Measurements of mass flux in a turbulent liquid flow with a chemical reaction

Abstract

Abstract An original technique for simultaneous measurements of concentration and velocity in a turbulent liquid flow with and without a chemical reaction is developed by combining a two‐component He‐Ne laser Doppler velocimeter with a Ar + laserinduced fluorescence technique. The mass flux and eddy diffusivity of mass are estimated from the simultaneous measurements of concentration and velocity in a liquid shear‐free mixing layer downstream of a turbulence grid. The results show that the present measuring technique enables us to simultaneously measure velocity and concentration with high resolutions and that the approximation of the mean gradient diffusion causes about 10% error in estimating the mass flux in a reacting liquid flow.