Mixing with multiple circular turbulent jets

Abstract

This paper presents the results of a laboratory study investigating chemical mixing in an open channel with multiple circular turbulent jets. The experiments were carried out for a, which is the ratio of the velocity of the jets to that of the crossflow, varying from 8 to 16, with a combination of coflowing and crossflowing jets and only crossflowing jets. The number of ports for the jets was varied for 20 to 36 and the spacing between the ports was varied from 12d to 24d where d is the diameter of the ports. Concentration measurements covered the relative distance x/d=2000, where x is the longitudinal distance from the diffuser. The dimensionless mixing distance cum/d at which the standard deviation of the concentration field reached a value of 5% was equal to 25000 where xm is the mixing distance. The results indicate that a diffuser with turbulent crossflowing jets could be an alternative to mechanical methods for achieving mixing of chemicals in open channels in water treatment plants.