Monte Carlo simulations of a median-filter technique to discriminate between particle and fluid velocity fields

Abstract

An error analysis is reported of a method to discriminate between the tracer particles used to mark the carrier-phase and the suspended particles in a two-phase flow for particle image velocimetry. The discrimination was obtained through application of a median-filter to two-phase image pairs, generated artificially by a Monte Carlo simulation. A Lamb–Oseen vortex was selected as the simulated flow for both the gas- and solidphases, as it provides a range of velocities within the simulated field. The rotational velocities of both phases were selected to be different, allowing a range of slip velocities to be analysed. Simulations were executed with a range of particle and tracer volumetric loadings, particle sizes and filter widths. This analysis provides much more detail than was previously available on the conditions for which a median filter will accurately discriminate between tracers and larger particles in a real flow.