Parametric study of flow field and mixing characteristics of outwardly injected jets into a crossflow in a cylindrical chamber

Abstract

Flow field and mixing characteristics of coolant radial jets injected radially from multiple nozzles rows of centreline distributer into a heated non-reacting crossflow in a cylindrical chamber is numerically investigated. The study simulates the process of air jets injection in the combustion chambers of gas turbines through discrete holes. Three-dimensional model using ANSYS-FLUENT 14.5 CFD package is used. The effects of jet-mixing ratio, nozzles diameter, distributer diameter, number of nozzles rows, number of nozzles per row on the penetration depth and mixing quality through chamber cross section are parametrically studied. The results are validated with the available experimental data and good agreement are obtained. The results showed that nozzle diameter, distributer diameter and jet-mixing ratio have effects on the penetration depth and the mixing quality compared to the effects of the number of nozzles per row and the number of nozzles rows. The effects are remarkable at high mixing ratio. The integral mixing quality along the chamber cross section increased with increasing mixing ratio, nozzles diameters, number of nozzles per row and number of nozzles rows. Dimensionless correlations for predicting the penetration depth and mixing quality in terms of the controlling parameters are developed.