(438d) Validation of Multiphase Mean Age Theory

A new method for determining mean age in multiphase mixtures has been developed and validated against experimental data.  While preliminary results have been presented previously connecting theory to application, this study focuses on experimental validation of the fundamental theory to provide a rigorous foundation upon which to build future applications.

Scalar transport equations were solved to track a secondary phase independently from the bulk fluid.  Each phase has its own scalar associated with it.  In this way, mean age and residence time distributions (RTDs) can be determined for each phase separately.  A two-phase oil/water system flowing in a pipeline was simulated to determine the RTDs at multiple locations for both phases using our steady state multi-phase mean age technique.  These data were compared against the RTDs generated from a traditional transient CFD simulation, and verified against experimental results.  All three methods generated RTDs with similar mean residence times and variances, with differences as low as 4%. 

This method provides the same benefits of traditional mean age theory, primarily obtaining local time-dependent data from steady state simulations.  Many important long time-scale applications are envisioned such as platelet settling in the human vasculature and diseased hearts, solids settling in lakes and streams, pollutant dispersion in air, and solids dispersion in chemical reactor systems.