Experimental and Numerical Investigation of Turbulence Features of an Axisymmetric Air Jet

Abstract

Axisymmetric liquid and gas jets have been investigated in the literature issuing from nozzles of different diameters and different geometry. Reynolds numbers (calculated from the parameters at the exit of the nozzle) are also usually very different. What is common in these papers is that the dimensionless velocity distributions and turbulence properties in the axisymmetric jet show self-similar features some distance downstream of the nozzle. In this paper, we investigate whether these self-similar features are held for a special nozzle where three jets of different directions are merged and mixed in a chamber before leaving the nozzle. Experimental velocity measurements (by constant temperature anemometry, CTA) and numerical simulations (by ANSYS Fluent) were carried out simultaneously. Computational and experimental results showed satisfactory agreement. Our results also compared reasonably well with those in the literature, considering that they are based on different nozzles and different flow conditions.