Experimental and numerical study of an offset jet with different velocity and offset ratios

Abstract

The present study examines the configuration of an offset jet issuing into either a quiescent medium or a moving stream (co-flowing). The mean velocity and turbulence characteristics of the turbulent offset jet have been investigated using a particle image velocimetry technique at three velocity ratios and for two offset ratios. A numerical simulation of a three-dimensional offset jet has also been carried out by comparing the corresponding results with previous experimental data and our measurements. The numerical investigation was performed by means of the finite volume method together with a second-order turbulent closure model – the Reynolds stress model (RSM) – to examine the behavior of the flow for different velocity ratio and offset ratios. Results give a satisfactory agreement between the experimental data and the calculations. Data from the early flow region clearly show a significant influence of the velocity ratio and the offset ratio on the mean flow and turbulence characteristics.