M. H. Gazzah et al. / Natural Science 2 (2010) 635-640

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640

the mean velocity decay constant Ku, the spreading rate

2/1

u

S and the centerline value of the velocity fluctuation

intensities has been presented. The predictions agree

reasonably well with the very recent experimental study

in the literature for axisymmetric jets. The major visible

effect of the co-flow is the jet decay rate reduction, in

comparison with the free jet case. However, based on

entrainment definition, it is mainly shown that the co-

flow reduce the air entrainment.

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