Related Experiment Video
Updated: Jun 1, 2026

Analyzing Mixing Inhomogeneity in a Microfluidic Device by Microscale Schlieren Technique
Published on: June 12, 2015
Hydrodynamics and mass transfer of the coaxial jet mixer in flow injection analysis
V P Andreev1, S B Koleshko, D A Holman
1Institute for Analytical Instrumentation, Russian Academy of Sciences, 26 Rigsky pr., St. Petersburg 198103, Russia, Department of Hydrodynamics, St. Petersburg State Technical University, 29 Polytechnicheskaya st., St. Petersburg 195251, Russia, and Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195-1700.
Abstract:
A coaxial jet mixer that was previously proposed for rapid and efficient mixing under laminar flow conditions has been studied both theoretically and experimentally. A mathematical model that consists of a set of Navie-Stokes equations that determine the flow velocities and three diffusion-convection reaction equations that determine the reactant and product concentrations has been developed. Equations are solved with the help of finite difference techniques for different flow conditions. The quality of sample and reagent mixing is characterized by the mean product concentration and the amount of product produced. Theoretical results are compared with experimental ones for the mixing of bromothymol blue (a pH indicator) in the outer capillary with NaOH in the inner capillary of the jet mixer.
Related Concept Videos
Free Jet
Steady Flow of a Fluid Stream
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
Continuity Equation
The mass flow rate is expressed as:
Accelerating Fluids
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
Steady, Laminar Flow in Circular Tubes
Laminar and Turbulent Flow

