Simultaneous Measurements of Velocity and Reactive Scalar in Plane Liquid Jet with the Second-Order Chemical Reaction

Abstract

In this study, the liquid plane jet with the second-order chemical reaction (A×B→R) is investigated experimentally. The reactants are 1-naphthol (A) and diazotized sulfanilic acid (B), and the product is 4-(4'-sulphophenylazo)-1-naphthol (R), briefly monoazo dyestuff. The main flow contains the species B and the water solution of species A is issued into the main stream by the plane jet. The blue dyestuff (C: Acid Blue 9) is also added into the jet flow and the concentration of species C can be treated as the conserved scalar (which is independent of the above chemical reaction). The concentrations of species C and the product species R are measured simultaneously by the optical fiber probe based on the light absorption spectrometric method, and the concentrations of species A and B are obtained from the conserved scalar theory. The streamwise velocity is measured by the I-type hot-film anemometer. We attempt to measure the concentrations of reactive species and the streamwise velocity simultaneously by the new combined probe which consists of the optical fiber probe and the I-type hot-film probe. First, it is examined whether it is possible to use the combined probe for simultaneous measurement. And then, the concentrations of the reactive species and the streamwise velocity in the plane jet are measured by the combined probe. It is found that the mass flux of reactant species involved in the jet flow (<uγA>) becomes larger and the mass flux of reactant species involved in the main flow (<uγB>) becomes smaller than nonreactive case due to the chemical reaction near the jet exit, while the influence of the chemical reaction on these mass fluxes in the downstream and outer regions is opposite to the influence near the jet exit. The results also show that the mass flux of product species (<uγR>) has negative value near the jet exit and positive value in the other region.