CFD modelling of flow and mixing characteristics for multiple rows jets injected radially into a non-reacting crossflow

Abstract

CFD parametric study was done of flow and mixing characteristics of coolant radial jets injected outwardly from a centerline multiple rows diffuser into a heated non-reacting crossflow in a cylindrical chamber in three-dimensional model using ANSYS-FLUENT 14.5. The effects of jet-mixing ratio, nozzles diameter, diffuser diameter, number of nozzles rows number of nozzles per row on the penetration depth and mixing quality through chamber cross section were parametrically studied. The simulation results were validated with the available experimental data and good agreement was obtained. The results showed that the nozzle diameter, the diffuser diameter and the jet-mixing ratio have remarkable effects on the penetration depth and the mixing quality compared to the effects of number of nozzles per row and the number of nozzle rows. The penetration depth at downstream, the jet diffuser exit and the mixing quality at centerline of chamber exit are increased ≅46% & ≅49%, respectively, with increasing the jet-mixing ratio from 0.1 to 0.5. Dimensionless correlations in terms of the studied parameters for predicting the penetration depth, mixing quality and maximum temperature difference were developed and presented.