Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2007.121.126HajikandiHoomanMansooriAbbas1200771The families of K-ε and K-ω turbulence models are performed for axisymmetric confined jets with back pressure and the results are compared with the experimental data. The physical model which is used as a source to evaluate the numerical results consists of a sudden pipe expansion, with an Expansion Ratio (ER) of 3.675. the results show that the realizable K-ε model and RNG K-ε model give a better prediction of the confined jet spreading rate, while the standard K-ε and the family of K-ω models end in overestimate approximations. However, some models have local superiority to the others, in special zones of the flow or give a better prediction of a class of flow parameters or flow characteristics. So, the authors ignore setting forth a special turbulence model for general implementation in numerical calculations for confined jets, but point out the efficiencies and deficiencies of each model.]]>Choudhury, D.,1993Cole, D.R., G. Ahmadi, M. Glause and W. Kvasnak,2003Kolmogrov, A.N.,1942Kooronaki, E.D., H.H. Liakos, M.A. Founti and N.C. Markatos,2001Launder, B.E. and D.B. Spalding,1972Menter, F.R.,1994Prandtl, L.,1925Shih, T.H., W.W. Liou, A. Shabbir and J. Zhu,1998Sinder, M.M.S.,1982Wilcox, D.C.,1988