The Effect of Chemical Reaction on the Mixing Flow Between the Acetic Acid Solution and the Ammonia Solution

Abstract

A basic characteristic of the reacting mixing flow was investigated. The reaction between an ammonia solution [0.1mol/L] and an acetic acid solution [0.1mol/L], which produced ammonia acetic acid solution, was investigated in terms of the effect on the fluid-fluid interface of mixing flow, relative to fluids that did not react. The reaction between these solutions was negligibly exothermic, and the density and other thermo-physical properties were also not much different. The chemical reaction would only affect the mixing flow and the interfacial stability, while turbulence would enhance the chemical reaction. Two experiments were performed. In the first experiment, the mixing flow of an upward round jet and an upward ambient flow was studied. In the second experiment, the interfacial instability was investigated under parallel flow conditions in the rectangular tank. The acidic and alkaline solutions were flowed separately down individual rectangular channel 30 mm in width, and mixed only in a small region of the mixing interface, where the partition between the channels had been removed. The velocity field in the reacting mixing flow was quantitatively measured using the dynamic-PIV and the behavior of the mixing flow was qualitatively investigated using the LIF. The mixing behavior was monitored using a fluorescent dye. It was found that the mixing with chemical reaction was suppressed in both experiments. The jet width, the velocity field and the kinetic energy are qualitatively estimated and discussed.