ.) ;
  • Mohamed S. Gadalrab (Dept. of Civil Engineering, Seoul National University) ;
  • Lyu, Si-wan (Dept. of Civil Engineering, Seoul National University) ;
  • Park, Yong-sung (N4Tech Water Co., Ltd.)
  • Published : 2001.04.01

Abstract

The theoretical treatments on jets, in which the flow is issuing into a stagnant medium, have been based on Prandtl's mixing theory. In this study, using Prandtl's mixing length hypothesis, a theoretical relationship for the velocity profile of a single round jet is derived. Furthermore, Gaussian expression is used to approximate the theoretical relationship, in which the Gaussian coefficient is assumed to be decreasing exponentially as the flow goes far from the orifice. Two data sets for a single round jet performed by tow different techniques of measurement are used to verify the suggested relationships. The theoretical and Gaussian distribution give close results in spite of the difference in approach. The observed mean velocity distributions are in good agreements with the suggested theoretical and Gaussian distributions.

Keywords

References

  1. Chu, P. C. K., Lee, J. H., and Chu, V. H.(1999). 'Spreading of turbulent round jet in co-flow,' J. Hyd. Engrg. ASCE, , 125(2), 193-204 https://doi.org/10.1061/(ASCE)0733-9429(1999)125:2(193)
  2. Daily, J. W. and Harleman, D. R. F. (1966). Fluid Dynamics, Addison-Wesley Publishing Company, INC., New York
  3. Davidson, M. J., Papps, D. A., and Wood, I. R.(1993). The behaviour of merging buoyant jets. Recent research davances in the fluid mechanics of turbulent jets and plumes, NATO ASI Serices E: Applied sciences, Vol. 255, P.A. Davies, and M.J. Valente Neves, eds., Kluwer, Dordreeht, The Netherlands, 465-478
  4. Fischer, B. H., List, E. J., Koh, R. C. Y., Imberger, J., and Brooks, N. H.(1979). Mixing in inland and coastal waters, Academic Press, Inc., New York, N.Y.
  5. Gortler, H. (1942). Berechnug von aufgaben der freien turbulenz auf grund eines neuen naherungsansatzes, ZAMM 22, 244-254
  6. Hinze, J. O. (1959). Turbulence, McGraw-Hill Book Co., New York
  7. Larsen T. (1993). Numerical modelling of jets and plumes-A civil engineering perspective. Recent research advances in the fluid mechanics of turblent jets and plumes, NATO ASI Series E: Applied scineces, Vol. 255, P.A. Davies, M. J. Valente Neves, eds., Kluwer, Dordrecht, The Netherlands, 237-259
  8. Pani, B., and Dash, R. (1983). Three dimensional single and multiple free jets, J. Hyd. Engrg., ASCE, 109(2), 254-269
  9. Raffel, M., Willert, C., and Kompenhans, J. (1998). Particle Image Velocimtry. Springer-Verlag, Berlin, Germany
  10. Rajaratnam, N. (1976). Turbulent Jets, Elsevier Scientific Pubishing Company
  11. Reichardt, H. (1942). Gesetzmassigkeiten der freien turbulenz, VDI-Forschungsheft 414.
  12. Schlicting, H. (1979). Boundary layer theory, 7th ed., McGraw-Hill Book Co., New York
  13. Tollmien, W. (1926). Berechnung turbulenter ausbreiungsvrgange, ZAMM 6, 468-478
  14. Yu, D. Y., Kim, H. S., and Seo, I. W. (1998). Velocity and dilution of the single jet discharged into stagnant water. Third Korea-Japan bilateral symposium on water resources and environmental research, Korean Federation of Science and Technology Societies, Seoul, Korea, 297-302