The Combined Use of Flow Visualisation, Electrical Resistance Tomography and Computational Fluid Dynamics Modelling to Study Mixing in a Pipe

Robert B White, Kosta Simic and Phillip R Strode

Commonwealth Scientific and Industrial Research Organisation (CSIRO),
Division of Minerals, Bayview Avenue, Clayton, 3168, Victoria, AUSTRALIA

ABSTRACT

A dyed tracer solution was injected into the central axis of a transparent pipeline and three different techniques were used to investigate the observed mixing process. The resulting dye plume was observed directly and Electrical Resistance Tomography, ERT, was used to measure conductivity profiles at eight discrete locations along the pipe axis. A three-dimensional Computational Fluid Dynamics, CFD, model of the system was also constructed. Three different tracer solutions of different viscosity were used in the study, and all tests were carried out at the same flow conditions. As expected, the viscosity of the tracer strongly influenced the mixing in the pipe and the resulting dye plume was used to indicate tracer dispersion. Analysis of the ERT measurements identified dispersion characteristics that were not apparent from the flow visualisation observations. The CFD model was used to provide a useful link between the observations made using flow visualisation technique and the measurements made using an ERT system.

Keywords ERT, CFD, flow visualisation, mixing, pipe, ejector