Results from a two-dimensional turbulent diffusion-model for dispersion and deposition of droplets in horizontal annular dispersed gas/liquid flow

A previously used one-dimensional Turbulent Diffusion-model is extended to two dimensions. A quasi-stationary annular dispersed gas/liquid flow is simulated by adding the contributions for different particle sizes of a large number of annular line sources from roll wave tops in the upstream direction. One or more local maxima in the droplet concentration are predicted, if droplet sources are present all along the tube wall. A local maximum in the concentration has been found in experiments as well, but it was always solely attributed to the presence of a secondary gas flow. The droplet deposition flux as calculated in the two-dimensional model shows good agreement with a previously derived analytical expression for the droplet deposition flux. Finally we derive how the two-dimensional deposition flux depends on the Stokes- and Froude-numbers. For an arbitrary Froude-number it is predicted droplets up to which Stokes-number are able to deposit at the top of the tube.