Free turbulent flow emanating from a large plane square nozzle: A theoretical and experimental study

Regarding the use of the velocity distribution of turbulent flows of big square plane nozzles, the authors propose the modeling of a turbulent free jet in a wind-tunnel. The free jet mixes with the surrounding fluid, creating turbulence and the jet grows thicker as a result of the exchange of momentum between stagnant air and a portion of the jet. In this study, jets of air ejected from square nozzles of large sizes and flowing into stagnant air are considered. Theoretical solutions based on two different turbulence theories are proposed with coefficients that should be measured experimentally. These coefficients are obtained for a wide range of Reynolds numbers and a correlation is also proposed. In different stations in the axial direction, the velocity distribution appears to have the same shape. This similarity is shown either by theoretical solutions or experimental measurements in this work.